1. Home
  2. Chevrolet Trucks
  3. '89 GMC Sierra 4.3 Engine "Misfiring"

'89 GMC Sierra 4.3 Engine "Misfiring"

I posted a while back same issue. Sometimes it runs great and sometimes the engine "misses." Last time I noted that I had relatively new plugs, wires, cap, but had just changed thermostat to 150. This group recommended going back to 195, so I did, no change. Put new plugs in - no change. Strange thing is it isn't consistant. One day fine, next day terrible. When it's bad, if I keep the revs up it's not so bad (5sp manual). Could it be fuel filter? Coil? Faulty wires?

Thanks in advance,

MZ

Reply to
MZ
Loading thread data ...

Distributor

Reply to
Bob

This sounds like mine too???

Reply to
MZ

My dads 2001 S-10 got to running really bad like that. Come to find out the catalytic convertor was stopped up. Installed new one, runs like a champ. Just giving you another avenue to research.

Reply to
00castle

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.