How To test the Diesel High-Pressure system

[FrenchMike]

Hi all,

In case of non starting (preferably hot),Camsensor is generally incriminated.
But we have to know the behaviour of the common rail pressure in order to rule out a possible injector leak back.

Here is a easy way to do it:

YOU NEED:

-a lowcost multimeter (DC 2 volt range)
-one or two alligator clips with pin associated (as already describe somewhere)


PROCEDURE

1 Disconnect the camsensor.
2 Pin throught the insulation of the blue/black wire (the other green/brown
is the ground.
to pick up the fuel rail pressure signal.
3 turn the key position 2 (you must read 0.5 volts)

4 Crank for 4 secondes then release the key.

If you get a chart like the green one,then,you have no significant leak.

http://rovermg1.free.fr/rovermg/thumbnails/Bjt8KYDWZzHn6NTpIbzT.jpg (http://rovermg1.free.fr/rovermg/images/Bjt8KYDWZzHn6NTpIbzT.jpg)
http://www.the75andztclub.co.uk/forum/attachment.php?attachmentid=6477&d=1285341880


Camsensor test:
http://rovermg1.free.fr/rovermg/thumbnails/b1hpuLgdmydFJAGrwDcg.jpg (http://rovermg1.free.fr/rovermg/images/b1hpuLgdmydFJAGrwDcg.jpg)
http://rovermg1.free.fr/rovermg/images/b1hpuLgdmydFJAGrwDcg.jpg

Low pressure test
http://rovermg1.free.fr/rovermg/thumbnails/HSoUXGZ6UxNVgNm2MP0h.jpg (http://rovermg1.free.fr/rovermg/images/HSoUXGZ6UxNVgNm2MP0h.jpg)
http://rovermg1.free.fr/rovermg/images/HSoUXGZ6UxNVgNm2MP0h.jpg

High pressure test.

http://rovermg1.free.fr/rovermg/thumbnails/xtlYHEoNI7hG2NRREqcr.jpg (http://rovermg1.free.fr/rovermg/images/xtlYHEoNI7hG2NRREqcr.jpg)
http://rovermg1.free.fr/rovermg/images/xtlYHEoNI7hG2NRREqcr.jpg

In case of low values,an injector leakback test is recommanded.

http://rovermg1.free.fr/rovermg/thumbnails/d5Wzna8fXY3JJk6S7DNw.jpg (http://rovermg1.free.fr/rovermg/images/d5Wzna8fXY3JJk6S7DNw.jpg)
http://rovermg1.free.fr/rovermg/images/d5Wzna8fXY3JJk6S7DNw.jpg

Check the HP pump regulator gaskets as well.

http://rovermg1.free.fr/rovermg/thumbnails/J5U00eSpcw46t8qrPYiW.jpg (http://rovermg1.free.fr/rovermg/images/J5U00eSpcw46t8qrPYiW.jpg)
http://rovermg1.free.fr/rovermg/images/J5U00eSpcw46t8qrPYiW.jpg

MAF test

http://rovermg1.free.fr/rovermg/thumbnails/OfkokgAqqCz6Q464JhDL.jpg (http://rovermg1.free.fr/rovermg/images/OfkokgAqqCz6Q464JhDL.jpg)
http://rovermg1.free.fr/rovermg/images/OfkokgAqqCz6Q464JhDL.jpg

Cranckshaft sensor is easely tested by looking at the tachometer needle during cranking.

Don't forget;if starting with easy start,it's not an electrical issue but likely an injector fault.

Mike

Enlarged Thumbnails.....

http://www.the75andztclub.co.uk/forum/attachment.php?attachmentid=6475&d=1285341084

[simpsora]

Another simple but very informative diagnostic test. Could save members lots of time and money if unsure about any starting problems.
PS my FBH started yesterday (5 deg ) first time this season !!
Thanks again for all your work for 'the forum'
Regards , Robert

[FrenchMike]

Another simple but very informative diagnostic test. Could save members lots of time and money if unsure about any starting problems.
PS my FBH started yesterday (5 deg ) first time this season !!
Thanks again for all your work for 'the forum'
Regards , Robert

Thanks,Robert

That's nothing , only happy to be useful still ! :}


Mike

[Starman]

How quick and easy.

Mike, forgive me asking silly questions but a) will this show a small leakback if it exists, and b) how much would the voltage change by vs the amount of leak?

Many thanks and well done for posting this up.

Regards Steve.

[FrenchMike]

How quick and easy.

Mike, forgive me asking silly questions but a) will this show a small leakback if it exists, and b) how much would the voltage change by vs the amount of leak?

Many thanks and well done for posting this up.

Regards Steve.

Hi,Steve

That's a good question.

The green plot is get from my own car (she runs well)
I guess, if there is some leak (in particular injector),it
must be something like the supposed red plots!

