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

 

Well like you said the opti is sync'ed to the Delteq and the coils are arcing. You've got fuel pressure so you've got fuel and spark so I wouldn't say the opti is the culprit. Try looking at injector fuses. Is the opti timed 180* out? Firing on the wrong strokes?

 

How could the opti can be timed 180degree out if its driven by the cam pin.I taught that there where only one way to install it?

 

Just something that you should double check, if you havent already, is the valves. If their too tight it will crank but it wont turn on. Since you mentioned that its a crate motor, it should be ready to just turn on but you might just want to double check.

 

Well my Chilton (Haynes) manual says to time the opti by moving the slot/pin/key to the 9:00 position with #1 at TDC. It being a 4 stroke, it's possible it was on the exhaust stroke when he installed it.

 

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...

 

Is it simply a matter of worn out injectors? Or were you just testing on the pigtail?

 

I ve tested the injectors and i got 14ohm(should be between 11 and 16)so they are good.They are also brand new.


I ve tested the pigtail and get the positive signal but not the negative pulse signal so since i dont have the signal,the injectors doesnt open.