Rough idle/misfire

firecadet613 · February 25, 2003

When its butt ass cold out in the morning and I fire up my truck it will idle a little rough while I let it warm up and twice now its set off the check engine light for a misfire. It's had all plugs and wires changed in the past two months, any ideas?

CMNTMXR81 · February 25, 2003

95's = "Spider" Most likely clogged.

firecadet613 · February 27, 2003

Hey Lane my gas milage also hasn't been that great, but hasn't been all that bad either. Probably will replace it pretty soon here, that should solve my problem right? It'll hit 100,000 miles on it later today or tomorrow.

Joe

CMNTMXR81 · February 28, 2003

Well, 4.3's are pretty thristy anyway. But the CPI engines are notorius for having clogged tappet valves in the "spider". If it's not to bad, it can be cleaned, if it is too bad, it needs to be replaced. I haven't looked into the cost of one lately, but back when they were a frequent service item, a new "spider" at the time was around $400.

This is pretty much the same as a clogged fuel injector as that's essentially what the "spider" is. So unclogging it will improve idle, acceleration, and fuel economy.

firecadet613 · March 1, 2003

Well I'm getting about 15mpg in town so I don't think its to clogged, I've heard some really bad horror stories about them on other websites. What should I use to clean it out? Just toss some of that BK44 in my tank? I have a bottle of the GM Top End Cleaner in my garage right now also....

Joe