# 1992 jetta, very rough idle and stalls



## dreadlocker (Oct 8, 2009)

I just bought a 1992 VW jetta GL 1.8 liter about a month ago, and it ran perfectly fine up until this last week. I started the car and the idle was very rough and was the car was shuddering a bit. When I drive it at the top of each gear or while maintaining a speed it bucks and shudders a bit, but the car is just fine while accelerating. 
When I go to slow do to stop and push the clutch in the car just stalls out and dies. It has been starting right back up after stalling, but the idle problems and the shuddering remain, unless I am speeding up. The first time this happened I put some fuel injector cleaner in it and the problem seemed to clear up. Then 2 days later the same thing started happening again. This time I changed the fuel filter, and started the car and it seemed to clear up right away, but again after letting the car sit for about 5 hours the same problem came back.
I don't want to just start throwing money at it just to find out it was something stupid. 
Any Suggestions?


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## GeekWagens (Oct 7, 2009)

*Re: 1992 jetta, very rough idle and stalls (dreadlocker)*

try removing the ISV and cleaning it out with some carb cleaner! That may help


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## dreadlocker (Oct 8, 2009)

*Re: 1992 jetta, very rough idle and stalls (GeekWagens)*

Took the car in the changed and replaced the spark plugs and cleaned out the ISV. 
2 days later the same problem starts again, car stalls when i push the clutch in and it won't idle at all now.


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## BiH (Nov 27, 2000)

*Re: 1992 jetta, very rough idle and stalls (dreadlocker)*

take the TB off, clean it and see if idle switch is all ok. start the car, open the hood and turn the tb so it revs up. when you let it go listen to the "click" under the TB. if it doesnt click then your idle switch is missaligned! mine was and when I fixed that it ran fine for a while. its giving me problems now but I tink i just need to clean everything and it will be all dandy


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## dreadlocker (Oct 8, 2009)

*Re: 1992 jetta, very rough idle and stalls (BiH)*

What is the best way to check that switch, do you need to take it off, or can adjustments be made to it while it's still on?


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## BiH (Nov 27, 2000)

*Re: 1992 jetta, very rough idle and stalls (dreadlocker)*

you can check if its aligned while everything is still on the car, just listen for the click when releasing the TB. if needed to adjust TB should be removed.


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## dreadlocker (Oct 8, 2009)

*Re: 1992 jetta, very rough idle and stalls (BiH)*

I double checked what the shop had done to my car, changed spark plugs, and on the bill they said they cleaned the ISV. I looked under the hood and they didn't re-attach the wires to the ISV. The car had ran fine for 2 days before the problem with the stalling and studdering showed back up.
I plugged in the ISV wires back in, and the car would start and idle again, but was still running very rough. I drove it around the block and it would stall at stop signs when I would push the clutch in.
Could they have set the Idle to low when they were trying to get it to idle without the ISV plugged in?


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## Thehatta (Feb 9, 2009)

*Re: 1992 jetta, very rough idle and stalls (dreadlocker)*

...is the car distributed...and if it is have you check your timimg??? also try toying a little with the idle screw, get it so the cars idleing between like 800-100rpm(spec per mitchell5) see if she runs better, i know right now i have a cabby with a 1.8 cis system...and my distributor is absolutly frozen to the block...she gets her daily wiggle with some PB blaster...soon she will be timed


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## dreadlocker (Oct 8, 2009)

*Re: 1992 jetta, very rough idle and stalls (Thehatta)*

I turned the idle screw without the isv connected while my wife tried to start the car. It wouldn't idle with the ISV disconnected, but i put the idle screw to where it was almost starting without the ISV. 
I then plugged in the ISV, and it idle's fine the studder is gone, and it's been fine for 3 days now.
Now the only problem is that after the car warms up a bit, the oil light and buzzer come on. Had the oil changed when I bought it and put in heavier weight oil. The buzzer shuts off at 3k RPM while driving. I know there are 2 sensors for this, but not sure which one is bad and where it is located.


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## thesumof41is5 (Aug 6, 2009)

*Re: 1992 jetta, very rough idle and stalls (dreadlocker)*

there are 2- one is on top of the oil filter flange and is yellow, and the other is on the right side of the block (looking under the hood) right under the valve cover and is brown. I would replace both, they are ~3 bucks from GAP, and check the wiring, and how long has it been since an oil change and what oil do you have in it?


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## Thehatta (Feb 9, 2009)

*Re: 1992 jetta, very rough idle and stalls (thesumof41is5)*

yea replace both the sensors one is for idle and senses when oil pressure drops below .3 bar and only when the cars at idle, the other senses when the oil press drops below like 25psi????(not positive) when the engines over like 1k rpm....so both sensors would have to be faulty if the lights staying on till 3k....anyways those things usually start leaking when they get old its just a good idea to replace em


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## thesumof41is5 (Aug 6, 2009)

*Re: 1992 jetta, very rough idle and stalls (Thehatta)*

exactly.. if the problems come back try this,
http://forums.vwvortex.com/zerothread?id=4624021
It's definitely cheaper than a new ISV, IMO ISV's aren't necessary either


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## dreadlocker (Oct 8, 2009)

*Re: 1992 jetta, very rough idle and stalls (thesumof41is5)*

I'd looked at the delete ISV threads before, but since I can't get it to idle without the ISV right now that's not an option. 
Thanks for the info on the oil sensors though, anyone got part numbers?


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## thesumof41is5 (Aug 6, 2009)

*Re: 1992 jetta, very rough idle and stalls (dreadlocker)*

http://www.germanautoparts.com...150/2


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