Both fuel pumps not working!

[kamylion]

Hello all,

My 2002 mg zt-t cdti has been running well until now.
It doesn't start and i cant hear neither of the pumps (ubp and itp)
What could it be?

Both pumps were done and all injectors refurbished last year.

The ecu hasn't any signs of water damage.
Is there a fuse or relay for the pumps I can check.
Just bought a multimeter but not sure how to use it as there's no instructions.

Any help much appreciated.

Have now realised itp is working but ubp isn't.

[ninaandphil]

When you say you can't hear the pumps running, have you lifted up the rear passenger seat, drivers side, and had a good listen? When you turn the ignition on you should hear it running easily until it has primed the system a few secs later.....
The front one is much quieter, I can't hear mine on my cdti, to check it's running and sending fuel to the rails, you can unclip the fuel pipe, rail side, put some rags under, and turn on the ignition, fuel should be pumped through.
If no noise from the rear pump, then it's most likely failed.
My rear pump failed recently, but I changed both, as if the rear fails, the front can keep the engine going for a while if there's sufficient fuel in the tank and it can lift it, put it puts a strain on the UBP and can trigger it to fail as well...
Good luck, many experts on here can advise, I'm an amateur!
Phil

[klarzy]

Fuse 28 (30A)
Relay 103

both in passenger fuse box

[Mike Noc]

Does the oil light come on with key to position II before you start cranking the engine?

[marinabrian]

Have a look HERE (http://www.the75andztclub.co.uk/forum/showthread.php?t=151357&highlight=doctor)

Failing that, I can test/repair your ECM.

Let me know how you get on ;)

Brian :D

[kamylion]

Sorry to be a pain but turns out the in tank pump is humming away and ubp is defo not. tried listening to itp through filler cap because work tools were on back but have just moved it all and can hear it.

Fuse 28 was for the horn, can't see relay 103.

Just had RAC out and they said it was one of 2 things, either the rail pressure sensor or high pressure pump.
He said hope its the sensor or it'll be very costly :(

He had his computer hooked up showing there was no presure in the system, Does that all sound right?

[Greeners]

you need to check you've got 12v at the UBP....

[klarzy]

Sorry to be a pain but turns out the in tank pump is humming away and ubp is defo not. tried listening to itp through filler cap because work tools were on back but have just moved it all and can here it.

Fuse 28 was for the horn, can't see relay 103.

Just had RAC out and they said it was one of 2 things, either the rail pressure sensor or high pressure pump.
He said hope its the sensor or it'll be very costly :(

He had his computer hooked up showing there was no presure in the system, Does that all sound right?

pull the plug out of the UBP a couple of times and see if it kicks in to life...

maybe just a bad connection...

there would be no high pressure if the engine is not running, the high pressure pump is driven by the engine...??

[kamylion]

Oh......

Ok I'll go jiggle the plug about a mo,ta.

[kamylion]

Just had another poke and prod but still no joy :(

[Greeners]

Just had another poke and prod but still no joy :(

You need to see if you've got 12v ...either with a meter or a test lamp

[Davy]

Try turning the ignition to position 2 and then tap the under bonnet pump with a spanner or screwdriver and it may work temporarily. If it does it will need replaced

Davy

[Mike Noc]

Just had RAC out and they said it was one of 2 things, either the rail pressure sensor or high pressure pump.
He said hope its the sensor or it'll be very costly :(

He had his computer hooked up showing there was no presure in the system, Does that all sound right?

Nope sounds pretty much completely wrong. :getmecoat:

If the UBP isn't running you won't have any pressure in the system and that isn't anything to do with either the rail sensor or HP pump. :duh:

Try giving the UBP a tap - they often fail to start when worn. Both ITP and UBP pumps are fed by the same relay, so failing broken cables and dodgy connections, if one is working the other one should be.

PS I see Davy beat me to it. Must learn to type faster.

[kamylion]

You need to see if you've got 12v ...either with a meter or a test lamp

Sorry 12v on what?

I've tried tapping the ubp but nothing. I'll pop out once more though....

