solarguy

Hello,

New member here with an 1986 2wd Pick-up had since new, 250,000 miles and still going strong. Recently, motor has developed an afterfire on deceleration. I've checked the fuel cut off solonoid and that checks out ok. All vacum lines and smog devices are hooked up and check out as per manual. Has anyone else encountered this problem and what was the solution? Thanks,

Garrett

solarguy

afterfire/backfire when I take my foot off the gas as in coming to a red light, etc.

kyle_22r

sounds like it's running rich or the timing is off.

solarguy

Timing is right on and both cans on the vac advance test good. I also think it's an overly rich condition but sputtering is only heard when de celerating. carb not coming off cruise circut? I

jimbo74

my truck does this too... i think i have it timed too much though... can never find an acurate degree measurement, so i just leave it at like 10* ... probably too much, but it seems to run better there

superjoe83

check for an exhaust leak, the leak will pull in air and ignite the unburnt fuel in your exhaust system

Flamedx4

You might cleaning the air mass sensor, and check the dashpot, it may be shot.