This car is a non quattro. It is 4 cyl. It runs like crap when its cold...I have to keep gassing it to keep it running. When its finally warm, it idles up and down 1200-900-1200-900 back and forth...I replaced the air idle unit and it still does this but when i disconnect the plug on the back it runs smoothly...when warm...Its still hard to start though..even if warm...Where do i go from here? I sprayed starter fluid all over the vac hoses and there does not appear to be a vac leak. Maybe an o2 sensor? maybe a heat sensor? PLEASE HELP IM SO PISSED!!!

Thanks

Dan

1990 Audi 80

 

Hey don't get mad...I have been where you are....I had an older VW that would do what youare talking about the fact that it starts at all tells me that it is not the o2 sensor, but if you were to look into your book under warm up valves or regulators...I think that you would find your problem.... On the older Audis and Vw's they actually had a temperature unit on the side of the engine...but I have not had any thing that was newer than an 86...so your might be alittle different but not by much...Take a look at your book and look up the warm up circuit you will more than likely find it...Let me know if you don't have a book and I will see of I can find a site that has the diagram, and guide..for yours...It is going to run great again....

 

Thanks for your reply. I do not have a book, nor can i find one. I want a bentley manual which is what i have for my triumph. Anyways...If you can help me id appreciate it. I noticed 2 plugs going into and area where it seems a temp reading could be taken. Anyways, one is plugged in...the other is 2 wires dangling near it. I hooked them up and nothing. Anyhow, im going to the junkyard tomorrow to find some bits and pieces...any idea what this warm up circuit or valve looks like so i can find it? Thanks!

Dan

 

Ok so it is a Audi 80 it it Turbo???? I will look around and forward you the link to the site...

 

This is one of the sites that everyone uses here... Use the search and find the technical data...

http://www.sjmautotechnik.com/troubl...ing/ficis.html

 

Ok now that I have seen the type of system it is, you will have a 5th injector that is located on the intake plenum oposite from the throttle intake...It is held in by two screws, pull it out and see if it is clogged or not pushing out the fuel in a regulated pattern, this will be controled by the thermal sensors...that are on the head and in the neck of the outlet on the engine head..if either of these are not operational the venicle will do basically what is happening to you...Check your junk yard and find an 80 that is hit. not a perfect one but one that was running at the inpact...get these sensors then try them...if it works then go and by the new ones...

 

OK,

so after a good weekend of wrenching on the audi 80, non turbo...here is what i have done. Replaced fuel filter, knock sensor, cold start valve, fuel pressure regulator, idle air valve. All parts were pulled from a 90 audi 90 but part numbers matched.

Here is what i concluded. The car now runs MUCH BETTER. However...I have to run the car with the idle air control valve disconnected to get it to run right. IF i conect it, i get the rev, drop rev drop thing. Also...when the two wires are connected to one of the temp sensor (the one sensor that reads something ;like 120 degrees celcius) the car has NO HIGH END POWER and is very weak. When i disconnect from this sensor, the car runs fine..when warm of course. I replaced this sensor with a 80 Degree celcius sensor from the 90 and it runs poorly again. I have the piece disconnected. Also...I got the rear plate lights to work but still not the instrument cluster. I replaced the instrument cluster with one from a 90 and it still has no lights. Also, i checked all trunk wiring and can see no visible damage to the wires even with the sheath removed. Anyway, back to the cold stasrt problem...I will check the injector. I also have a good idle air control valve coming in from ebay i will try. It just irritates me that when it wont cold start without the wire plugged into the back of the idle air control valve. but with it plugged in, it also fluctuates RPM like crazy. Thanks again for all your guys help

Dan

1990 Audi 80 Series

 

OK so it sounds like you have a vaccume leak...take a look around the intake and make sure there are no holes worn on any of the hoses...Then get some carb cleaner and spray the manifold with the engine running. If it fluctuates when you spray the manifold then look for more vac leaks...

 

I have sprayed starter fluid all over the place and no fluctuation. What do you make of the fact that the one temp switch makes the car run poorly when hooked up? When un hooked it runs fine. does this need to be hooked up?

Dan

 

means that sensor is bad, was this one of the ones you replaced?