I own a 1989 2226cc audi100 quattro and would like to solve the starting problem. When cold the engine seems to be turning over for far too long before actually starting although it will start first time if cranked over for long enough. This cant be good for the starter. I have checked the cold start valve (engine cold)which seems to be working, it delivers a strong cone shaped amount of fuel everytime. I was going to check the warm up valve but according to the manual this device is to richen the fuel mixture when the engine is running and warming up so I dont think that its anything to do with that. Its baffled me!!!
Any ideas?
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This sounds like the problem I experienced on a 1985 1994cc Audi Coupe. Is the problem worse in damp/rainy conditions? If this is so, new injector seals solved it.
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The warm-up regulator is EXTREMELY important for cold starting, as it is this that controls mixture according to engine temperature. It's function can only be checked by carrying out a system & control pressure test with appropriate pressure gauge, but if car is driveable as soon as you do get it started it is probably OK - if it is stuck at "hot engine" pressure the car would be VERY difficult to drive until fully warmed up.
The cold start injector is an additional source of fuel for very cold starts, and should only spray for between 2 and 8 seconds from beginning of cranking. It is controlled by the thermo-time switch, which controls the duartion of spray time according to temperature. If the thermo-time switch is faulty and the cold start injector is spraying all the time you are cranking it will flood the engine and make starting very difficult. In our dubious climate the cold start injector is not vitally important, and in fact will only operate very briefly/infrequently. If over fuelling is the problem the engine may start better with it (electrically) disconnected.
HTH, Adam
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It runs fine once started so I will try what you suggested and let you know the results.
Thanks very much
Pete.
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Success!!!
Disconnecting the valve has meant much easier starting so it does sound like the thermotime switch was causing over fueling. Question is should I leave it at that or replace the switch? I would like to locate the switch and understand how to replace it if you dont mind replying to this e mail?
I worked at a vw/audi garage for 9 years when I left school but have been out of trade for some time now and hence not kept up to date like you obviously are. Thanks very much.
Pete.
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Glad to hear that Ses !
95% of the time, in this country, starting without the cold start injector will be OK. But, as we go into winter, it really is best to get things right. I can't say accurately where the theromtime switch is on your car, but it is usually around the thermostat housing area to the front of the cylinder head. It may be located close to the coolant temp sensor, and if so the thermotime switch will be the bigger of the two, usually around a 19 - 23 mm spanner size. It should have a temperature identity stamped on one side, along with a Bosch part number. It will have a two-wire plastic wiring connection plug. It simply unscrews, and new one should be fitted with a new copper washer (only do this with cooling system cold, and quickly, and you will not loose too much coolant).
Good Luck ! Adam
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Warm up regulator, I got one for my brother's 1988 Audi 90 2.2 Quattro from Smashing VWs £40 easy to replace. They will post.
Smashing V.W'S
Unit 4 119, Jack Lane
Leeds West Yorkshire
LS10 1BS
Tel: 0113 243 5635
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if you have checked the basics ie ignition systems and fuel pump, check static engine timing and check if your engine has a firing point sensor (crankshaft sensor)
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