Knowing that a lack of pressure prevent starting the engine

But effectively, if someone with a leak could make this measurement,
It should be interesting!

Mike

[chrissyboy]

:DHi all,

In case of non starting (preferably hot),Camsensor is generally incriminated.
But we have to know the behaviour of the common rail pressure in order to rule out a possible injector leak back.

Here is a easy way to do it:

YOU NEED:

-a lowcost multimeter (DC 2 volt range)
-one or two alligator clips with pin associated (as already describe somewhere)


PROCEDURE

1 Disconnect the camsensor.
2 Pin throught the insulation of the blue/black wire (the other green/brown
is the ground.
to pick up the fuel rail pressure signal.
3 turn the key position 2 (you must read 0.5 volts)

4 Crank for 4 secondes then release the key.

If you get a chart like the green one,then,you have no significant leak.

http://rovermg2.free.fr/rovermg/thumbnails/5tK9BUDrdDv4MBkqOQDi.jpg (http://rovermg2.free.fr/rovermg/images/5tK9BUDrdDv4MBkqOQDi.jpg)

Now,you can see the Camsensor side;but before buying one,have a look here:

http://www.the75andztclub.co.uk/forum/showthread.php?t=65916

All comments are welcome :}

Mike

watch out for all the cranking as the cat will build up with un burnt fuel .as your just testing the ecu is sending a 5volt to it and the ecu is recieving a signal back make sure it cant pump fuel ..just pull the pump fusethe best things to use or the snap on hook and tighten ones so you get a constant un interupted flow of currant,check for continuinity if that is there it is working as it should

[al_dente]

I thought I'd give this a try to see if it helped shed any light on my car's cutting out issue.

When I'd connected my voltmeter, I had 0.465 volts on the meter. When I cranked the engine, the reading didn't change.

I thought I'd see what happened if I reconnected the cam sensor. The car wouldn't start with the cam sensor connected. I then disconnected the voltmeter and tried again - the car started.

So, I have two questions:

1) becasue the volt reading didn't change, does it mean I've done something wrong - or could it indicate that my injectors are leaking really badly?

2) is it right that the car wouldn't start with the voltmeter connected to the blue and brown wires?

Cheers

Al

[FrenchMike]

I thought I'd give this a try to see if it helped shed any light on my car's cutting out issue.

When I'd connected my voltmeter, I had 0.465 volts on the meter. When I cranked the engine, the reading didn't change.

I thought I'd see what happened if I reconnected the cam sensor. The car wouldn't start with the cam sensor connected. I then disconnected the voltmeter and tried again - the car started.

So, I have two questions:

1) becasue the volt reading didn't change, does it mean I've done something wrong - or could it indicate that my injectors are leaking really badly?

2) is it right that the car wouldn't start with the voltmeter connected to the blue and brown wires?

Cheers

Al

Hi Al,

A high impedance voltmeter (several Mohms)must not disturb the pressure sensor output ! (low impedance DC signal)
And then of course you can run the engine!

however no use to have the engine running ; It is the pressure decrease
whicht is interesting in that case.

Mike

[Jules]

:D

watch out for all the cranking as the cat will build up with un burnt fuel .as your just testing the ecu is sending a 5volt to it and the ecu is recieving a signal back make sure it cant pump fuel ..just pull the pump fusethe best things to use or the snap on hook and tighten ones so you get a constant un interupted flow of currant,check for continuinity if that is there it is working as it should

That wouldn't work Chris.
There will be no fuel pressure to measure if you pull the fuse:shrug:

[Mike Noc]

That wouldn't work Chris.
There will be no fuel pressure to measure if you pull the fuse:shrug:

Agree Jules but also there won't be any fuel injected anyway because the cam sensor is disconnected.

Mike.

[Jules]

FrenchMike

Another observation from me is that the 0.5 volts rises to 0.7 - 0.72volts (rail sensor) before cranking.

This equates to 350kPA (3.5 BAR) which of course is the LP fuel pressure.
The HP pump and rail pipes should see this pressure prior to cranking.
That test can bypass most other tests and time wasting and it proves fuel is being fed from the tank.

Incidentally a CDT will start with rail sensor disconnected (but won't rev)
Be careful doing this as the ECU goes to safe mode
(the open circuit rail circuit actually sends a reading of 400,000 kPA to ECU!!)

[FrenchMike]

FrenchMike

Another observation from me is that the 0.5 volts rises to 0.7 - 0.72volts (rail sensor) before cranking.

This equates to 350kPA (3.5 BAR) which of course is the LP fuel pressure.
The HP pump and rail pipes should see this pressure prior to cranking.
That test can bypass most other tests and time wasting and it proves fuel is being fed from the tank.

Incidentally a CDT will start with rail sensor disconnected (but won't rev)
Be careful doing this as the ECU goes to safe mode
(the open circuit rail circuit actually sends a reading of 400,000 kPA to ECU!!)

