I drive a 2001 sun fire, with the 2200 engine. when i start my car it runs fine, after it warms up just a little bit it begins to miss at a idle. wile it is missing if i give the car a shot of gas it revs up to appx. 3000rmp and stays there for some time before slowly coming back down to normal idle range and then it begins missing again. if i run the car like this until it is fully warmed up sometimes it goes away. I had the car connected to a computer and it threw the code ( i think it was P0171, not 100% sure) for running lean, but at the same time the computer did not detect a engine miss.
i have already replaced the fuel filter, fuel pump, spark plugs, plug wires, and ignition coils. also i have checked each of my injectors. everything seams fine to me. Does anybody have any ideas at all?
Are you getting check engine light on now?. If so I would recommend getting the trouble code scanned, That should narrow it down for you.
Good Luck.
How did the plugs look when you pulled them? Reason I ask is my car did pretty much the same thing with the hanging idle and bank 1 lean code. It would miss when accelerating and idle was crappy. Checked for vacuum leaks first because of the lean code, found none. Pulled the spark plugs and they were BLACK so I was running pig rich even though I was popping up a lean code. Problem for me ended up being the first O2 sensor.
Thanks for the info. im def gonna check the o2 sensor as there cant be to many more things it could be.
where exactly are the vacuum lines located? and how many ?
Unplug the 02 sensor and see if the problem goes away, i'm betting that is your issue. Just fixed mine this weekend, it was doing the same thing. Unplugged the o2 and it was fine, so i went and got a new 02 and problem is fixed.
well ill have to try this later this weekend, in the mean time is there any harm in running the car like this?
If ya got black smoke coming out the exhaust them you are dumping raw fuel thru the engine wich could result in damage.
yea check the o2 sensor
98 Sunfire SE Coupe(beater car)
02 Monte Carlo SS - L67 Top Swap, 3.6 Pulley, VS CAM, GMPP Catback Exhaust, DHP Wideband Tuned 13.7@101.59mph
Pull the plugs and look at them. If they all look the same, continue with the O2 sensor as advised.
If one is completely different looking, different color, odd deposits or even clean as a whistle you've got single cylinder issues. Maybe a bad injector, bad valve seal, bad ring, cracked head, bad head gasket, etc.
Take a compression test also, that tells you volumes about the engine's health.
Dave
