I have just installed my Engine, Transmission, ECM and Engine harness from a 1991 Pontiac Firebird Formula in my 1956 ****** Pickup. Used an EZ-wiring harness in the cab.

When I turn the ignition to run the fuel pump does run for a few seconds, when I crank it, it will not start but with a shot of staring fluid it starts and runs.

Even after I have started it with starting fluid and the engine has run till hot, after turning it off it will not restart.

Could someone give me an Idea what to look for? In searching the Forum I see lots of information on earlier TPI systems but not on mine.

Randy

 

Did you bypass VATs in the ECM's chip?

The other would be low fuel pressure, but usually that only affects cold starts.

RBob.

 

is there voltage at the injectors while trying to crank?

 

There has to be because injector voltage because if I spray a little starting fluid on the filter it starts and runs.

 

yes I had the VATS bypassed

 

This the point I am at, there is a tilt front and dump bed.

 

Sorry, I misunderstood what you where saying. thought you meant it would only run on starting fluid.

Does the engine run and idle correctly once running?

 

Yes it runs and Idles fine

 

Only thing I could think of would be the voltage source for the injectors while cranking, if they are connected to the switched 12v source that is not hot during crank?

 

So then as soon as I let go of the key the injectors then get voltage, have to think about this. Thanks for something to ponder

 

You could borrow a noid light set from the local auto parts store or just use a 12v bulb. Disconnect a fuel injector and connect the noid light or bulb to the leads inside the connector. Crank the motor and see if the noid light or bulb lights. It will not be bright but should flash as you crank the motor.

 

I'd also do a leak down test on the fuel pressure and check to make sure the fuel pump is getting voltage during cranking and what the pressure is during cranking.

 

This, I've seen it more then once. You can check it easily, turn the ignition key backwards to the accessory position. If the injectors have +12 volts they are on the accessory position of the switch. Which goes cold in the cranking position of the ignition switch. This is the reason the radio turns off during cranking.

RBob.

 

You nailed the error in my ways ! ! ! !


When I was doing my wiring I used a Hot In Run extra lead from my EZ-Wiring harness, That particular lead was not hot in start.


Thanks for thinking this through for me.


Randy in Colorado

 

I would also like to thank all of you that have made suggestions. Took my rig to the muffler shop and got the new engine all connected to the exhaust system I had with the old 350 SBC.

 

Good to hear you got her starting correctly, glad I could help!