I have a olds ciera with the 2.8 so i figured i can ask for help here as well.

I have checked the coils and control module and they are good. The o2 sensor has been changed to to a 44 cel code. I have also changed the plugs and wires and pcv valve as well. I am at a loss to what to check next.

Has anyone had simliar problems with their 2.8's? any and all help is greatly appreciated.

Are there any common problems with these motors and the ignition system.

in my old cavalier with a 3.1 i had a misfire problem that was caused by the rectifier bridge that the ignition coils were mounted to. it would get an intermiten connection and it would work when it wanted to. i picked up one with 3 coils from the junkyard for about $40.



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scrawnyguy18 wrote:in my old cavalier with a 3.1 i had a misfire problem that was caused by the rectifier bridge that the ignition coils were mounted to. it would get an intermiten connection and it would work when it wanted to. i picked up one with 3 coils from the junkyard for about $40.

I took the control module that the coils mount to and it tested out fine. so i dont know what to do now

Check ur distributor cap,assuming it has one for cracks,or burn marks inside at the metal contact points.IF its damaged this would be a result.Also and loose or worn vacumm lines and do a fuel pressure check for proper psi coming from the fuel pump.Since I do not know the yr model if equipped with a egr check it for proper operation.The rubber diapram inside should be solid no leaks and if a pintal is visable make sure it moves up and down freely.Unless have a weak injector which u would need to check each one separate that could b a issue too.A clogged fuel filter may b a problem as well.That's a few things to check out.Not really fluent with the 2.8 but regardless symptoms of miss fires are fairly common with what the problem could b.

Ron Love wrote:Check ur distributor cap,assuming it has one for cracks,or burn marks inside at the metal contact points.IF its damaged this would be a result.Also and loose or worn vacumm lines and do a fuel pressure check for proper psi coming from the fuel pump.Since I do not know the yr model if equipped with a egr check it for proper operation.The rubber diapram inside should be solid no leaks and if a pintal is visable make sure it moves up and down freely.Unless have a weak injector which u would need to check each one separate that could b a issue too.A clogged fuel filter may b a problem as well.That's a few things to check out.Not really fluent with the 2.8 but regardless symptoms of miss fires are fairly common with what the problem could b.

Thanks for the help. I do not have a distributor cap. I have DIS and the coil packs and the module are ok.

Has anyone had problems with the iac vavle on the throttle body?

The iac would throw a code 35 ,which u would need to check the minimum idle speed,and a fuel pressure check,a leaking injector and anything blocking the tbi.If a code 35 was set u would need to replace the IAC valve.Thats straight out of the manual or manuals I have which are three that I own.

Ron Love wrote:The iac would throw a code 35 ,which u would need to check the minimum idle speed,and a fuel pressure check,a leaking injector and anything blocking the tbi.If a code 35 was set u would need to replace the IAC valve.Thats straight out of the manual or manuals I have which are three that I own.

Problem has been solved. The last owner messed up. when they were messing with the fuel regulator they disconnected injector for cyl #3. plugged it back in and all is fine. thanks go all who helped

Sweet glad to here that it's corrected.

ok maybe i spoke to soon.

I still have a slight misfire at idle which doesnt bother me a great deal but would like to get rid of it. here is what its doing now.

i have a 1.8 mile drive to work and it runs fine here. When I take into town and run it for a longer period of time it seems to almust chug when at a stop light. I do not notice it at all when driving. It is very evident when stopped and in gear. It seems like a multiple cylinder misfire, but I am not throwing any codes at all.

I have changed the plugs, wires and o2 sensor when it threw code, the previous owner had the fuel pressure regulator worked on.

I even notice that sometimes during downshifts at night i can see my headlights dim for a second.

A friend suggested the egr valve since it worsens as the car runs in big city traffic and heats up compared to highway travel

all help is still greatly appreciated.

Yes the egr can cause irratic idle and stalling if it's not working properly.Just remove it and clean all the carbon build up with some carb cleaner and make sure the metal pintal inside of it moves freely.I use a wire brush to clean as well.IF the pintal sticks or if ur egr has a visible rubber diaphram make sure it's not cracked,if it's a sealed unit and after cleaning it the problem is still evedent replace the part.Most egrs have a vac line going to them unless they are electrically connected ,u can just disconn the vac line and if the problem goes away that pinpoints the issue.Just try the above cleaning and go from there based on what u find.Worst case replace the egr with a new one.The symptoms are as stated idle weird once warmed up and almost stalling out as well.I hope this helps.

the egr is only 17 dollars so i think im going to change it this weekend.

it idles good when cold, but when the car is drving for a longer duration and warms up it chuggs, i dont think it i will stall but it seems like an injector unplugged would act.

That's a pretty inexpensive fix in my book.I think based on ur symptoms the egr is the problem,since once it reaches oper temps it start to malfunction.Good luck.

Do EGR valves function during open loop? If they do, then that's not the problem.


What brand of O2 sensor did you use? Bosch sensors are known to fail or give false voltage readings out of the box.





1997 Pontiac Sunfire
1993 Lexus ES300
1982 Kawasaki KZ550 LTD