Engine Misfire
#1
Engine Misfire
I have a 2000 Silverado V6 4.3L 2wd under idle you cant tell anything is wrong but once you give it gas it studders and bucks. i have changed the distributer cap the rotor wires plugs and fuel filter but nothing has made any noticible difference. i checked the timing and the timing is good i yoused a firing light and all the cylinders are firing normal no skips or long pauses between spark. i have no idea what to do next and i do not have the money to bring it to the shop if anyone has any ideas please help thanks
#2
Welcome to the forum. Is the MIL indicator on? If so, you need to get it scanned for trouble codes, with freeze frame data if possible. I'd say there's no other way around it.
In the absence of MIL, try running with the MAF sensor unplugged and then with the upstream O2 sensors unbolted (may be difficult, use PB Blaster to loosen the threads and a lot of patience). The former will isolate a misreading MAF sensor and the latter, restrictive exhaust.
P.S. Be very careful not to get any PB Blaster or solvent on the outside surface of the O2 sensors. They measure difference in the O2 content at the tip that hangs in the exhaust stream and outside air.
In the absence of MIL, try running with the MAF sensor unplugged and then with the upstream O2 sensors unbolted (may be difficult, use PB Blaster to loosen the threads and a lot of patience). The former will isolate a misreading MAF sensor and the latter, restrictive exhaust.
P.S. Be very careful not to get any PB Blaster or solvent on the outside surface of the O2 sensors. They measure difference in the O2 content at the tip that hangs in the exhaust stream and outside air.
Last edited by EinST; March 25th, 2011 at 5:46 PM. Reason: Added welcome and warning
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