MY BROTHER PURCHASED TWO 89' FIREBIRDS, 1- 350 TPI THE OTHER 305 TPI. BOTH HAVE THE SAME NO START PROBLEM. THEY WILL NOT START UP WITHOUT THE USE OF STARTER FLUID SPRAYED IN THE INTAKE. CARS WILL RUN FINE OTHERWISE. FUEL PRESSURE,SPARK,OIL PRESSURE ALL ARE FINE. ANY HELP IS APPRECIATED.

 

HAVE YOU CHECKED TO SEE IF (Oh, I'm sorry. I'll stop yelling now.)

Have you checked the fuel pump on startup? The pump should run a prime cycle for two seconds when the ignition is first turned on. If this does not occur, the relay may be a problem. In that case, fuel may not be pumped until the engine has developed about 7 pounds of oil pressure. That may explain why it starts and runs with fluid, but not on its own.

 

When it won't start, get a noid light (found at Pep Boys, Auto Zone and Harbor Frieght) and check for injector pulse during the "No start". If you DO NOT have injector pulse during the No Start, but it will fire up and run with starting fluid, put an ignition module in it.

 

I DO HAVE PULSE TO THE INJECTORS, AS WELL THE IGNITION MODULE WAS CHANGED, FUEL PUMP PRESSURE IS GOOD. ON BOTH CARS THE SAME THINGS WERE CHANGED AND CHECKED.
THE FUEL PUMP IS CYCLING PROPERLY AS WELL.

 

James,

Hit the "Caps Lock" key...

Anyway, is fuel pressure good with key to "on" without starting the car? Or did you only check pressure once it was running?

 

I'm on the same track as the others. If you need starting fluid, then your not getting enough fuel at start up. If your injectors are pulsing, then its a fuel pressure problem.

With the fuel gauge hooked up, turn the key to the "on" position and see if it builds pressure. Also, what pressure do you consider "good"?

I would also try and find out what the Coolant Temp Sensor is reading when cold. If its off by a few degrees, it can also cause this problem. You can either use a scantool of some sort (even cheap ones will do this) or you can measure the resistance of the sensor and compare it to a resistance chart.

 

Fuel pressure was at 40 with the car off and while running it was at 35. A new coolant temp sensor was also replaced.

p.s. look no caps(what a difference)

 

What else have you done to try and correct this problem?

 

Much easier to read now James...


Go with GMTech's advice, a noid light is about 10 bucks at your local DAP, verify injectors are pulsing when trying to start the engine. It'll take two of you, unless you have a remote start switch to wire up.

If injectors are pulsed a startup, then could very well be there are a few not passing fuel...so then you'd want to get an injector cycler and test them individually.

BTW, does it run smooth and such at idle once it's running?

 

Yes I already ckecked for pulse at the injectors and all were good. The car runs great after it starts. No hesitation, no rough idling.

 

Can anyone help me with an oil pressure question? I have an 89 GTA 5.7L Vortec TPi 5spd. I noticed that my oil pressure drops as engine tempeture increases...it drops to the point where the engine is almost stalling...basically stumbling. Do I need an oil pump or do I need to replace the oil pressure switch again? I changed it last week. Car has good oil pressure on cold start way above 30 on the "not so accurate" oil gauge Any help greatly appreciated.

 

We would be glad to help, if you quit hijacking this thread and start a new one

 

The oil pressure fuel pump switch, and the fuel pump relay are in a parallel circuit, if the pressure switch fails the fuel pump will still run, if the fuel pump relay fails, the fuel pump won't start until oil pressure builds up.
I've done the following because at one time I believed that losing the pressure switch would kill the engine (I didn't have the manual at the time):
Fuel pump relay connected, and pressure switch disconnected - engine starts no delay.
Fuel pump relay disconnected, and pressure switch connected - engine starts after a delay.
I don't know with which model GM revised the fuel circuit from series to parallel, this change is in my '88 wiring diagrams.

If for whatever reason the fuel injectors do not flow, the engine will only run as long as there is starter fluid in the intake.
The ECM isn't capable of disabling the injectors if there is no fuel flow because it has no active why to sense fuel flow, or the lack of it.

 

Sorry, wasnt trying to be rude. New thread posted.

https://www.thirdgen.org/techbb2/sho...34#post2516734