well i switched my 85 tpi over to speed density and i have a problem, i believe my problem is in the map sensor or map sensor circuit but im not exactly sure. i get no codes (except 12 of course) the truck starts on one crank then immediately dies, it does this whether the map sensor is hooked up or not, i was too tired tonight to investigate further but tommorow i will grab the multimeter and investigate further. anyone else have the start then die problem?

 

forgot to include that giving it gas does nothing, in fact it almost dies faster. this leads me to believe that the fuel injectors are not getting signal from the ecu. and that i should really stop thinking about it or i will never fall asleep. should have left it maf, at least it ran...albeit poorly at times.

 

do you have a laptop and an ALDL cable? would be interesting to see the sensor values on one monitor (much easier work than with a multimeter)

sound a bit like a VATS that blocks the system. Do you have a custom chip in the ECM with disabled VATS? if not, thats your problem

 

it was supposed to be a custom 305 sd chip with vats disabled and so on, i will check

 

problem solved, thanks god for multimeters. somehow and i have no idea how i managed to swap the injector ground (pin bd7) with the map sensor 5v output (pin ba4) they are both black/white so i can see how i would have mixed them up but i did the harness one pin at a time but whatever all is well. one of these days when i get bored i will do a write-up on the 85maf to 92sd swap as i found the others not to my liking, not that i dont thank the writers for giving the information.