Thanks Jules,

Interesting to know ,
so with only one measurement,one can learn lot of things ...

[john493]

Had a problem with my 2003 CDTi this afternoon - started normally, drove for about 15 minutes, stopped the engine. About 2 mins later tried to re-start & it turned over but would not fire.
I left it for 5 minutes, then it started normally. The UB fuel pump sounds a bit noisy, not sure if it's noisier than normal. I can hear the IT pump running now, although when I first listened, I couldn't hear it.
Where do I start testing ?
BTW, I looked at the pressure sensor on the fuel filter, it has 3 wires, yellow/blue, green/purple, green/black - these colours appear different from those listed for testing.
Thanks
John

[FrenchMike]

Had a problem with my 2003 CDTi this afternoon - started normally, drove for about 15 minutes, stopped the engine. About 2 mins later tried to re-start & it turned over but would not fire.
I left it for 5 minutes, then it started normally. The UB fuel pump sounds a bit noisy, not sure if it's noisier than normal. I can hear the IT pump running now, although when I first listened, I couldn't hear it.
Where do I start testing ?
BTW, I looked at the pressure sensor on the fuel filter, it has 3 wires, yellow/blue, green/purple, green/black - these colours appear different from those listed for testing.
Thanks
John

There are 3 wires

+5volt from ECU purple/green (the middle one)
earth from ECU Black
signal sensor output blue/yellow

If you get around 4 volts on the signal wire, all the low pressure side is OK

Mike

[john493]

Thanks Mike - 2 questions:
Testing on the fuel rail sensor, I see the 0.5v with ignition on, I see the 1.2 volts when cranking. When exactly should I be seeing 0.7 volts ?
The 4 volt signal on the fuel filter sensor is OK.

So I'm thinking my cam sensor is suspect, (temperature-related), though today the car is starting with no problems - I've taken a gamble and ordered a used sensor off eBay.
However, I did try to test for the 9 volts at the sensor when cranking, but the wiring colours again are different to those pictured on this thread. I was thinking the right hand red/white was the signal line, but it's still at 12 volts when cranking. So which one is the signal wire ? (as car starts, am taking it the sensor is not faulty at the moment.) See picture of my sensor wiring:

http://www.the75andztclub.co.uk/forum/attachment.php?attachmentid=48761&d=1431706453

[FrenchMike]

Thanks Mike - 2 questions:
Testing on the fuel rail sensor, I see the 0.5v with ignition on, I see the 1.2 volts when cranking. When exactly should I be seeing 0.7 volts ?
The 4 volt signal on the fuel filter sensor is OK.

So I'm thinking my cam sensor is suspect, (temperature-related), though today the car is starting with no problems - I've taken a gamble and ordered a used sensor off eBay.
However, I did try to test for the 9 volts at the sensor when cranking, but the wiring colours again are different to those pictured on this thread. I was thinking the right hand red/white was the signal line, but it's still at 12 volts when cranking. So which one is the signal wire ? (as car starts, am taking it the sensor is not faulty at the moment.) See picture of my sensor wiring:

1.2 volt while cranking seems correct (around 300 bars) allowing ignition.

About the camshaft sensor,the signal is the middle one.
earth (Brown) in the right .
Power +12 volt on the left (red/white)

Obviously ,it's when at fault ,that you have to take the measurements.

Carry out a injector leakback as well :}

Good luck

Mike

[john493]

Well I changed the cam sensor 2 weeks ago & had no further problems until today, when after a 2 mile drive, the car was parked for 10 minutes then would not restart. Turned over but does not fire. Left it for another 5 minutes, then it started straight away. Clearly the original cam sensor is OK so I'll re-fit it. (The misses was using the car at the time, she did tell me that the electric windows would not work when this happened, though I didn't verify this myself ! Is this a clue ?)
Fuel Tank was 75% full.
Not much chance to do any proper testing with such an intermittent fault.
It's a CDTi, 2003.

What's the most likely cause of a heat-sensitive fault like this ?

Thanks,
John

[FrenchMike]

Try to carry out a injector leakback test while warm or hot :

see:
http://www.the75andztclub.co.uk/forum/showthread.php?p=2006584#post2006584

[john493]

Thanks Mike I've not got the kit to do a leak back test, I'll see if I can borrow one !
I've seen DIY kits with small bottles & pipe, but I'll need the connectors to fit on the injectors too.

[FrenchMike]

Thanks Mike I've not got the kit to do a leak back test, I'll see if I can borrow one !
I've seen DIY kits with small bottles & pipe, but I'll need the connectors to fit on the injectors too.

You don't need a special equipment ,only buy one meter of vinyl tube:

(sorry for the french !)

49038
http://www.the75andztclub.co.uk/forum/attachment.php?attachmentid=49038&d=1432458316

Mike

[john493]

Thanks Mike I'll try it.

