idle issue after a 30-60min drive

ok i have a 92 sc with around 101,000miles and put on a newer dis mod and change coil and just done headgaskets plugs and wires like not ever a year ago dis was like 2 months ago and after an 30min drive i come home and park my car and start it back up later like 20 min later and it has a really bad idle like its on running on 3 cycliders and not 6 the rpms are goin from 700 on down 2 atleast 250 back and forth drive down the street and get on the car a lil and stop and the bad idle is gone what could make this happen please any help

try recoating the bottom of your DIS with the heat sink grease.....and you may wanna reseal your IC tubes they will expand a bit when heated up and it may have a vacuum leak in there that will cause the RPMs to rev up and down and make it run like doo doo....

Rick

92sclikenew said:

ok i have a 92 sc with around 101,000miles and put on a newer dis mod and change coil and just done headgaskets plugs and wires like not ever a year ago dis was like 2 months ago and after an 30min drive i come home and park my car and start it back up later like 20 min later and it has a really bad idle like its on running on 3 cycliders and not 6 the rpms are goin from 700 on down 2 atleast 250 back and forth drive down the street and get on the car a lil and stop and the bad idle is gone what could make this happen please any help

Click to expand...

two words. cam sensor

I am thinking DIS ignition module also.

well dis was just replaced so i hopin its not that and the cam senor can make the car run like that for 1 min and then drive dont the road 10ft and kind of get on it and ther will be no bad idle any more to me its like after i turn my car off fuel leaks in the engine and when go 2 start it again ther is 2 much fuel and it runs like crap but idk

To test if you have a fuel pressure leak down caused perhaps by a sticking fuel injector, or a bad fuel pressure regulator, get yourself a fuel pressure gauge and hook it up to the tire valve thing called a schrader valve on the fuel rail and do a pressure check.

I think the fuel pressure should stay up for a fair length of time after shutoff, but if it drops right away, then you know its a fuel problem.

Do your diagnosis before you start throwing money at it. It could be a cam sensor acting up, the DIS module could be overheating or even a mouse in the air filter box .

Good luck

yea thanks thats what it seems like. I been workin on car sence i was 8 and im bout 2 be 21 so yea i am really good with cars . now if ther was a leaky fuel injecter wouldnt the car have a bad idle all the time after it has ran all the fuel out the cylinder cuz i have another broken motor mount and it has a lil shake but i dont thinks its a miss