Hello all.
I've got a '92 Sonoma GT w/ 118K miles. The truck started running rich a while back (maybe 500 miles). I removed the EGR valve and the pintle would stick open when depressed. I sprayed brake cleaner in it and pressed the pintle down and twisted it with a torx head. After a few times it seemed to work correctly so I put it back in. That helped a LITTLE bit. I replaced the cap, rotor and wires. I couldn't really tell if that helped. I ran some fuel injector cleaner through it (Gumout) and that didn't help. I replaced the O2 sensor, that didn't help. I then got the 43 code indicating the ESC. I had just replaced the plugs (the plugs on the drivers side were all black, the ones on the passenger side were all fine...) but figured I may as well go for the ESC as well, so I replaced that just now. It seemed to run a little better, but I only took it for a quick spin just enough to warm it up a bit and check it out.
Symptoms -
Running rich (a little black smoke from the exhaust)
Seems to "misfire" from 2KRPMs (falls flat on it's face)to about 2500 RPMs.
32 and 45 codes at first.
After replacing the wires, plugs, ESC, Cap and Rotor the 43 code.
Any ideas? I think the main clues lie in the codes, the black smoke and the fact that the three plugs on the drivers side were black.
Thanks in advance
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Incase you didn't know - It's the 4.3L Vortec "W" code V6, CPI.