Idles like ***** after the car is hot????

joew623

Registered User
In my SC, when the car is cold...it starts right up and idles perfect, i drive somewhere...shut it off...go into a store for like 15-20 minutes...come back out and start it...it idles sooo bad like its about to stall and i have to give it gas to about 3 grand and hold for a lil to keep it running, and as soon as i drive it maybe 20 feet...its fine and will idle sooo smooth from there on out....i shut it off....wait 30 seconds and start it....beautiful idle....shut it off again...wait 3 minutes....start it....beautiful idle...shut it off....wait 10 minutes...start it up...and wont idle worth a crap and stalls...??? any ideas??? my friends SC does the same thing and he replaced his crank position and it still does it...
 
Have the same problem man... Only when it gets up to operating temp (middle of the "O"), then I shut it off for 10-15 min, start it up, shakes, and idels bad for a few minutes. It's a mystery! I'm curious about an answer to this as well. Any ideas guys?
 
This topic comes up every year right around this time. One of the theories is that winter blend gas is the culprit. I t has a lower boiling point and when the engine compartment gets hot, and sits for about 10-15 minutes, it percolates in the fuel rail causing hard starts and rough running untill it clears out. Mine does this it seems every year and then just up and quits doing it once warmer weather is here to stay and the winter additive is no longer used.

The other theory is that some injectors are leaking down the residual pressure in the fuel rail and floods the cyinders until it clears itself, or a leaking fuel pressure regulator.
 
are there any fuel additives that would help?? cause this really sucks starting it and having everybody look when its all shaking and stalls....
 
I have basically the same problem, it idle's real ruff and then if I let it sit too long it just die's. It's strange that this happens to all of us.
 
Warm start idle problem theory...

Well, I would not consider additive, but the fuel aspect is an interesting thought. It does seem to happen when it is warmer out AND on BOTH my 93 and 94 there was increased "bubble noise" in the gas tank when I turn the key to the on position before starting.

Another theory that was posed was a scary one, but made me think.

At shut down the cooling system decompresses and if there is a small crack in the head gasket, the system will leak into a cylinder (or cylinders) and at system start would have to burn off.

This does not explain the increased bubbles in the gas tank, however. Living in Chicago all I have to do is wait a couple days to have a 60+ degree day and another couple days to be below 40 again (ha ha), but this week is a good test of that.

As far as I could remember, the problem did not start until the engine(s) got up there in mileage so that led me to believe the head gasket theory. Now, my 94 is doing it and I suppose I can run her around a bit when its warmer, wait a bit and remote-start the car and stand behind it to see if I detect any coolant smell.

The original engine on my 94 smelled of coolant at warm starts and sputtered like that, but I have not tried this one and recently it has exibited the same symptoms.

I'll see what I can figure out.
 
Boy you guys just HAD to start this dicsussion didn't you..LOL.

Sure as hell, yesterday the temps here in Toronto went well into the high 50's and lo and behold...cough cough, sputter sputter after sitting for 10-15 minutes when the engine was hot.

Ah yes spring has sprung and here we go again...LOL. This car has done this ever since my son and i bought it over 3 years ago and it goes away later in the spring and early summer. Hence why we theorized about the winter fuel additive. I won't be doing a thing about it because I know it will go away.

The only sure I know of is to either drive it ahead 20-30 feet and it stops or ev it to about 2500 and hold it there until it clears.
 
It sucks so bad though cause everybody looks at my car like its a piece when its all shaking and barely running...
 
Whenever my car does it i just curse at it a few times then put in reverser giving little throttle once in reverse, to keep it from staling, and just leave.
 
Go BUY a NEW DIS module.

I had the same exact problem. I would drive to the bank wait in drive thorugh get the car up to full operating temp and then park for 15-20 minutes. Go out and the car would stumble and miss. This had happend a few times before, but only after a quick heat soak. The day before driving to Indiana, about 300 miles, this happens all four times on restart that day. A friend of mine pulled a spark plug wire from the coil and held it close to the coil while I cranked it. Some times there wasn't any spark. I replaced the DIS and haven't had any more problems. Drove up to Indiana that day and stopped at a McDonalds after one hour of driving. Went out there about 20 minutes after eating and it fired right up and ran smooth. It's been two weeks now and no more problems.

Jerry
 
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Where can I find this module on the 94?

One thing I found odd on my 94 was the absence of the DIS module. Do 94-95s have them?

I would like to end this problem, but if the problem is electrical then why does it only happen when its warm outside?

For instance, it is now 40-some degrees here and it has not done it yet.

Not to mention the bubbles in the gas tank either which I have always believed accompanied the miss...

Curious little friggin problem, eh?
 
Well in my case it wasn't gas. I had this problem last summer too. The type of driving I do isn't usually drive then let car sit 15 minutes and then restart. So it only happened a few times last summer. When I would drive to UPS up the interstate then try a restart about 15 minutes later. Usually I drive somewhere and the car sits a while. The DIS on a 94, 95 has one long connector and is on the pass side front inner fenderwell next to the air cleanler. 89-93 are mounter on the A/C compressor bracket and have two connectors and are subject to engnine heat.
 
The DIS is very very unlikely just by the sheer numbers of people experiencing this problem. Not saying it couldn't be, but driving it 20 feet usually does not clear up a DIS problem nor reving it up for a moment or two.
 
I know what you mean. I didn't think there was anything wrong with my DIS either. If a engine misses after it heat soaks it is either fuel or spark. With fuel injection you have a pressurized fuel rail and a regulator to return unused fuel so vapor lock is a thing of the past. I have a one year old Ford ISC so that is in perfect working order. If I got the engine hot and then let it sit then restart the engine would mis and stumble. Even holding the thottle down to 1500 rpm did not clear it up immediately. After about a minute the engine would run ok. Now the engine starts up and idles perfect since the new DIS. I will keep everyone informed on my situation.

If the problem gets bad enough you may be able to hook up an inductive timing light to a spark plug wire, and see the firing pattern right when you have the problem.

I doubt very much that winter fuels are the problem as other fuel injected cars would have the same problem.

Jerry
 
ME TOO!!!!

I have had this problem in my 89 and now my 90. Did a lot of replacing parts in th 89 to 'TRY' and fix problem. New DIS, Cam Sensor, Crank Sensor, Fuel Filter, ran injector cleaner a few times. Nothing seemed to cure it. I thought, winter fuel. Last summer, in the dead of summer, it would do it randomly. I figured the tank was full of crap so I had it drained cleaned and new stock fuel pump installed. Sure enough...nope, problem still there. Both my cars have high miles on them so I am guessing that it must be a high mileage problem? I am going to have someone start the car for me next time it has been sitting warm for 10-15 minutes and see if it smells like anti-freeze. I hope not, that would mean I might have too cars with leaking gaskets! Then again my 89 has done it since I bought it 2-3 years ago. I would think the gasket would have totaly blown out by now considering the way I drive it!

Joe

P.S. So I am assuming that no one really has a total cure for this?
 
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