[john493]

I'm hoping to do the leak off test tomorrow, weather permitting.
I'm also on the UK Volvo forum & found this link to clean the injectors by running the engine on neat cleaner - any views on whether this is feasible on my 75 CDTi ? If so, where would be the best place to connect the pipes ? https://www.youtube.com/watch?v=xYsXHC2-PSw

[FrenchMike]

I'm hoping to do the leak off test tomorrow, weather permitting.
I'm also on the UK Volvo forum & found this link to clean the injectors by running the engine on neat cleaner - any views on whether this is feasible on my 75 CDTi ? If so, where would be the best place to connect the pipes ? https://www.youtube.com/watch?v=xYsXHC2-PSw

A guess your 2002 car has accumulated lot of miles and so a simple cleaning won't help ...:shrug:

[john493]

Completed the leak off test today(thanks Mike for the instructions), ran the engine for 2 minutes, the black line on the jars is 20ml.
So it looks like I've got a fairly leaky set of injectors, with no. 3 leaking about 30ml in 2 mins, the others on the limit at 20ml approx.

I'm guessing I need to take the injectors out for reconditioning - I know I've got to remove the inlet manifold first - are the injectors likely to come straight out, or is a puller needed ?

http://www.the75andztclub.co.uk/forum/attachment.php?attachmentid=49240&d=1433252699

[FrenchMike]

Completed the leak off test today(thanks Mike for the instructions), ran the engine for 2 minutes, the black line on the jars is 20ml.
So it looks like I've got a fairly leaky set of injectors, with no. 3 leaking about 30ml in 2 mins, the others on the limit at 20ml approx.

I'm guessing I need to take the injectors out for reconditioning - I know I've got to remove the inlet manifold first - are the injectors likely to come straight out, or is a puller needed ?

Well,at least number 3 is faulty ...

Lot of threads about it ,for instance :

an old one from "blackadder"

I removed my injectors with ease after 120,000 miles in place.

Dump plenty penetrating oil ou vinaigre into the injector wells and run the car for a week or so to give it time to work its way down the wells.

When removing the injectors, follow the procedure above or Haynes, that's OK, but remove the 2 small nuts holding each injector clamp LEAVING THE STUDS IN PLACE. Do not try to remove these studs it will cost you.

You can try the blow-out method described above, no probs.

If one sticks, remember the injectors should be free to rotate a little in their now loosened clamps without damaging the studs, so they can be freed by putting a piece of pine wood against the injector's threaded fuel inlet nozzle and tapping one way then the other with a hammer to rotate the injector a few degrees.
Rotation of the injector is then clearly seen and this tells you it is freed off.

Then use a large blade screwdriver to lever gently upwards on the underside of the fuel inlet nozzle, again protect the thread with a sliver of soft wood. Injector should now just pop out.

WARNING
If any injector will not rotate, even using a heavier sideways knock, its probable that you will have to damage the injector to remove it or leave it to a trusted Garage.
Plenty of threads you can find on trouble with injectors.


Good luck

Mike

[john493]

Well, I ran the engine on 1 litre of liquid moly diesel purge - I unplugged the in-tank pump and connected the diesel purge container to the input of the under-bonnet pump - it seemed to work ok - I stopped the engine to top up the container, then the car would not re-start - the UB pump did not run, though power was present - a quick tap with the end of a screwdriver and the pump started - so that's my problem - I've ordered a new pump.
(also tested the in-tank pump which delivers fuel OK for about 15 secs at the input pipe to the UB pump once ignition turned on)

[FrenchMike]

Well, I ran the engine on 1 litre of liquid moly diesel purge - I unplugged the in-tank pump and connected the diesel purge container to the input of the under-bonnet pump - it seemed to work ok - I stopped the engine to top up the container, then the car would not re-start - the UB pump did not run, though power was present - a quick tap with the end of a screwdriver and the pump started - so that's my problem - I've ordered a new pump.
(also tested the in-tank pump which delivers fuel OK for about 15 secs at the input pipe to the UB pump once ignition turned on)

That's clear ,you UBP is dead ...may be ,you could forget injectors for the moment
So my LP test must show much less than 3.9 volts !

:shrug:

[bladerunner]

so, after having a cold starting problem I've read through this and I think my in tank pump might have failed,I cant hear it buzzing at all now. its only been in a couple of years as well. symptoms are poor cold starting, ub pump seems noisy and also seems to pump for a long time after ignition on and I've just done the voltage test on the fuel pressure switch and with the ignition on I get 1.6 volts, start the car and it jumps up to 3.8 volts then switch engine off and the voltage slowly drops back to 1.6 volts.would I be correct in my assumption about the pump?

