TBI issue
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quaddriver
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- Ed
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- 1990
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- Chevy R2500
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- The big one
you can borrow 'noid lights from advance nd plug them in and see if you get flash. If not, then suspect wiring from the ECM and if not, suspect the quaddrivers (GM owes me big money) in the ECM. ECMs are cheap.
If there is flash then the injectors themselves can be bad (but both at once?) or the on board fuel pressure regulator bad. This of course is assuming you have 9-13lbs at the TBI when key on/cranking (yeah, you have to make an adaptor to hook up and test)
it just dawned on me, I shot this same problem for someone in an S-truck. It HAD fuel at the tbi and it sorta dribbled something, but it was the pump in the tank (1 year old autozone junk) it would start up on the key in start, and almost immediately die. quickly cycling the throttle would get it to run sort of horribly bad.
If there is flash then the injectors themselves can be bad (but both at once?) or the on board fuel pressure regulator bad. This of course is assuming you have 9-13lbs at the TBI when key on/cranking (yeah, you have to make an adaptor to hook up and test)
it just dawned on me, I shot this same problem for someone in an S-truck. It HAD fuel at the tbi and it sorta dribbled something, but it was the pump in the tank (1 year old autozone junk) it would start up on the key in start, and almost immediately die. quickly cycling the throttle would get it to run sort of horribly bad.
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circuitguy
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- BIG-C
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- 1987
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- GMC 1/2 ton Stepside
- Engine Size
- 350 / 5.7
Might have a bad oil pressure sensor on the side of the block above the oil filter. This sensor will turn on the fuel pump during cranking/starting once there is oil pressure present. This is a common problem for the 87.
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cods
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- Cody
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- 1987
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- R10
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- 350
weeks later and after trying everything under the sun, and without spending more money on non-performance parts im going to say f it. being built into a race motor as we speak so bye bye daily driver lol. anyways, I appreciate the help from everyone. my advice to anyone who jumps onto this thread is: if your tbi is running well and has minor problems, keep it. if it is having major issues like mine did, dump it. it's almost the same price to go carbureted and is a lot more reliable. there's a reason why GM quickly funded to improve the fuel injected motors and abandoned the TBI & TPI after abt a decade.
