90 Lumina

Hi all -

I'm posting this for a friend. His 3.1 90' Lumi runs terribly when the engine warms up. He brought it to a shop, they (said that they) checked all major things + checked for codes, etc. The owner of the shop told him that it ran this way because "it is old." This annoyed me to hear, except that he didn't charge him. Phew. Anyway, any ideas? New plugs, wires, and ICM have been installed within the last couple months (I do realize that this doesn't mean that one of them could not still be the problem, but seeminly unlikely).

Thanks!

Matbe After Other Worked Was Done You Need To Do An Idle Relearn

could you elaborate when you say it runs terribly? Does it jerk, cut out, die, what?? Surely the answer to this question would prompt an answer from someone here.

Like Gw84 said, can you be a little more specific on what "runs terribly" means? In the meantime, if the new plugs/wires are Bosch, get rid of them. Stick with AC-Delco or Autolite. Usually, if the car runs worse when warmed up, and no codes are there, it indicates a bad EGR valve. The problem is that this car uses a digital EGR, which is very costly ($200+). I'd hate for you to crap shoot a $200 part and find out it isn't the issue.

wasn't the coolant temp sensor an issue in these where it would run good untill the 02 sensor heated up, then the teps sensor was lying to the computer telling it to dump more fuel than it should? I dont know, or am i just shooting stupid ideas around? I suppose one could test something like this, just dont quite know the resistance values for specific coolant temperatires.

Sorry, I should have immediately elaborated, I was in a hurry. It simply feels like it's missing when you're on the throttle from the little time I spent with it it seems to be fine until you're at hwy rpm's. - and then it jerks while you're going down the road. (It also does it at these rpm's in park, also, so it's not trans. related). I like the EGR suggestion. I happen to have an extra one lying around I could give him. I'm not sure what kind of plugs/wires he used but I'll be sure to ask. You're right, Bosch is horrible. Could it also be that the EGR passages are clogged? Can that make it run rough?