Poor running 7A (in my cabriolet)

[quattrostyle]

Been mailing back and forth with Steve who came with things to check and lots of usefull info. I put the old o-rings back on the recently purchased injectors and now it's leak free again. So now the FPR and injectors have also been changed, making zero difference.
What also makes zero difference is the following:
- removing vacuum line from the FPR (you can feel there is vacuum in the line though)

- removing throttle potmeter connector

- removing lambda connectors

The above doesn't have a single effect on the engine running, not on idle, not on part or full throttle.

Made an appointment with an Audi mechanic who is very good with these old Audi's but it will be another two weeks before I can take it there. So any tips in the meantime are welcome.

[quattrostyle]

Update from the specialist my car is at now:
- resistor for the injectors wired or connected incorrectly
- lambda probe ground not connected under the dash
- bad connection/wire somewhere near the throttle body
- throttle body potentiometer not functioning
- one knock sensor defect
- lambda probe is slow but still works at the moment

So took the throttle body incl. potentiometer to him that I had removed in the hope it is good after all and also the spare knock sensors incl. the ones that I removed from the engine. According to him it is more awake above the 4k rpm already due to connecting the resistor correctly and fixing the other issues. Should have it back somewhere next week

If my spare potentiometer is broken as well, are they available somewhere?

[Henkjan]

it's probably a Bosch part, so any Bosch car part dealer should be able to sell you a new one

[steve briance]

Is your potentiometer 3 pin or 4 pin?

[steve briance]

Good to hear there is some progress - the guy has found a good list of problems, once they are done it stands a good chance of running properly! Sounds like it was never running right if things were just not connected. Looking forward to an update :-)

[quattrostyle]

Is your potentiometer 3 pin or 4 pin?

4 pin from memory, don't have the car or the potmeter here now so can't check the part number. Expecting a call any day now and then I'll know if anew one is needed.

[steve briance]

If you need one, I have a 4 pin throttle potentiometer which I will never use as mine is 3 pin. Let me know and I will check the resistance figures and if good, you can have it for a good price :-)

[quattrostyle]

That would have been good mate, however thursday I got a call that the spare potentiometer was also bad, but another throttle body with good one was found the same day locally. Should have the car back somewere today.
That being said, it's still worth it to check your spare potentiometer as they are hard to find in good shape and I have two spare throttle bodies with a bad potentiometer.

[Henkjan]

why not put in a new potmeter? replacing dodgy instruments that died of old age with stuff of the same age is something I gave up long ago.

[quattrostyle]

And where exactly does one find a new Hitachi potmeter?

[Henkjan]

in my area, http://www.hoflandbv.nl/ would be a good bet...

[quattrostyle]

I would be surprised if they have it, but can always try I guess.
However the car is back now and running a lot better

[quattrostyle]

Well my spare throttle body had a bad TPS also, so a good second hand was found the same day. Got the car back a week ago and noticed some hesitation on the second test drive I made which turned out to be a bad spark plug wire. Now it's finally running right and the summer is officially gone cleaned the car thoroughly and put it up for sale yesterday: https://suchen.mobile.de/fahrzeuge/d...0&vc=Car&dam=0