[FrenchMike]

so, after having a cold starting problem I've read through this and I think my in tank pump might have failed,I cant hear it buzzing at all now. its only been in a couple of years as well. symptoms are poor cold starting, ub pump seems noisy and also seems to pump for a long time after ignition on and I've just done the voltage test on the fuel pressure switch and with the ignition on I get 1.6 volts, start the car and it jumps up to 3.8 volts then switch engine off and the voltage slowly drops back to 1.6 volts.would I be correct in my assumption about the pump?


You may have an intermittent issue with one pump or the other ?
As long as you get 3.8 volt ,the pressure is sufficient to feed the HP pump.

At 2.5 volt = 1.7 bars you enter in emergency mode :shrug:

What about the HP sensor value ? (measure preferably while cold)

If too low,see HP regulator O ring or injector leak....

[bladerunner]

I'm going to have a better look at it tomorrow. I know its not very scientific but I disconnected the fuel pipe into the filter and switched the ignition on to see what the fuel flow was like and the jet of fuel didn't even get past the radiator grill. I would have thought it would have shot 5 or 6 feet at least.

[FrenchMike]

I'm going to have a better look at it tomorrow. I know its not very scientific but I disconnected the fuel pipe into the filter and switched the ignition on to see what the fuel flow was like and the jet of fuel didn't even get past the radiator grill. I would have thought it would have shot 5 or 6 feet at least.

Not stupid but usually it's an ON /OFF matter.
If HP too low for some reason,no ignition ,so no start :shrug:

[bladerunner]

Stupid question. if I take the ubp off and switch the ignition on fuel should shoot out of the pipe. If it doesn't or just dribbles/bubbles can I assume the itp is not working? Btw. Tank is full to the brim. I filled it on the way home from work after it struggled to start

[Mike Noc]

No it won't shoot out, but you should get a steady flow of fuel from the ITP.

[Jules]

so, after having a cold starting problem I've read through this and I think my in tank pump might have failed,I cant hear it buzzing at all now. its only been in a couple of years as well. symptoms are poor cold starting, ub pump seems noisy and also seems to pump for a long time after ignition on and I've just done the voltage test on the fuel pressure switch and with the ignition on I get 1.6 volts, start the car and it jumps up to 3.8 volts then switch engine off and the voltage slowly drops back to 1.6 volts.would I be correct in my assumption about the pump?


Depends what brand of pump was fitted.
The cheapo non genuine VDO pumps tend only to last 1-2 years.


Have a look here for quality pumps.

http://www.the75andztclub.co.uk/forum/showthread.php?p=2256411#post2256411

Another valid test I suggest is to connect the output of the filter to a can.
The flow rate of good pumps is 2 ltrs per minute.

The presure is approx 350kpa but as it coming through a ID bore of approx 6mm it's not going to shoot out more than a few inches.


Let us know your findings.

Jules

[bladerunner]

Depends what brand of pump was fitted.
The cheapo non genuine VDO pumps tend only to last 1-2 years.




Jules

It was one of these I fitted http://www.mkon.co.uk/apps/webstore/products/show/2931961

[FrenchMike]

2 ltrs per minute.

33 minutes to empty the tank ...
much more than the engine consumes ,fortunately..:getmecoat:

[Jules]

It was one of these I fitted http://www.mkon.co.uk/apps/webstore/products/show/2931961



If it was VDO it will still be good.
Mkon also sells after market (Energy brand) which have a very limited life in our experience !!

[bladerunner]

well todays findings. unplugged the ubp and switched the ignition on and silence from the itp. disconnected the fuel line into the filter and put it in a milk bottle, turned ignition on and nothing coming out so i think I can safely assume its the itp at fault.just checked the 30amp fuse and thats fine as well, might just have a quick look at the wiring to the pump just in case,even though that means fighting the rear seat.

[FrenchMike]

If it was VDO it will still be good.
Mkon also sells after market (Energy brand) which have a very limited life in our experience !!

Hi Jules,you have an email ...:}

[FrenchMike]

well todays findings. unplugged the ubp and switched the ignition on and silence from the itp. disconnected the fuel line into the filter and put it in a milk bottle, turned ignition on and nothing coming out so i think I can safely assume its the itp at fault.just checked the 30amp fuse and thats fine as well, might just have a quick look at the wiring to the pump just in case,even though that means fighting the rear seat.

The two pumps ares powered in parallel from the ECU ,via a relay ...

Is your plenum dry ?

[bladerunner]

plenums bone dry. finally got to the wiring for the it itp and while the ubp is pumping I have 12 volts at the white wire and the green and black wire. as soon as the ubp stops pumping the white wire loses power which suggests to me the relay and associated wiring is all in order. the green and black stays live all the time.theres nothing at all happening at the itp, cant feel any vibration,hear anything at all so I'm pretty sure I need a new one.

[FrenchMike]

plenums bone dry. finally got to the wiring for the it itp and while the ubp is pumping I have 12 volts at the white wire and the green and black wire. as soon as the ubp stops pumping the white wire loses power which suggests to me the relay and associated wiring is all in order. the green and black stays live all the time.theres nothing at all happening at the itp, cant feel any vibration,hear anything at all so I'm pretty sure I need a new one.

