ABK Engine 2.0 Coupe April 1996 - Starting

[JASPER6BEARS]

Hello

We have a 2.0 8 Valve Audi coupe April 1996 on log book engine number starts ABK

It will start about every fifth time and run fine.
Other than that it fires then dies straight away.

Once its running for 5 seconds or more, it does not miss a beat and never cuts out or stalls.

An Auto electrician had it for 2 weeks and could not solve it?

He said he tried ignition wiring, distributor, ECU and ignitor box.

If he had I am not sure!!

Any clues out there - the so called electrician also said the diagnostic machine he has did not help him?

Any help would be great.

Thanks Tim (Surrey)

[a8 tech]

Check the fuel pressure and the condition of the fuel filter.Audi say the fuel filter isnt a service item but its been on a while and it needs replacing.Also consider the fuel pump

[JASPER6BEARS]

Thanks

Wouldn't problems with the fuel filter/pump give other running symptoms also?

Thanks Tim

[a8 tech]

Well if you have a holding pressure drop you will have to crank it more to pull the fuel up so it makes sense that if you disconnect the fuel pipe when cranking and see if you have fuel delivary to eliminate from your diagnosis and also never say never.The hall sender for the dizzy is the old favorite on the ignition side but it seems the electrical side has been tested.There are measured values you can look at with vag com to lift some light on your problem but there aint much.

[JASPER6BEARS]

Cheers

[JASPER6BEARS]

Hello Again

More on the Audi coupe 2.0 8v ABK starting problem.

2nd electrician used diagnostics and got a readout of speed sensor fault.

Would this cause a start and die seconds later fault?

He says its on the gearbox is that correct.

Any comments would be great.

Thanks

[a8 tech]

If the screen protective loom is damaged then yes as a high resistance would be recorded.Implausible signal.The only way to confirm this is to scope the sender and watch for irregular patterns or on off time of sender.If this is gobbldy gook refer to your electrician and he should be able to confirm.Or a simple resistance test of the sender with a multimeter should be fine.There is still a possibility of fuel delivary as the sender will still throw a fault if the vehicle is turning over for longer than expected from fuel starvation.When the vehicle starts then the sporadic nature of the fault will clear.

[mastertech]

Sounds like an immobilizer fault to me-- is the immo light flashing when it fails to start. Thats if its got immo--think 1996 80/coupe had then diag address25 separate unit usally small white ECU up near clutch pedal

[a8 tech]

No mention of fault codes in 25 only g28 in 01.But still worth looking at.Jasper i would recommend the auto spark checks the key recognition via vag com or what ever he is using.

[a8 tech]

You could connect some clear fuel pipe onto the supply pipe and a mutimeter at the distributor pins 1 and three.When the fault occurs look for voltage droping off and fuel flow in the pipe also connect led to pin two of the dissy and check you have a pulse signal.This will help eliminate ignition or fuel.If i am wrong iam sorry but iam going off memory and trying to reduce your time spent on the fault finding.