I just bought this car.

1991 Audi 80 , auto , FWD , 2.3l 5 cylinder.

I have worked on ALOT of VW but this is my 1st Audi.

Car will not catch while turning over.
When it does catch I have to baby the throttle to keep it from dying and while Im babying the throttle it sounds like its running rich and smells rich.

It will catch , with help, like every 1 out 20 trys.

The PO had cut the ground wire off the cold start injector and ran it inside the car so he could manually ground out the cold start injector when trying to start the car.

That is how He got it started for me to test drive.
It drove great once it got started.

Where is the Coolant temprature sensor?
Also what is inline , electrically , before the cold start injector?
I need to test why the cold start injector isnt shutting down after it starts, or is it not suppose to shut down after start?

 

The engine temperature sensor should be located on the engine block next to the upper radiator hose and looks like:
[IMG]local://upfiles/1095/F2906B03D63044468E16F3AD4E1AA2A2.jpg[/IMG]
The cold start injector should only work when the starter is cranking. If it is ON all the time then you have a wiring problem. I will have to look at my manual as I believe it is the same as on my 91 100Q.

 

Heres what the starting scenario is at the moment.
I have reattached the wireing to the Cold start valve and checked for voltage @ the cols start inj. and it was good.
This resulted in the same non start issue.
I then found the CTS and disconnected it .
The car would then start , rpms would climb to about 1200 and then dye out, and the car would die.
I can hold the rpms up with the foot pedal but as soon as I let go of the pedal it dies out.

I believe the Cold start valve is going continuously and that is the reason for the non start and flooding issue.

I also found 2 extra cold start inj in the trunk and a fuel dist assembly.
Also the fuse relay box under the wiper cover was open and there were 2 extra fuse relays floating around in the wiper cowl.
They were obviously dealing with the same issue.

How do I , if I can , retrieve any codes ?
Or does this car not have a way to do that without a VAG?

 

After going out to the garage and doing somemore trouble shooting I found out the following new things.

1st - I disconnected the CTS and then went and started the car .
it started , I had to throttle it alittle and hold the idle @ around 2500 for about 30 sec.
then it held its own idle , at around 2500 rpm.
Then , while the car was running, I went to investigate the high idle and noticed the throttle stop screw was WAY tightened down .
Allowing the throttle to not folly close.
I unscrewed the throttle screw till I got the RPMs around 1000 and then shut the car off.
plugged the CTS back in and then tried to start the car.
NO start.
Unplugged CTS.
Car started back up.
Weird.
So I turned it off .
I suspected at this point that maybe the throttlw wasnt hitting the idle switch.
Sure enough it wasnt.
Adjusted that.
Turned the key .
car started but barely held an idle, turned car off.
Suspected ISV.
checked for voltage to ISV , good.
checked for operation of ISV via plugging into another + source, worked, opened and closed.
But no operation while connected to the factory harness.(weird)

So I know this much.
Bad CTS.
Bad electrical connection at the ISV or Corroded connection.

 

Check and clean the connectors and ground points. That is the first thing I always recommend that people do when they have a vehicle that is 10+ years old. I have seen too many connectors and not just on Audi's that go bad or have the wire break right at the crimp. You can check the CTS with an ohmmeter, for exact values you will need a chart, as it is obviously temperature dependent. You can simulate cold and hot conditions by plugging resistors directly into the connector.

 

I am going to clean the ISV terminals with some electronics cleaner.
Has worked well in the past on all the VW I have worked on.
As far as testing the CTS with a ohmeter.
I have a meter , just dont know how to use it yet, its analog.
I also dont have my Bentley yet, in the mail, so I dont know the procedure.
Im just gonna buy one for $30-40 so that I can take it out of the scenario.

 

You can use an analog meter for checking the sensor by itself but don't try to read the voltage from the connector. I think the resistance range should be the same as in the VW models. Probe lengths and threads vary but I think that the resistor itself is the same. It should be about 5K cold and about 200 ohms hot.

Check the throttle switch for electrical functioning, just because it “clicks� doesn’t mean that it works.

 

Cool , my bentley just arrived.
My wife and 3 yr old son are gone this weekend so Ill have lots of time to get this bugger runnin.
As long as I dont run into any parts that have to be special ordered.
More than likely I will have special order parts, boo hoo, LOL.

I was thinking the same thing about the idle switch.

Im sure there is a procedure in the bentley for testing it.

Is there always voltage @ the electrical harness for the ISV when the ignition is on?

 

Replaced CTS = no luck , still no start.

Got my bentley today and am goin to build vag test lite, so I can check codes.