My Skoda Fabia 1.4 mpi 51 plate stalled whilst waiting in traffic and now wont start. Ive checked that the spark plugs are sparking and the fuel is definently getting through as the plugs are wet from the fuel when removed. Ive also checked the oil pressure sensor (the one near the front of the engine on the passenger side). The only warning light that comes up is the oil can light which appears then bleeps but only after a prolonged turn of the key other then that it doesnt come on or stay on. My partner also turned the ignition when the car was still in gear and it jolted forward suggesting that the starter motor and the cam belt are in working order. Also i dont think the head gasket has gone as the oil and water system are free from the pollutants. Ive also checked the wires in and around the engine bay and they all seem fine.

This is killing me as i have an inkling that it me be something very simple and easy to fix well im hoping anyway.

thanks for the replies. i wouldnt say there was a rattle just general engine noise which i guess would be down to the 185000 miles on the clock would the engine stall like that if witing in traffic and is it as straight forward as just replacing the cam belt or timing chain.

THANKS AGAIN.

Edited 19 December, 201015 yr by giayney

The mpi engine uses a cam chain and is a push rod engine.

Check the compression and valve timing.

The best thing to do would be to get any codes read with VCDS. I doubt the oil pressure sensor would have anything to do with it. If the crank sensor or immobiliser had failed I do not believe the injectors would fire fuel into the cylinders. There's something unusual about only the oil warning light coming up though, I presume you mean when all the warning lights should come up before being started?

Starter motor forcing the car forwards has nothing to do with the timing chain being intact. The starter turns the flywheel which will propel the car forwards so long as the clutch is okay and engaged.

How many miles are on the clock? Was there a rattling noise from the engine?

Easy way to check if the timing chain has snapped is to take the rocker cover off and turn it over. If it turns out to be that bad someone here is after one http://briskoda.net/forums/topic/184062-fabia-14-8v-enginecrankshaft/

Edited 19 December, 201015 yr by anewman

The mpi engine uses a cam chain and is a push rod engine.

Check the compression and valve timing.

+1

Petrol engine that doesn't start checklist: Fuel, Air, Spark, Compression.

Maybe it needs some fizz ?

Edited 20 December, 201015 yr by Lew0-VRS

Thanks for all the suggestions. All very relevant and helpful. I have checked everything again.

Now I have found that the choke doesn't seem to open as I would expect it to, it's not cold and it stays firmly shut. I manually opened it and blocked it slightly open. The car will start like this but runs roughly. (I imagine that the ECU is confused, the choke can't regulate correctly the air or potentially my setting of the tappets is causing it to run badly). I can't understand what is causing the choke to stay shut I assume it is electronic but what component or sensor is defective? And does it seem likely to be my problem?

It's not a choke, cold start doesn't work like that on fuel injected engines, it's the throttle butterfly valve. Have you tried disconnecting the battery and leaving it for an hour to see if it resets the ECU?

 

If that doesn't work probably best to get the fault codes read.

Edited 11 March, 20188 yr by TMB

Throttle body adaptation required after disconnection?

14 hours ago, TMB said:

It's not a choke, cold start doesn't work like that on fuel injected engines, it's the throttle butterfly valve. Have you tried disconnecting the battery and leaving it for an hour to see if it resets the ECU?

 

If that doesn't work probably best to get the fault codes read.

Yes of course, I am afraid my experience in mechanics is a little dated. Its been many years and I am used to old drive by wire systems where you can see and operate everything by pulling the levers that are operated by wires attached to the accelerator, choke and so on.

I tried the idea of resetting the ECU by disconnecting the battery.

The car almost starts but needs some accelerator and needs a little tickling with the accelerator to keep it running. It runs a bit rough too.

A note: I found the tappet setting procedure a bit hit and miss, "adjust till the tappet stops rocking and then turn two more turns" doesn't seem very exact.

This definitely sounds like a throttle body adaptation issue.

29 minutes ago, sepulchrave said:

This definitely sounds like a throttle body adaptation issue.

Sorry but I don't understand, please can you explain a bit?

OK I googled it. It looks like a job for someone else

 

Edited 12 March, 20188 yr by PatrickHarnett
incomplete entry

The throttle body is a stepper motor with a position sensor, after a battery disconnect the ECU has 'forgotten' what position the motor was in and how much to move it to maintain a stable idle.

 

This means that software must be used to reset the calibration information so that ECU can correctly control the throttle plate.

Edited 12 March, 20188 yr by sepulchrave

5 minutes ago, PatrickHarnett said:

Sorry but I don't understand, please can you explain a bit?

 

 

5 minutes ago, sepulchrave said:

The throttle body is a stepper motor with a position sensor, after a battery disconnect the ECU has 'forgotten' what position the motor was in and how much to move it to maintain a stable idle.

 

This means that software must be used to reset the calibration information so that ECU can correctly control the throttle plate.

Thanks for your help. I'll have to find someone with the software. Its very frustrating - something so simple has become so complicated - in the past I could do everything, work it out and fix it with a coat hanger or a bit of gaffer tape!

 

I'll let you know what happens.

@PatrickHarnett check the thread below for a local member with vcds.

 

 

 

Edited 12 March, 20188 yr by bspman

5 hours ago, sepulchrave said:

The throttle body is a stepper motor with a position sensor, after a battery disconnect the ECU has 'forgotten' what position the motor was in and how much to move it to maintain a stable idle.

 

This means that software must be used to reset the calibration information so that ECU can correctly control the throttle plate.

 

Seems odd for that to happen because I've had my battery disconnected quite a few times for several hours and the throttle body still worked fine. Have also had the throttle body off to clean it and no problem either. Not saying it isn't the problem, just puzzled about it. I wonder if moving the butterfly valve has caused it.

Edited 12 March, 20188 yr by TMB

FWIW it's not a stepper motor in the throttle body, it's just a two-wire dc motor. There are two opposite-sense potentiometers that do the throttle position sensing. I think if one moves the butterfly by hand, it just springs back to where it was after you let go, can't see that causing trouble unless you were really brutal and managed to damage a gear within the reduction mechanism.

 

All 6 wires (two for motor, four for pots) seem to go direct to the ECU on your engine @PatrickHarnett, so it may be a case of using a test meter to make sure there's continuity in all 6 (can specify pin numbers for you if you want to try this). Certainly a visual inspection of the TB connector and wires emerging from it would be a good plan.

 

 

I had to re-adapt mine after removing the throttle body on my 1.4 16V to strip and clean the entire inlet manifold, the car would not start and run until I did so, it would just die.

 

Which is why I mentioned it.