And in these conditions ,you get 3.8 volt on the LP sensor ?

[bladerunner]

yes, 3.8 volts at the lp sensor

[FrenchMike]

yes, 3.8 volts at the lp sensor

humm, and the UBP is gurgling ?
How much fuel in the tank ?

[bladerunner]

I filled it to the brim yesterday afternoon and drove it about 10 miles home

[FrenchMike]

Please ,have a look at the HP value ....

[Jules]

plenums bone dry. finally got to the wiring for the it itp and while the ubp is pumping I have 12 volts at the white wire and the green and black wire. as soon as the ubp stops pumping the white wire loses power which suggests to me the relay and associated wiring is all in order. the green and black stays live all the time.theres nothing at all happening at the itp, cant feel any vibration,hear anything at all so I'm pretty sure I need a new one.


What price did you pay for ITP from Mkon?
He sells 2 completely different qualities.

[bladerunner]

And in these conditions ,you get 3.8 volt on the LP sensor ?

sorry my bad I'm getting myself confused now, I got 3.8 volts with the engine running but 1.4 ish with the ignition on and engine off. I've had enough for today after fighting the rear seat., I'll check the HP tomorrow.

[bladerunner]

What price did you pay for ITP from Mkon?
He sells 2 completely different qualities.

If I remember correctly it was somewhere around £150-£160 for both

[FrenchMike]

sorry my bad I'm getting myself confused now, I got 3.8 volts with the engine running but 1.4 ish with the ignition on and engine off. I've had enough for today after fighting the rear seat., I'll check the HP tomorrow.

No need engine running !
Don't look elsewhere ....1.4 v is NOT ENOUGH ;your ITP is dead ...

Follow the Jules'advices ;fit a good one..:shrug:

Mike

[bladerunner]

Just ordered one from Jules's Ebay store. Thanks for all your help, I'll let you know when its fitted and up and running.

[bladerunner]

pumps arrived, just got a quick question though it rattles as if theres something loose inside it, is this normal?

[Jules]

It's a one way ball valve at the top.
The rattle is a good sign !!

I'm guessing the brand you take out will have Energy written on it ;)

[bladerunner]

well all done and everything seems to be working fine. took about two hours in total and the worst bit was getting the $%$%^%^ seat off and back on again. I do have a little tip to pass on though, to separate the two halves of the pump housing someone suggested using three screwdrivers, I found it much easier to slide a thin screwdriver down either side of the clips and ease two 30mm round wire nails down either side of each clip, the two halves just pull apart then. Oh and this is the cars last chance, if it breaks down again its going.

http://i707.photobucket.com/albums/ww73/chrissoftley/IMG_2014_zpsyziio3ba.jpg (http://s707.photobucket.com/user/chrissoftley/media/IMG_2014_zpsyziio3ba.jpg.html)

[Mike Noc]

Oh and this is the cars last chance, if it breaks down again its going.

http://i707.photobucket.com/albums/ww73/chrissoftley/IMG_2014_zpsyziio3ba.jpg (http://s707.photobucket.com/user/chrissoftley/media/IMG_2014_zpsyziio3ba.jpg.html)

You sure are shortening the odds here. :D

When working on the fuel system of a diesel you should be clinically clean, and if working the other side of the fuel filter surgically clean. ;)

[bladerunner]

You sure are shortening the odds here. :D

When working on the fuel system of a diesel you should be clinically clean, and if working the other side of the fuel filter surgically clean. ;)

thats stripping down, it got cleaned before it went back together.

[Jules]

We use 6 self tappers instead of the nails.

Note to self:
Must amend the instructions.
But also the 3 screwdriver method works for me.
Depends what width and how sharp the blades are ;)

[Tiago Silva]

Hi all,

I've read all of the topic but still got a bit confused about the LP fuel pressure:
- At the fuel filter sensor should read 3,9V and this corresponds to 2,5 or 3,5 Bar?!
- And at the rail sensor should read 1,2V while crancking and this would correspond to what pressure?
- Where should it be 2,5 Bar and 3,5 Bar?

Thank you.

[FrenchMike]

Hi all,

I've read all of the topic but still got a bit confused about the LP fuel pressure:
- At the fuel filter sensor should read 3,9V and this corresponds to 2,5 or 3,5 Bar?!
- And at the rail sensor should read 1,2V while crancking and this would correspond to what pressure?
- Where should it be 2,5 Bar and 3,5 Bar?

Thank you.

Hi ,the pressure given by the LP pumps must be around 3.5 bars
but 2.5 bars are obtain after limiter and filter IMO.

But never mind 3.9 /4 volt is the good value .

