89 s-10 4.3 backfires through tbi until good and warm

checked vacs and she runs strong when it's warm but until then.... she'll backfire and shut down. :banghead: any ideas?

Cool temp sens? Thjinks it's to cold outside.Maybe.

checked vacs and she runs strong when it's warm but until then.... she'll backfire and shut down. :banghead: any ideas?

When is the last time you did a tuneup and changed the cap and rotor?

tuned it up about two months ago,cheap champion plugs though. where would i locate the temp switch and wouldn't it rev higher it it thought it was cold out ?

also it ran fine for about a month

tuned it up about two months ago,cheap champion plugs though. where would i locate the temp switch and wouldn't it rev higher it it thought it was cold out ?

Not always at all.

What did your tuneup include?

Do you know how to set the base timing?

my 86 was backfiring thru the TBI on the upshit. turned out to be spark plug wires.

base timing? you got me on that one ( haven't got a clue) I just want it to run for about six months while a 350 is being built for me

You have to remove the brown and black timing wire from PCM under the glove box carpet area, then set the timing to zero, and then reconnect the timing wire again and reset the computer by pulling the negative battery cable for 10 minutes.

being a newbie please don't think I'm COMPLETELY STUPID but.... set the timeing to zero ie timing light? under the hood ?:eek2: