Rough/surging idle, dies. 91 Sunbird.

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I have a 91 Sunbird with the 3.1 and a manual tranny.

About 6 months ago I replaced the coil packs to fix a rough idle. Everything went fine until about a month or two after the fix, the car started having a rough idle problem where it would surge to about 2000 rpm after almost dieing. It will continue this surge/almost die/surge until you start driving and then it runs fine on the road. If you push the clutch in when coming to a stop or to downshift, it could die. It will start right away again, but still has this issue at idle. This is only when the car is at operating temp. It idles fine when cold and has plenty of power, etc when driving. If left to idle on its own after start for about 10-15 min, the surging starts happening again and kicks on the check engine light. The code reveals a rich condition but goes away once on the road for a few miles and the light goes out.

The O2 sensor was replaced to see if there would be any change and while it helped a little, did not correct the surging problem. There is also a distinct gasoline smell coming from the engine compartment once the car is shut off and has sat for a minute or two. It's noticably more around the intake plenum and moreso when it has just been filled with gas. I suspected a leak in the gas tank but there is no wetness on the tank nor any smell around it. I have not found any pooling on the engine nor has flourescent dye indicated where any leaks may be. I think the two symptoms are related but have not yet determined how.

Any thoughts/opinions/experience with this one? If there is anything more you need to know, please ask me...I had this all typed in before but timed out when I went to post so I may have forgotten some details this time around.


posted by  dennikro


posted by  dennikro

Well, problem solved. After reading several other sources, it was determined to be the fuel pressure regulator. Replaced that part (along with the fuel rails) and it runs incredible now compared to before. The job was relatively painless and only took about 2 hours to complete with breaks in there too.

posted by  dennikro

my car will die on the road after warm up also smell gas was thinking crank sensor do you think it could be the fuel pressure regulator
any way to check it car is giving me no codes
Thanks Chad

posted by  chadsdc

Hard to say without a little more detail. What kind of car is it? What kind of engine is in it? Any other symptoms? I tried to describe my problem in as much detail as possible. Maybe you can use my original post as a template to provide the info you need to divulge, plus any additional info you deem necessary.

posted by  dennikro

93 olds achevia 2.3 dohc has misfiring problem also but fixed it with coil housing spark plugs and boots seems to olny die at higer rpms after warm up or after starting and trying to take off again wont start for a few minutes after it dies almost like it has to cool down
thanks chad

posted by  chadsdc

Sorry Chad,

I'm not familier with that engine at all so somebody else will have to take the reigns on this one. Hopefully you will get a response on it. I would suggest starting a new topic about it if you haven't already. That way it will be a new entry on a new topic/vehicle.

posted by  dennikro

hey i have a 1988 mazda 626 n i want too put a performance upgrade on it what would be better for driving around the street a superchager or a turbocharger? because people i know want to race me when i do get one but i want to beat them off the line and to the finish. i know that turbochargers give u turbo lag off the line untill u reach high RPM's and then give more power then a superchager but a supercharger gives u power from the start but how long dose it last??? please help! :ohcrap:
thanx jay_51

posted by  jay_51

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