NOTHING to do with the common rail sensor which measures the High pressure

1.2volt corresponds to around 300 bars ;sufficiently to get ignition

Mike

[Tiago Silva]

Ok, Mike. Thank you. :)

[longer86]

You can also use TOAF live data feature to check fuel pressure. ;)

[FrenchMike]

You can also use TOAF live data feature to check fuel pressure. ;)

I'm afraid 6 year later that my tests are becoming obsolete now ...:D

Mike

[Tiago Silva]

I like your tests, Mike, but they revealed me a problem.

My car is having a very slugish acceleration, I mean, it doesn't rev properly, even with the foot down.

So I'm thinking MAF or Turbo problems, but a visual check on both and they seem fine. The MAF is totally clean, no residue with so ever and I disassembled the turbo and it's also in perfect condition, spins perfectly aligned and the wastegate is ok.

I tought it was the UBP, but with tour test I got 4,0v on the LP sensor at the filter, so I'm assuming that all is well with the LP line of fuel.

I did bypassed the EGR valve recently, with a kit from ebay. Could this cause this problem? I never read anibody complaining about this kind of problem after the EGR bypass, but I'm getting clueless around here!!

Any tougths on what the problem might be?!

Thank you,

[FrenchMike]

I like your tests, Mike, but they revealed me a problem.

My car is having a very slugish acceleration, I mean, it doesn't rev properly, even with the foot down.

So I'm thinking MAF or Turbo problems, but a visual check on both and they seem fine. The MAF is totally clean, no residue with so ever and I disassembled the turbo and it's also in perfect condition, spins perfectly aligned and the wastegate is ok.

I tought it was the UBP, but with tour test I got 4,0v on the LP sensor at the filter, so I'm assuming that all is well with the LP line of fuel.

I did bypassed the EGR valve recently, with a kit from ebay. Could this cause this problem? I never read anibody complaining about this kind of problem after the EGR bypass, but I'm getting clueless around here!!

Any tougths on what the problem might be?!

Thank you,

Well,have closed the little pipe coming from the vacum pump on the EGR ?

A visual check on your MAF means nothing ;better disconnect it or measure
some voltage values i had noted :shrug:
2v....2.2 at idle ;
2.5v at 2000 rpm

Mike

[Tiago Silva]

I did closed the vacum tube.

Haven't done the MAF disconected test, tough, sure am going to do it!

Thanks.

[klarzy]

Also did you securely seal the metal flexi from the exhaust manifold, leaking gasses from here will result in power loss

[longer86]

I'm afraid 6 year later that my tests are becoming obsolete now ...:D

Mike

eee technology is moving forward... sorry :D

LIVEDATA also showing MAF values

at idle generaly is about 600-700, during hard accelerating it reaches almost 1000.

I hope this will help in diagnose,
You can also check boost, without any MBC od spring modes turbo , Boost should be from 1000 to 2250
(1000 is atmoshperic pressure so 2250 is 1,25bar boost)

Low fuel pressure at idle should be 3,4/3,5 bar(mine original pierburgh fuel pump 16 years old loss a little pressure when I Hard accelerate- showing 3,2 bars and ecu reporting error with low pressure, but in tank fuel regulator is set max up to 3.6 bars)
High fuel Pressure should be about 300bars at idle, and up to 1350 when accelerating (standard values without ECU REMAPS)

[FrenchMike]

eee technology is moving forward... sorry :D

LIVEDATA also showing MAF values

at idle generaly is about 600-700, during hard accelerating it reaches almost 1000.

I hope this will help in diagnose,
You can also check boost, without any MBC od spring modes turbo , Boost should be from 1000 to 2250
(1000 is atmoshperic pressure so 2250 is 1,25bar boost)

Low fuel pressure at idle should be 3,4/3,5 bar(mine original pierburgh fuel pump 16 years old loss a little pressure when I Hard accelerate- showing 3,2 bars and ecu reporting error with low pressure, but in tank fuel regulator is set max up to 3.6 bars)
High fuel Pressure should be about 300bars at idle, and up to 1350 when accelerating (standard values without ECU REMAPS)

INVALUABLE informations :D

And opposite to T4 ,you can see them on the car in real driving !!!


I have ordred a £2 cable and i'm eager to have a play that deserves at least a donation !

"Sorry for my behavior" ???? What ? you're joking i hope ?

Mike

[Tiago Silva]

It's the MAF. I disconected and the engine started running well.

I do think that the UBP was not well too (I changed it, meanwhile) because I got the P1260 Pre-Fuel pressure error code previously and the pressure of the LP was only 2,5bar as measured with a pressure gauge.
But the problem continued, so I was getting clueless, but with the MAF test it was clear that it's not good.

Thank you all for the help! :)

[longer86]

"Sorry for my behavior" ???? What ? you're joking i hope ?

