Idles fine but stalls at stop signs
10-18-2005, 08:45 PM
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Idles fine but stalls at stop signs
Hi, I have a 1990 100 2.3 5-cyl with a strange problem. The car starts alright and will idle around 1000 no problem, but after warming up and driving for about 15 min, everytime I stop at a stop sign, or slow to corner the engine speed drops down to 300-400 rpm. Of course this often ends up in a stall. It's got me really scratching my head (and braking with my left foot so I can keep the car running). Anyone seen anything like this?
10-19-2005, 04:02 AM
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Where is your temp gauge?
You said "left foot braking" so I assume it's an auto. There is always a slight load on the engine with an auto and a cold engine will not hold an idle very well. Another cause could be the idle switch which lets the ECU know that the pedal is at idle and needs to have the idle solenoid valve give a proper idle of 850rpm. Or it could be the idle sol valve itself. They can be cleaned with carb cleaner.
Check those items along with the suggestions of the others.
Check those items along with the suggestions of the others.
10-19-2005, 10:35 AM
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Re: The MFTS does not control the ISV on my car
I don't own a 100 but on the 5K there are two one pin coolant sensors near the MFTS. One is for ECU one is for ISV.
The MFTS drives the temp gauge and gives an overheat signal to the AC head. Check that signal if your compressor won't come on. I think it has one more function that I can't remember.
I'll go with vacuum leak also or throttle position sensor.
The MFTS drives the temp gauge and gives an overheat signal to the AC head. Check that signal if your compressor won't come on. I think it has one more function that I can't remember.
I'll go with vacuum leak also or throttle position sensor.
10-19-2005, 10:43 AM
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You may be right, I may have forgotten...
I replaced the MFTS and one of the other temp sensors at the same time, fixed an idle problem and the temp gauge in the dash. Not sure which was which.
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10-19-2005, 11:37 AM
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Re: Where is your temp gauge?
Wow... alot of things to check. I'm tending to lean towards thinking it's sensor-related since the appearance of the problems is linked directly to temp. When the engine is cold it idles at almost 1000 (by the dash gauge of course) but once it's been driven for a while it won't hold it.
I'll have a look at it tonight again. Thanks to all for the suggestions.
I'll have a look at it tonight again. Thanks to all for the suggestions.
10-19-2005, 02:54 PM
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I had the same problem with my previous '91 100q NA
It turned out to be the idle switch on the throttle body not making contact like comp_jas suggested.
Just adjusted the stop a very little bit and ran fine from then on.
Just adjusted the stop a very little bit and ran fine from then on.
