V6 cabriolet odd injector problem

[220bhp]

My wife's 2.6 ABC cabriolet is still running poorly. The current symptom is that it starts and then stops straight away. After three of four times it runs, sometimes on all six sometimes not. On the road it seems to run fine even better if you drive it hard, which she never dos. It smells a bit rich on tick over. Had a mechanic look at it the other day
tried to read the codes but did not have the right cable . This has been tried before but for some unknown reason the ECU will not give up the codes. However we did find two things, one some corrosion in parts of the fuse box. the other strange thing when trying to find which cylinder was playing up we pulled the injectors of one at a time. The drivers side where all ok. The passenger side was very odd we could not determine which one made the difference, first it was the front then the back then the middle.
Then it started to idle well for a while then lumpy, took all three of and no difference.
Put them on again and it ran smooth. I have changed just about every thing on the car.
All the electrics plugs fuel filter FPR plugs and isv Two different sets of injectors.All improve things a little but this starting issue is getting worse.
If anyone has any ideas please let me know .it would be much appreciated.

[caterpillar]

check out the thin plastic tubin for the diesel; it might have some leak issuse ... from the tank to the pump.... have a really close look from the tank armateur....spec on the suctions side..

[quattrostyle]

This will be a petrol not a diesel..

[newsh]

How about trying to read the blink codes? You should be able to do this with a short bit of wire and an LED. Does the fuse box have the black white and blue 2 pin plugs?

It seems like all 3 injectors are getting a bad signal on the same bank, maybe they share a fuse? I think the injectors are powered all the time the engine is running and grounded by the ECU so the common thing would be the power feed to that bank. Could be a corroded wire or connection or fuse if there are separate fuses for the 2 banks.

Does this engine have a bundle of brown ground cables boltred to the engine somewhere?

[220bhp]

John do you mean the earth wires like on the s2, if so yes there are, and I will give them a clean. I have tried to blink the codes with no success. Dan {coupewannabes2}
has offered to have a go with vag com.

[220bhp]

I have cleaned up all the earth wires I can find.Removed and cleaned the IAC valve. checked the plugs, which where a good grey to brown colour. Cleaned the breather pipes from the rocker cover to the throttle body, also cleaned the cover. Checked and cleaned up the fuses and there was some rust on the intermittent relay ,but the rest where clean. remove the motor fuse for 30 minutes. All that and the start stop problem is still there.
It takes four or five times before it starts, hot or cold, but when it dos start it runs a little smoother, so not a complete waste of time.

[220bhp]

Plugged the car into vagcom tonight and got two codes 00554 lamda lower limit intermittent, And 17979 see other version, whatever that means. maybe someone can help with that one.

[Monkeymagic]

17979 is left engine mount solenoid. DOnt worry about it.

[220bhp]

My mistake the code was 17978 . Just found out its an immobiliser problems.
Symptoms are very much as described . I did find another ecu, but the car would not start when we swapped it over. I have since found out that it has to be recoded. I am not sure if that is correct or not. If it is how would I go about this, and what would it cost.

[220bhp]

[mike74]

you might have to direct to Audi or a specialist to get new coded keys created for that ECU. There's various company's on t'internet that can do it but not sure of the costs...probably waaay cheaper than the stealers though!

[CoupeWannabeS2]

Hey again Lou,

Just thinking around the issues on the cabby, and in connection with the immobiliser fault code we pulled.

I figured it might be trying the spare key for the car. My logic being that if there is a problem with the immobiliser circuit in the key, perhaps the spare will work.

Could well be a long shot, but as its easy to try I thought it worth mentioning.

If that doesnt work, my other thought was if there is a problem with another part of the immobiliser system, are there any other ECU's available for the 2.6 cabby that don't have the immobiliser circuits in it? Someone with more knowledge might like to comment, but my car has a different ECU in it that doesn't recognise the immobiliser system on my car.

The key I use doesn't have the immobiliser circuit in it, and although the car knows this (as it flashes its immobiliser light on the dash) the ECU doesn't cut the ignition and the car runs fine. Hope that makes sense.

Did you manage to get some replacement Lambda sensors from the breakers yard?

[220bhp]

Dan I haven't changed the lamda.s yet, but it was the spare key we where using on Wednesday. I also fitted another ecu on my coupe when I was having problems and there where no issues, it started and ran ok., but when I fitted another ecu into the cabby it refused to start at all. Have you tried your vagcom out on your car to see if it works.

[CoupeWannabeS2]

So its probably not the key then.

It looks like the codes we pulled off of the car came up after a couple of days - as you had pulled the fuse to clear the fault code memory a couple of days before. I wonder if there are two separate issues - the running possibly due to Lambda's, and the starting due to an immobiliser issue.

I note that you have tried a different ECU already, but wondered if anyone else knows if there is a particular part number for an ECU that would work in the car that doesn't have an immobiliser circuit in it.

From memory the ECU's for an S2 have a part number that ends in an A or B or C, these letters denote if the ECU have an immobiliser in it or not. I wonder if the replacement ECU you tried was one that has immobiliser circuits in it.

In relation to VAGCOM, I think I may have fried my lead as I think I plugged the 2x2 lead in the wrong way round at one point. I couldn't get it to work on my car or the wifes Passat the next day. I have got another lead on order from ebay so hopefully will be fault code reading again soon.