Looking for a few suggestions. Swapped in a 3.4 inplace of the 2.8. Got everything reassembled and it doesn't fire. Sprayed carb cleaner down the intake and it fires. Checked the fuel pressure and it is 42 psi. Checked the 3.4 injectors and they are all 12.6 ohms.

Just looking for a few suggestions of where to go next. Thanks in advance.

PaulC

 

Timing correct?

 

It will run if I spray enough starter fluid down the intake. Thanks for the reply.

PaulC

 

Are your injectors fireing when you crank it if not you wont get fuel for the engine to run . Double check your wireing and make sure everything is hooked up and tight at all connections .

 

cold start injector?

 

did u have to change your trans out of ur car to something different or was ur 2.8 trans able to bolt up to ur 3.4?

 

Mine has done similar twice and I just had to let it sit a few days then it started fine. Plenty of fuel and spark and run on either but no run.

Also each time it was after having computer battery n all junk unhooked then back.

 

What injectors are you running , what intake settup , and is everything plugged up and tight ?

 

Finally got back to working on the F-bird. Here is what I got:

Ran fine before 3.4 swap. Prior owner bypassed the ignition switch with a push button on the dash, but key has to be in the run position.

-Swapped in '95 3.4 and fuel injectors.
-Has correct fuel pressure.
-Has 11 volts going to fuel injectors, and power going to the ECM.
-Motor turns over but doesn't fire.
-If I spary carb cleaner down the intake manifold and then start it, it will run until the carb cleaner is burned up.
-Security light is lit when key is turned on.
-Checked wiring connections that were disconnected during the swap.

Starting to wonder if it has something to do with the ECM or security stuff. Thanks in advance for the help.

Yes the stock tranny bolted up to the 3.4 motor.

PaulC

 

How long has the tank sat? Crappy gas....?

When it runs on the carb cleaner, does it sound alright?

 

IIRC the security light should come on for about 3 seconds when the key turns on. if not I can tell you how to bypass VATS.

 

^^Yup sounds like a vats problem. The security feature is cutting off fuel to the motor so you cant start it...bypass the VATS and see if that works.

 

If you have good fuel pressure, how is the fuel pump being cut off? or do you meant the injector pulse width is shut off?

Anyway, you need a "noid" light. It's a little special light bulb that plugs into the injector plug and then when you crank it you should see the light flashing. If it doesn't flash then your injectors are not pulsating, and then no fuel. You can get this light from the auto parts store or make one from soldering wires to an old 1157 light bulb.

Let us know what you find out.

 

I agree. Look up "VATS bypass", it's been covered a lot of times here. Just need a simple multi-meter.

 

All right. Finally after:

-Checking wiring, fuel pressure, injector resistance, power to the injectors and computer, and getting a key that wasn't screwed up I took the plunge and ordered a set of rebuilt injectors.

It runs good now. They looked a little dirty but now some little things and I can drive it. Thanks for all the replies.

PaulC

 

Are you using the 2.8 injectors, and if so how old are they... my modded 3.4 wouldnt start with the 2.8 injectors with out the carb spray and I had to upgrade to 19lbers. I think the 2.8s are 15lbs. Not 100% on that tho.
Edit::: Just reread post about 3.4 injectors. Scratch idea