i have a 98 c1500 with the vortec 4.3 v6. my check engine light just came on today while i was cruising down the highway. i took it to autozone and used their scanner... it told me it was a random multiple cylender misfire. the truck dosnt have a rough idle and the mid rpms are good the engine dosnt shake or anything so i thought maybe it was just the plugs loaded up... i know it really couldnt be that but it gave me an excuse to beat it. so i got on it in first and took it almost all the way up, when it hit 4 grand it made a loud backfire and blew a ton of black smoke but ran perfectly fine afterwards and the check engine light is still on.. i have not a clue whats goin on i replaced damn near the whole ignition system about 3 months ago... ac delco professional platnum plugs, autolite wires, new cap, new rotor, ignition coil, ignition moduole, crank position sensor, and i put a k&n air filter on it. any help on this situation would be greatly appreciated thank you. keith
- posted
18 years ago