Check Engine Light

[trover]

Does anyone know the difference when your check engine light is on and stays on versus the check engine light flashing?

[ZL1power69]

this happened on my 95 jimmy cpi. when the light is flashing it means the engine is misfiring. i had this happen because my O2 sensors were shot and told the computer to flood the engine. i replaced both and that fixed all problems. if it is on solid then its just a normal trouble code. hope this helps.

[trover]

Originally Posted by ZL1power69

this happened on my 95 jimmy cpi. when the light is flashing it means the engine is misfiring. i had this happen because my O2 sensors were shot and told the computer to flood the engine. i replaced both and that fixed all problems. if it is on solid then its just a normal trouble code. hope this helps.

Thanks, it helps. I have been having problems with it lately and this morning it wouldn't idle very well at all then the "Check Engine" light started flashing. Here is my problem, maybe someone can provide some insight into it.

I have a 2001 Jimmy and from stop when I would accelerate my car would shake and feel sluggish, like it was missing. As my car's RPMs increased the shaking would slowly go away. When it hit around 2500 RPM I wouldn't feel it anymore until it shifted to second then I would feel it all over again. When I am staying at a constant speed the car runs smooth. It use to idle good too until this morning, it idled like crap then my check engine light started flashing. But again this morning as I was in park, I got my engine RPM's up and it smoothed itself out. I have changed my spark plug wires and distributor cap. I replaced my spark plugs 15,000 miles ago but will probably replace them again today. Oh, my car has 95000 miles on it too.

[ZL1power69]

mine ran horible before i changed the O2's. it would barely start and when it did it through a po300 code, which is a multiple misfire. basically the whole engine was missing. after it got above 2500rpm it would smooth out and be fine at highway speeds. when i slowed down it would flood and the light would blink. My advice would be to replace the O2's. they are about 40 bucks a pop. in my case that fixed it so it was driveable. always try the simple things first. my cpi is leaking so that is part of the problem but i am replacing that in the next week. also if you haven't tryed this yet, replace the plug wires or check them for damage. my coil wire grounded out on the trany dipstick and cause a slight mis. again try the simple things. hope my rambling on is helpful, lol.

by the way my truck is a 1995 with 199,600 miles.

[trover]

Originally Posted by ZL1power69

mine ran horible before i changed the O2's. it would barely start and when it did it through a po300 code, which is a multiple misfire. basically the whole engine was missing. after it got above 2500rpm it would smooth out and be fine at highway speeds. when i slowed down it would flood and the light would blink. My advice would be to replace the O2's. they are about 40 bucks a pop. in my case that fixed it so it was driveable. always try the simple things first. my cpi is leaking so that is part of the problem but i am replacing that in the next week. also if you haven't tryed this yet, replace the plug wires or check them for damage. my coil wire grounded out on the trany dipstick and cause a slight mis. again try the simple things. hope my rambling on is helpful, lol.

by the way my truck is a 1995 with 199,600 miles.

I changed my spark plugs and now it idles good. My check engine light went off too. However, it is still sluggish when I accelerate when the RPM's are low. Could it be a fuel pump? Anyone have any suggestions? So far I have new plugs, wires, and distributor cap.

[ZL1power69]

not out of the question. check the pump and fuel filter.

[vavance]

o2 o2 o2 o2 o2 o2 can't say it enough. when i changed those all was well. got a 99 envoy with 100,900mi.

[BlazerLT]

Also, plug change is not a tuneup.

Cap & Rotor
Fuel filter
Wires
PCV valve
Air Filter