Audi 80 coupe 2.6 v6 running issues

[bagpipingandy]

Hi all,

i have a Audi 80 V6 2.6 1996 with running issues,

the problem is when warm on tickover it idles very irratically and is undriveable when reving, it coughs and splutters and ussually stops,

however it seems to do this intermittantly, like today it rus ok and seems to only happen when it is warm after 30-40mins

i have VAG COM and read fault codes a few days ago and had some faults, i cleared them and after running poorly today there are no fault codes,

i have started from scratch fault finding, i have a spark on all 6 cylinders, injectors squirting fuel OK, no obvious air leaks, plugs look ok in colour, perhaps smell of fuel which would suggest lack of air, so i am thinking is the choke sticking on once warm? 1st is there a choke and where is the choke?? i took a few plugs off and removed an actuator of sorts from the air intake/throttle housing but made no difference, the car starts but runs very rough coughing and the odd backfire then ussually stallls after 8-10 seconds.

then went looking for the fuel pump but i do not know where it is can any one help with its location? i see the fuel lines come out the floor pan and through the filter under the car but no obvious fuel pump,

It's getting fuel through the injectors and it starts so i am thinking , choke or even could the exhaust/CAT be choked and also causing the issue?

I will try the car cold again tomorrow but I would appreciate some ideas what to try next?

i await any of your suggestions,

best regards

Andy

[zollaf]

did you make a note of the fault codes that were stored. its just that with an intermittant fault it sometimes takes a while for it to be stored, so although you have erased them and nothing has come back, it could just not have been stored again yet.

[zollaf]

have a look at the same problem as yours, in the vag com section. relay 30 could be your problem as well.
thats you as well, im confused now?

[bagpipingandy]

Yes that is me that was the original Faults found,

as below:
Address 01: Engine
Control Module Part Number: 4A0 907 473 D
Component and/or Version: 2,6l V6 MPFI HS D05
Software Coding: 00062
Work Shop Code: WSC 06317
2 Faults Found:
17978 - Engine Start Blocked by Immobilizer
P1570 - 35-10 - - - Intermittent
00575 - Intake Manifold Pressure
04-10 - Mechanical Malfunction - Intermittent
Readiness: N/A

i posted this in the Vag com section for some ideas, then the car run fine until this week when now it is stuck on my driveway running rough. the intake manifold pressure came back last night, is there a MAF on this car and where the heck is it!! it is not obvious in the intake piping!!

But i also like this relay 30 idea, Where will i find relay 30?

any info once again greatly appreciated

[TA8535]

we have an 2.6 80 avant the fuel pump is in the tank methinks presume the same on yrs

patrick auckland nz

[bagpipingandy]

Update on the Audi 80 Running issues,

I cannot find relay 30 and doubt if i even have it!!

any idea if the 2.6 V6 has one??
I looked under steering coloumb, there are relays but none powering the ECU, also checked the passanger footwell (UK CAR) no relays there, and none under the bonnet in the fuse box Either.

car running fine just now but i haven't changed anything, i know it will come back if i run it for a while,

next question is is there a MAf sensor or where is ths intake manifold pressure sensor??

this was logged ,as above, again on the VCDS today

any info greatly appreciated

Andy

[jamiecoysh]

the ecu is probably under the back seat and it sounds like ya oxygen sender is faulty

[towcestervag]

you engine ecu is located behind glove box on bulkhead
there is no maf sensor as such
the inlet manifol pressure sensor is mounted near throttle body?