[Greeners]

the plug on the UBP

[Greeners]

if you have no power there, then it'll never start

[klarzy]

do you need to remember to turn the key off and on again as the pump only runs for 40 seconds or so ??

[kamylion]

Just hit it some more and there's no life in ubp.
Can't possibly be broke as its only done 2000 miles!

[klarzy]

turn the key to O then to II again and re tap it... or meter the cables to see you have 12v as suggested...

[Greeners]

Just hit it some more and there's no life in ubp.
Can't possibly be broke as its only done 2000 miles!

You can knock nine bales of **** out of it, if there's no power to the plug it'll never run.....!!!

[marinabrian]

Add this into your actual fault finding, and disregard everything the RAC man told you.

Firstly, unplug the electrical connector to the UBP, now have a listen to the ITP, many people often mistake the return fuel flowing into the tank for a working ITP.

Secondly how much fuel do you have in the tank?

With your new multimeter check to see If you have 12 volts between the black wire and the white/purple wire.

Injector operation is inhibited by the ECM if it sees a low pressure rail sensor reading of less than 121 Kpa, around 17 1/2 PSI.

I suspect if communication was entered into with the ECM with his diagnostic equipment, then the ECM is at least powering the main relay.

So I will allow you to continue your checks, and my offer of testing your ECM still stands ;)

Brian :D

[kamylion]

do you need to remember to turn the key off and on again as the pump only runs for 40 seconds or so ??

:eek: Cheeky ******,
I know that :whip:

[kamylion]

Unplugged ubp and had a listen, itp is definitely humming/buzzing away.

It has half a tank of fuel.

Providing I did the multimeter test correctly it was showing 11.08v
What section do I put it in, there's about 4 I think?
V~, A- with 3 dots under the line, ohm symbol or V- with 3 dots under the line??
For the 11.08 it was the latter.

[klarzy]

The latter is DC volts and correct

[kamylion]

Um... I've just sent a report by accident instead of pushing the reply button without thinking, have I done something bad?

What I was going to say was, do you know what could be causing the voltage to be 11.08 instead of 12v?

[Dragrad]

Um... I've just sent a report by accident instead of pushing the reply button without thinking, have I done something bad?

No harm done :D

[Phil-T4]

11.08 is relative to your battery voltage minus a small loss due to wiring and relays, it is however enough to run the pump.

If you have voltage at the connector but the pump isn't running then the UBP has failed.

[steve811]

I have a spare UBP here, and it's yours if you need it, PM me if I can help.

[kamylion]

Ok thank you all for your help, I'll email dmgrs and ask for a replacement as it was only fitted 3 months ago.

[Stickman]

Shame you weren't nearer m8 else you could have tried another ubp
I have a spare one :D
Regards
Chris

[kamylion]

Just done some volt readings trying to follow this thread http://www.the75andztclub.co.uk/forum/showthread.php?t=69308 ,
does this all seem ok?

These are on the V- with 3 dots underneath the line and turned to 20 and all taken with key on position 2.

Car battery now at 11.89
Low pressure is 4.99
High pressure is 4.99
Plug on top of ubp is 11.66
Cam sensor is 11.66

Also just a reminder that the in tank pump is working but not the ubp.

[kamylion]

Also just noticed that it appears that fuel is coming up into the electrical plug on top of the ubp, is that normal?

[Greeners]

nope......i suspect it's failed

[Mike Noc]

Also just noticed that it appears that fuel is coming up into the electrical plug on top of the ubp, is that normal?

As David says it certainly isn't. This has been seen before with some cheap pattern pumps.

Good job you spotted it as, given enough time, diesel will track down inside the cable insulation and soak the cabin fusebox. :getmecoat:










.

[kamylion]

Oh........ I did notice a drizzle mark on the sponge on inside of cabin fuse box cover too, didn't know what it could be so that'll be that then :(

[kamylion]

A big thank you to Steve811 for letting me buy your spare ubp last night :D

Turns out the fault was the pump like you all told me, now it's running good again :D

[steve811]

Glad you got it sorted!

[Falcon Flyer]

Good news! A cheap fix!

Forum: 1, RAC: 0 :D