freeze92

What information does the computer use to determine the amount of fuel needed at start-up? I still have a terrible starting problem, and I am now completely lost. It is fuel related, because I can spray fuel in the plenum, and the car cranks right up. I have replaced the computer, Prom, MAT, CTS, and fuel pump relay. I have no codes, and my OTC scan tool says everything is in range. I have done all the normal fuel system checks, (pressure drop, set pressure, etc.) and have tried starting with the MAF disconnected. Nothing has made any real improvement. I am not positive that this is an ECM related problem, but I cannot find a mechanical problem with the fuel system. Thanks in advance for any help.

------------------
'89 GTA, Ported Plenum, BBK throttle body, 24lb Motorsport injectors, Jet stage 2 chip, AFPR, no cats and a Flowmaster.
'95 GMC soon to be 383 daily driver w/Howell multi-point injection conversion

GregWestphal

iTrader: (1)

I'm gonna take a WAG and say it's ignition related. With this "terrible starting problem", does it crank for a while before running on its own, or does it not want to crank over at all? If your answer is choice A and your fuel pressure is OK (along with everything else you've checked), then I'd look at the ignition system (plugs, wires, coil, module, cap/rotor). If answer B, then it's either the starter or the solenoid.

------------------
Greg Westphal
'87 IROC 305TPI/A4

freeze92

It does crank over fine, it just doesn't fire off. If I prime the plenum with a little fuel, it fires up instantly. That is why I am thinking I have a lack of fuel flow from the injectors. If it was spark related, it wouldn't fire when primed either, right? Thanks for the input, I am going to get this fixed one of these days

GregWestphal

iTrader: (1)

Maybe the injectors are clogged, or the fuel filter needs to be changed. What are you actually spraying into the intake? If it's just gas, then I'd lean more towards a fuel delivery problem like you're thinking. If it's a starting fluid, then it -could- still be an ignition problem since they are easier to ignite than gas.

------------------
Greg Westphal
'87 IROC 305TPI/A4

freeze92

I am spraying gas into the intake. I have replaced the fuel filter, and I hope the injectors aren't clogged, they are new . The car does run fine once it starts, it just takes a few times trying to get it to start.

------------------
'89 GTA, Ported Plenum, BBK throttle body, 24lb Motorsport injectors, Jet stage 2 chip, AFPR, no cats and a Flowmaster.
'95 GMC soon to be 383 daily driver w/Howell multi-point injection conversion