i have a 92 b2200 f.i. 5spd. does anyone know if a bad mass air flow sensor would cause my truck not to start in cold weather (45 f or below)? above 45f it will start but hesitates when i try to drive. below that it might start, but only run for less than a minute and then won't start at all after that unless i let it sit overnight. any help would be appriciated. thanks.

 

It can,try cleaning the hotwire. A cold engine requires a rich fuel mixture to start and run properly so the fuel pressure is bumped up on cold start til warmup. A vacuum leak/bad ECT/fuel pressure regulator/etc can cause what you describe. I would run a fuel pressure test on it before replacing parts. Even excessive carbon can cause what you describe.

 

fuel pressure is good, can not find any vacuum leaks, had computer rebuilt. how would i check fuel pressure regulator and where would i find the carbon build up. truck ran strong before this problem, would like to save it if i could.
thanks.