Ok i install my new motor last week and week end(thursday/friday/saturday/sunday/monday).As you can all see, i took my time to do it right.

But damn it crank but wont start .Here a the basic info of the car and all the things that i ve tested.

-New GM LT4 crate motor with of course the lt4 intake with all new sensors(o2,temp ecm,temp guage,oil pressure,knock,etc).The motor turn perfectly and the oil pressure goes over the 275 mark on the gauge

-New Accel 32 lbs injectors.Read 14 ohm on the tester wich is good and then tested the opening and they where good.

-Stock fuel pump and stock fuel rail.Took the pressure with the key on "ON" position and that gave me around 35/38 psi wich is also good.

-New DELTEQ system.Just like the manual says.
>Ive tested the module.Put the key"ON",the red led blink and shut off,this mean that the box is working.
>Also tested the opti signal.Crank the car,the led blink 2 times to synchronise with the opti and then stay on.This mean that the signal reach the box.
>Tested the coil.Unplugged every plug wire on the coil than crank the car.Every coil made "arc"
>The coils are mounted on the valve cover and i plugged it exactly like they show it.From the front on the car: 8-5-2-3-4-7-6-1
>The delteq wire cannot be crossed since every connector is different.

-PCM.Tune for the spec of the motor by Ion

-Put a scanner on it.No code.

The only thing that im suspicious is the damn stock opti.I ve bought the delteq billet cover plate.When i install it i remove the rotor for safety purpose but the rotor bolts where way to long and way to small in diameter to only hold the small timing disc.They were hitting the bottom of the opti casing.I add to add 2 washer to each bolt.

So there is fuel and spark but it doesnt start.It crank without a problem and seems to want to fire up but it doesnt.It makes somes small back fire in the exhaust,just like if the timing was off

Feel free to give me some "hints" or advice.I could be wrong somewhere.

Thank you

 

Check the ground to your starter. I had a similar problem when I put my LT1 back in my car. Does it engage the starter? Or just "click" when you turn the key?

 

The starter turn perfectly.The motor too.But doesnt start...

 

I change my pcm with a re-programmed one but forgot to disable the VATS...A friend told me that this could be a VATS problem since i got fuel pressure at the fuel rail but my plug seems to be a little to dry.

Would this make sense?

 

VATS wouldn't be an issue.

 

Still need help

 

Isn't the fuel pressure at the rail supposed to be between 41-47 with the key on.

At least that is what Shoebox's site said

I checked my fuel pressure last week -and it was right around 45 lbs. with the key on.

At 35-38 lbs. -You may not be getting quite enough fuel to fire it up....

 

what if he sprays some fuel in the intake, it would then start possibly? then he would know its fuel related?

not sure if this is do-able but make sense in my mind?

 

Ya you could definitely do that. Just take off your intake elbow and have someone squirt a little bit of carb cleaner into the intake while you crank the car over and have the throttle blades about half open. If it starts up real quick - then you know it is a fuel problem. Note that it will not run for long with the intake tubing off because the air will be un-metered. But at least it can help you narrow down your problem.

This is how I knew my fuel pump went on my grand-am a few months ago. It wouldn't start - but wanted to fire right up after I squirted some carb cleaner in it....

 

Well if you have spark, fuel, air, and timing you should be good to go.

So if the battery cranks the starter and the starter turns the engine and the TB is installed to allow for starting condition, and the spark is reaching the plugs which are in the correct order and pcm is good I don't know what.

You might want to borrow another PCM to see if that is a problem. I know this seems like oversimplification, but the concept is to eliminate all possible causes----which apparently you are doing.

Good luck and be sure to let us know what the problem is/was.

 

unplug your injector fuses and crank it at WOT. i think it may be flooded. careful cuz it could fire up and take off. once the cyclinders clear put the fuses back in and you should be good to go.

 

Tomorow i will put my stock pcm in just to check the easy thing

 

When i builded the oil pressure in the bloc before the initail start up, the injectors fuse was not there to prevent flooding.

What i really sound strange is that i got fuel rail pressure but even after a couple of long cranking with the fuses injectors in,the car doesnt smell gas(like a flooded one) and my spark plug are not really wet.

 

All the fuel pressure in the world won't mean a thing if the injectors aren't firing.

Have you checked for injector pulses or tried squrting fuel directly in the intake while someone cranks it over?

 

Good point ,how do i check the injector pulse?

I ve tried to swap for my stock program pcm but the car didnt start.