1.8T starting /restart problem

[richyl]

Hi, hope someone can give me a steer on this one .
Fuel pump failed a couple of years back so replaced it with good used one and fitted the FOC .Haven’t used the car much since . Got it on the road recently and had fuel pressure dropping off.
Replaced the pump with a brand new one and also replaced the fuel filter in case of stale petrol. All petrol drained and replaced.
The car will start with fuel pressure about 50. However , if you turn the car off it will not restart and no buzzing from the pump on turning the key to pos2.
Fuel pressure gauge reading is very low , leave it for 30 mins snd it usually restarts .
RAC recovered it about a week ago before the pump was changed as it just stopped and wouldn’t restart.
By the time they got there it decided it was ready to restart , no fault code on their reader. There was 2 of them so they drove it back 5 miles and said it drives lovely! Still no codes.
Im at a loss where to go next, any help would be appreciated. Cheers Rich


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[cat]

I'm far from qualified but it could be a sensor. Crankshaft or camshaft? Unrelated to the fuel pump. I think I've read about this before, not sure which engine so maybe talking nonsense. Do a search of the site. Hopefully someone who knows what they are talking about will answer.

[SD1too]

Originally Posted by richyl

.. if you turn the car off it will not restart and no buzzing from the pump on turning the key to pos2.

By "pos 2" I take it that you mean "ignition on".
Is the pump silent when you do this on a cold engine?
I'd suggest lifting the rear seat cushion, placing your multimeter across the pump power supply and waiting for the fault to manifest itself. On turning on the ignition you should see 12v for two seconds. On cranking, you should see 12v continuously.

Simon

[mbonwick]

As others have said, this sounds more like a failing crankshaft sensor rather than a fuel supply issue.

There is by design a time delay before the pump will reprime with the ignition on - so its not suspicious that you're not hearing it when trying to restart.


Crankshaft sensors are known to start playing up when hot, before completely failing. Does the tacho (rev gauge) move when it's cranking but not starting?

[richyl]

Originally Posted by mbonwick

As others have said, this sounds more like a failing crankshaft sensor rather than a fuel supply issue.

There is by design a time delay before the pump will reprime with the ignition on - so its not suspicious that you're not hearing it when trying to restart.


Crankshaft sensors are known to start playing up when hot, before completely failing. Does the tacho (rev gauge) move when it's cranking but not starting?

Hi all,
Thanks for all the advise, car has been starting ok for a few days haven't driven it around though. I had ordered up a crankshaft sensor so I changed it today.Worse now won't start at all. The rev counter is not moving when cranking and not starting.
Any ideas.
Thanks
Rich

[Yorkshire GOC]

When the Rev counter does not flicker thats a classic symptom of a duff crank sensor - i always go for a Siemens Crank sensor you may have a dud

The absence of movement on the rev counter when you crank her is because the crank sensor is not sending signals to the ECU. Is it connected snugly.

[richyl]

Originally Posted by Yorkshire GOC

When the Rev counter does not flicker thats a classic symptom of a duff crank sensor - i always go for a Siemens Crank sensor you may have a dud

The absence of movement on the rev counter when you crank her is because the crank sensor is not sending signals to the ECU. Is it connected snugly.

I have replaced the new one with the old one which started the car this morning. Same issue now,no movement on rev counter. I Looked online and some of these sensors come with loom YSB114000 . I traced my harness back thinking it may be the wiring and it goes straight into the main loom of the engine. Im sure I've seen somewhere what voltage you should get at the plug but cant find that information now.
Im thinking should i cut it off and solder in that loom.
Sorry to be a pain everyone .

[dave lincs]

If it started before you changed the sensor now it wont then change sensor back again and try also check the wiring that goes to it the can get brittle and break

[COLVERT]

Originally Posted by richyl

I have replaced the new one with the old one which started the car this morning. Same issue now, no movement on rev counter. I Looked online and some of these sensors come with loom YSB114000 . I traced my harness back thinking it may be the wiring and it goes straight into the main loom of the engine. I'm sure I've seen somewhere what voltage you should get at the plug but cant find that information now.
I'm thinking should I cut it off and solder in that loom.
Sorry to be a pain everyone .

You are NOT being a pain.--This forum is all about helping members to fix their car problems.

[richyl]

Hi all ,
Thanks for your help so far. Ive done some checks on the wiring.
I have stripped back the insulation on the 3 wires going to the crankshaft sensor and connected a meter between this bare section of loom and the plug pins this is what I've found.
Looking at the plug with the release clip on the top blue/brown left Pin. Purple/Blue centre pin and pink/blue right pin.
Left pin bl/br give continuity on correct pin and the right pin.
Centre pin pu/bl gives continuity on correct pin and right pin.
Right pin pk/bl gives continuity on the correct pin only.
I don't have a wiring diagram and electrics are not my specialist subject. Any advice before i buy the replacement loom YSB11400.
Thanks again
Rich