i have a 3800 series 2 in my monte carlo and it idles smooth and runs perfect untill you accelerate hard and it seems to power surge but if im going 65mph on the interstate and there is a hill or i need to gradually pass someone it actually develops a pretty nasty miss but no engine codes!! i am soooo stumped ive tried several different throttle bodies with good maf and tps sensors it has a new upstream o2 sensor and nothing...ive checked for vacuum leeks and nothing...just did a tune up on it...new plugs wires and i even switched out the ignition module and coil packs with ones that i knew where good and i CANNOT figure it out and its getting old...oh and it will occasionally backfire when i need to pull a hill or pass someone but its not every time.....pleasee help!!
How do the spark plugs look? A misfire is generally bad coils, bad plug wires, or bad plugs. When you pull the plugs look for anything different. They should all be a light gray color. If any are black then you will know where the problem is. Also, have you checked your fuel pressure. Should be about 48 psi.
moved to it'* proper Mechanical Section. General Chat is for items that affect all platforms and "General Chat". It really helps the GearHeads, others with ownership of same/similar Models, the Forum regarding search bots, and our own internal search engine when we keep things in order. Thanx.