Mike

Yes I am joking, but I hope people feel better with this ;)

[FrenchMike]

Yes I am joking, but I hope people feel better with this ;)

I do prefer Maciej :D

Mike

[Jules]

I'm afraid 6 year later that my tests are becoming obsolete now ...:D

Mike

I wouldn't call them obsolete Mike
Some folk have got in a real pickle with TOAF if they don't appreciate fully how a system works.
It's not the be all and end all.

You cannot beat old fashioned fault finding techniques for understanding the whole picture.

Main agents even today will scratch their heads if the screen doesn't pinpoint a fault!!!
There just ain't the skills out there no more :shrug:

[marinabrian]

INVALUABLE informations :D

And opposite to T4 ,you can see them on the car in real driving !!!


I have ordred a £2 cable and i'm eager to have a play that deserves at least a donation !

"Sorry for my behavior" ???? What ? you're joking i hope ?

Mike

Mike of course you can see these values and indeed all of the live data when driving using T4, and for reference a healthy MAF should read between 495 and 505 mg/stroke at idle and between 620 and 680 mg/stroke at 3000RPM off load, with an engine temperature > 60 degrees Celsius, and the EGR in the closed position ;)



Readings as suggested earlier in this thread regarding MAF output are indicators of a failed MAF sensor.

Brian :D

[Arctic]

You can also use TOAF live data feature to check fuel pressure. ;)

I'm afraid 6 year later that my tests are becoming obsolete now ...:D

Mike

Hi Mike.
Not necessarily for those whom do not have Toaf or T4 and everthing helps with the prognosis, great work by the way, thank you for sharing your knowledge

[FrenchMike]

[QUOTE]]

Hi Mike.
Not necessarily for those whom do not have Toaf or T4 and ever thing helps with the prognosis, great work by the way, thank you for sharing your knowledge

Thanks Steve ,i Hope you are well ? :Ball:

Mike

[mauzao]

You can also use TOAF live data feature to check fuel pressure. ;)

I have Toaf but i don't know how to use the live data feature, what's the field to check fuel pressure and what are the expected values?

Thks

[mauzao]

You can also use TOAF live data feature to check fuel pressure. ;)

Hi there,

What fields should i read and what are the values that i should get?

Thks

Pedro

[Jules]

At idle

Low pressure 350kpa

High = 28,000 - 30,000 kpa

[mauzao]

At idle



Low pressure 350kpa



High = 28,000 - 30,000 kpaWould it be the 2 highlighted fields in the image?https://uploads.tapatalk-cdn.com/20200324/16c94b9924108c2ffd39bb6d3ee8a09a.jpg

Enviado do meu Xperia Z Ultra através do Tapatalk

[Jules]

I assume so. We use T4
Those numbers are at 2770 rpm.

You'll have to convert BAR to kpa.

The low pressure stays pretty much constant at 350kpa but the high pressure will vary from 28,000kpa while cranking to start up to around 180,000 at higher revs.

What reason are you monitoring the pressures?

[Arctic]

Hi Pedro.
Please find a photo from T4 for comparison below, it may or may not help ?

https://i.imgur.com/0kqC7uQl.jpg1

[Jules]

Yes pretty typical T4 data.

I assume that a single pump system as the low pressure figures are slightly higher?

Try turning the flash off next time:cool:

[mauzao]

I assume so. We use T4
Those numbers are at 2770 rpm.

You'll have to convert BAR to kpa.

The low pressure stays pretty much constant at 350kpa but the high pressure will vary from 28,000kpa while cranking to start up to around 180,000 at higher revs.

What reason are you monitoring the pressures?

Thks Jules, lately my car was stalling a bit when accelerating, seems like some micro fuel cut or something like that, just noticed this in low rev, when turbo kicks in, no problem.
It start's at 1st, no problem starting...
MAF is a brand new one, original Bosch.
I wanted to check if was something related with fuel pressure...

[Jules]

Do a fuel flow test 1st.

The output of the fuel filter should supply 2 ltrs per minute.
Test it into a can ;)

[mauzao]

Do a fuel flow test 1st.

The output of the fuel filter should supply 2 ltrs per minute.
Test it into a can ;)

Can i test at the fuel filter entry, right after the UBP?
At the exit of the filter it's not easy to test, since it goes right to the High Pressure system, i guess...

[Arctic]

Yes pretty typical T4 data.

I assume that a single pump system as the low pressure figures are slightly higher?

Try turning the flash off next time:cool:

HI Jules.
Hope you are keeping well in Wales my daughter is in Conwy.

Yes as opposed to one with the UBP below ;)

https://i.imgur.com/obAYqa2l.jpg1

[Teranchelope]

Fuel filter output voltage must get to 4.0v before ecu allows start up. I installed a pressure regulator oon return pipe to tank to increase back pressure to compensate for loss due to any leakback. Works fine now.

[Mike Noc]

Sounds more like you have masked an LP pressure fault rather than anything on the HP side. Given the pressure causing the leak back, you'd blow the return hoses off well before you restricted it. :eek: