Alright guys help me out on this one. I have a 1989 Camaro RS TBI 305 5.0. I was having intermittent start problems but that turned out to be the ignition switch, the car sat for about 8 months. Now i just had the throttle body rebuilt, it has a new ignition module, ignition switch, and fuel pump. I am getting fuel and spark. I can start it with Throttle Body Cleaner and it will fire up and run for about 5 seconds this stall out. I am getting a code 34, which is the MAP sensor. I understand that can make it stall if its out it goes refrencing the TPS. What is making it not start though? Im bustin my brain here guys help me out. It needs a tune up, but it did have one before it sat. The rotor is clean the cap is clean. It wants to start it just can't seem to get over the hump. I can keep it runnin on starter fluid but when i stop sprayin it stops runnin. Its getting fire to the injectors because the noid light was flashing like crazy. I need to check fuel pressure, but the noid light should cancel out the ECM being a problem right?
Thanks

 

Low/no MAP readings are whats making it stall if its consistently throwing a code 34. The car may not be running long enough to throw the error at startup, hence not enough fuel. Or, the fueling based off the TPS may not be right.

 

Is the TPS keeping my car from starting though? Im just getting big drops out of the injectors it seems they will fire a nice cone for a second then nothin.

 

The MAP is used during cranking/startup to determine how much gas is needed. If its reading low, the ecm wont give the engine much fuel until it throws a code. If the car has thrown the code 34 repeatedly, then replace the MAP and see if it helps.

Do you have winALDL? That will tell you for sure.

 

I had problems with my TPI car not starting and it was the IAC sensor. If that is malfunction your car will not stay started. Can you keep the car started if you give it gas?

I would also check the TPS to see if it is gone haywire. You can check it with a multimeter. Here is a good article for it. It is for a TPS car but I think it is the same.

http://www.iroczone.com/techarttpsadj.html

 

Thanks AZ i'll check out the article. I don't think its my IAC though, if i crank it and just hand pour gas down the throttle body it purrs like a kitten, no misfire or rough idle really. The injectors just drip a little but if i pour gas down it and have someone hit the gas they can rev up the engine on their own. I am leaning more towards a Fuel Pump Relay or possibly the OPSU. What do ya'll think?

 

Sorry another reason i think it is the OPSU is because if i sit in the car and crank it good and hard a couple of times it will start by itself then stumble and die. But it does seem to want to start a little better once you've built up some oil pressure, which closes the fuel pump circuit and wala!!....i could be wrong though..just thinkin out loud.

 

Have you checked the code 34 out yet? That will cause your problems if the car doesnt run long enough to set a code. Check that first if the ECM is consistently throwing that code. Its an easy fixer if it is the issue with the car. it could be a faulty pump, but the MAP is alot easier to replace.

 

If i disconnect the fuel lines of front im getting fuel to spit, it has a new pump and new fuel filter, the lines are clear so i doubt its the pump. I had gotten a map code once but i had a broken vacuum line, once i replaced that line it hasn't thrown the code again. My problem is that it doesn't want to start at all unless i put gas dowdn the TBI myself or if i sit there and crank it a while. Thats why im wondering if my OPSU is waiting during cranking to build pressure up to 4psi to close loop and run the fuel pump. The noid lights were getting fire so i doubt anything is wrong with the computer, and i have a feelilng its a sensor...its just finding which one. Maybe a fuel pressure regulator, but i have to take my fuel gauge back because AUTOZONE sold me a broken POS so i won't nkow fuel pressure yet. Hope this little bit more of information helps ya'll help me lol. Thanks guys.

 

If you hold the gas pedal down while cranking it will it start and stay started with your foot on the gas?

 

Long story but it turned out to be a partially clogged strainer. I went ahead and replaced the pump just for giggles...all good now. Thanks everyone for your help.