Just as the title says, I got this 88 Audi 80 that I discovered won't start in the cold. It cranks and tries to kick over once, but is not successful in starting. Sounds like it's cranking normally. Alternator and battery are new. Plugs are fine, just regapped them even. Same problem. Where should I start? Not familiar at all with this CIS-E system. Looks complicated.

 

Actually cis is quite simple. Things to check for however before you get to the fuel system. Make sure you have spark...pull a plug, reconnect it to the wire and hold it by the rubber covering. turn the engine over while holding that plug near the block (or simply set it on the block) and you should see a spark jump when a friend turns the engine over.

NOW we can get to the fuel system...if you do have spark. My bet is that either your cold start injector isn't working, you auxilary air valve isn't opening or your warm up regulator(fuel pressure regulator) isn't working. You could also simply have a vacuum leak. The simple thing to check for is vacuum leaks. To do this grap a can of starting fluid. Now as your friend is turning the engine over spray into the intake so at lease the engine starts. Once you have it idling well then we can do this test. when it is at a steady idle, spray a bit around each of the injectors, the seam between the intake manifold and the head, each of the vacuum lines and the pipe between the throttle body and the airbox. It at any point the idle goes up as you're spraying then you've found a vacuum leak. FIX IT! A vacuum leak can wreak havoc on this fuel system.

Oh yes and there is also the vacuum valve to consider. It looks like this.... The manual can guide on how to check that its working correctly as I have never had to deal with one of these.

The cold start injecter is the 6th injector that give the engine a spurt of fuel when the engine is cold so that it can start initially. The way to test it is to unbolt it from the intake manifold and turn over the engine. It sprays fuel and its fine. While you're there you can also check that all the rest of the injectors are giving fuel. To do that you pull them all and put them in jars (or bottles). Then you pop the airbox apart (4 snaps on the sides) and them simply move the plate inside up and down a few times. This moves the plunger thats inside the distrubutor mounted on top of that airbox which in turn gives fuel.

The auxilary air valve I mentioned gives the engine more air in order to raise the idle when the engine is cold. First locate it. It should be nearby the throttle body. Looks like this.
Then to check it you'll need to first pick up a manual to find the correct internal resistance. Then check the resistance.

So you have fuel right? if not then that plunger is stuck (unlikely but possible). If so then we have to see that you are getting the correct amount of fuel. Unfortunately for that you will need the manual. that involves testing the resistance of of the warm up regulator. This regulator is bolted to to the fuel distributor. Looks like this... You need to look at the manual and see what the resistance should be between the leads on that plug. Then simply check with an ammeter.

 

damn thats a good write up ... well done

 

Thanks I try. Rebuilt myself a vw Rabbit with the same system so this is all very familiar to me.

 

Thanks for the reply. It's definitely got spark, it just takes 10 cranks to start. It tries harder every time you crank it, but still takes too long. Gonna cook the starter one of these days, and I know they aren't cheap. Checked for leaks and the basic stuff, patched a hole in the intake hose. Still has the same problem. Car drives fine, so I don't understand. Must be the cold start injector. Anyone know where that's at on this? It is the 2.0L 4 cyl. Thanks again.

 

I'm having this same problem too. Car is very hard to start when it's cold. If it does start, it'll stumble along on 1 or 2 cylinders for a bit until it heats up. I've already checked the cold start injector and found it isn't spraying fuel, so I'm going to perform the rest of the checks you've described.

 

both of you guys need to check for leaky injectors .... leaky injectors will cause a hard start

 

Definetely sounds like a combination of vacuum leaks and the cold start injector there nn2004. In your case I'm about 80% sure your cold start injector isn't spraying when you start the engine. There are two reasons why it wouldn't spray. The first is that it isn't functioning properly. The other is that the thermo-time valve isn't sending voltage due to it not working. I do not no how to check if the injector isn't working but the thermo-time valve is simply a matter checking the internal resistance with a ammeter and comparing those to the ones in your manual.

As for your problem Phaedrus44, fix your cold start valve but that isn't going to completely fix your problem. It sounds like either your auxilary air valve is not working properly or your warm up regulator (fuel pressure regulator) isn't working properly. The warm up regulator should have a small screen insude it. Cleaning that screen out may just solve that. Give you a little more power too as you'll have the proper fuel flow then.

 

Ok, I found the cold start injector. I didn't take it off for fear of destroying the gasket. Any clue where the thermo-time valve is? I don't have a manual since I don't know how long I want to keep this car yet.

 

I don't know exactly but it is controlled by the temperature of coolant so it should be mounted in the head right where the upper radiator hose connects.

Here is how to differentiate if it is bad.

With the engine cold you can pull the cold start valve out and crank the engine.(only 1 time) See if the cold start injector fires. Extreme fire hazard!!! If the cold start valve sprays, the thermo switch works. If you are experiencing hard starting and long cranking times when the engine is cold, its usually leaking injectors, not the cold start valve/thermo time switch.


It is extremely rare for the cold start injector to fail. If it does it'll leak so you'll know when it doesn't stop spraying.