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Hello.
My grandma is driving a 1986 Audi 100 1.8 petrol engine,and recently it showed a new problem. The car dies when at idle. It runs fine when you apply the gas pedal and when the choke is pulled out,but it dies right after you step off the gas pedal or push the choke back in and are stationary. The problem started when the screws from the air filter housing on top of the carborator got loose and fell into the carborator, I “fished” them out and it seamed to have no problem afterwards,but soon after that the idle problem showed up again,and this time all the screws were in place.(where not in the carborator). So I changed the spark plugs,spark plug leads but still problem exists. Checked the distributor cap,all seems fine.
What could be the problem?
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If those screws were in the K-jetronic fuel injection system, they were not just random fasteners, they adjust the idle position of the sensor plate and the idle mixture. You need to have them put back in and adjusted right.
[quote=”Zinammo” post=78501]Hello.
My grandma is driving a 1986 Audi 100 1.8 petrol engine,and recently it showed a new problem. The car dies when at idle. It runs fine when you apply the gas pedal and when the choke is pulled out,but it dies right after you step off the gas pedal or push the choke back in and are stationary. The problem started when the screws from the air filter housing on top of the carborator got loose and fell into the carborator, I “fished” them out and it seamed to have no problem afterwards,but soon after that the idle problem showed up again,and this time all the screws were in place.(where not in the carborator). So I changed the spark plugs,spark plug leads but still problem exists. Checked the distributor cap,all seems fine.
What could be the problem?[/quote]
Is this a carburetor or fuel injected?
Hello, just a quick thought and a random shot in the dark.
Have you actually tried to clean the carburetor with some carb cleaner?
I say this ’cause baybe one of the screws moved some dirt into one of the passages and now the idle circuit is clogged.Also, you might try to do the hack method of choking the carb with a (CLEAN! 😉 ) rag after having revved up the engine; the sudden depression the rag will create will suck in any dirt and possibly unclog the obstruction.
Also, a method I casually discovered with the carb of my bx, could be to screw and unscrew again (putting the screw back into the position it was in the beginning) the idle mixture screw.
In the case of my bx this had some unclogging effect because now the idle is waaay higher and more stable.
Please take a mental note of the screw’s position before starting, and return to that position afterwards.I counted the half turns of the screw and the direction, then reversed the same half turns.
Then try the idle again.
Also, I’m curious, does the idle change with the engine warmed up?
And one last question; can you actually hold the engine at idle rpms with the throttle pedal slightly pushed?
It might just be the cable linkage got moved and the idle air position got too closed and now it’s choked, so, if you can keep the engine running at idle rpms, you can try adjusting the idle air position of the main butterfly; it’s usually adjusted with the screw that sets the idle rpms.
This screw in fact sets the resting position of the main butterfly valve in the carburetor.Please keep us posted! 🙂
Live long and prosper (and stay dirty!)
10nico
Well it took a while,but the problem is fixed.
It turned out to be a broken vacuum line. Replaced the line,fixed the problem.
Thank you very much for your support.
Vacuum leaks. They cause so much trouble and are often overlooked. Good find on your part! Thanks for keeping us up to date and for using the ETCG forum.
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