New motor,new parts,no start.Need diagnostic...

[always faster]

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

[jagevileye21]

Which style opti do you have?


If your using the vented style opti you have to line up the cam sprocket pin with the indent on the opti. If you don't it will never start. I had mine installed wrong and it took a few days before I finally decided to check the opti.

The non-vented opti is basically str8 forward.

Good Luck,
Jay

[always faster]

Ok i ve pass all day making some test.

Ive connect all the wire to theDELTEQ and align the spark plug in the motor firing order.All the plug works and in the good firing order.So its good.

Its also firing the no1 cylindre right around 5/6 degree of advance.Soits good.

Since all the "spark" question have been check and clear i ve begin to check the fuel system.

I ve recheck the fuel pressure with a good gauge and a fully charge battery.I got 44psi with the key at "ON" position and i got 47psi when i crank.So its good.

Now its getting interesting.I ve check for injector pulse with a mechanic guy.I got positive injectors pulse on all 8 injectors.So its good.

But all the 8 doesnt have the negative injectors pulse.I did have one blink on the number 7 and 8(maybe this is were the small backfire is coming) but after that and for all injectors,absolutely no negative signal.

This is telling me that my injectors do not receive the complete signal to work(open).

I ve check for cut wire directly from the pin of the pcm and the injectors connector with a multimeter and everything was fine.

I also plug a GENESYS scanner on it.No code.

So what would cause this problem.

Need suggestion...