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trouble starting after topswap/build

M

MrClean

New member
having some issues starting the car. build is xp cam, ls6 springs, headers,ported lim, zzp s3 ic, 42# injectors, ported blower ported tb, lq4 maf. heres a vid of what happens when we crank it. we have spark, fuel, no vac leaks. we have an idea of what might be wrong but just trying to see what others have to say just in case we over looked somehting

video


 


Whats the PCM tuned for?

Not sure how you can check for vac leaks without the motor running.

Have you done a compression test yet?

Have you tried giving it gas to see if it starts?
 
the tune is fine, and when cranking we watcheed the MAP table and saw pressure. i have not done a compression test, but that will be something i do tomorrow. or thurs. the values for the injectors and maf are correct
 
That doesn't mean you dont have a vacuum leak.

What gasket did you use between the lim/core/s/c?

If you have spark, fuel, injector and maf tables are correct then all that could be off is the cam timing.

Have that golden picture? (timing dots lined up)
 


Let me explain a little more...

1st- PCM is set to stock 99 L67 file w/ LQ4 MAF and 42.5 scaled on the injector table

2nd- yes there is spark but timing is off so bad smoke is coming out the valve cover which leaves me to believe the exhaust is exiting partially out the intake valves. It gives a loud backfire after awhile of cranking. During firing it hits a dead spot every time it goes through all 6 cylinder and lands on one. (hear the video) Sounds exactly like having timing retarded too much.

Scan shows 10* timing exactly when cranking across the board.

3rd- There is vacuum showing on the scan but this does not eliminate all vac leaks I know.

4th- Fuel pressure is 42ish when cranking (adjustable regulator)

5th- Coil packs and wires have been checked and are installed correctly.

BTW yes it was flooded after a while but holding the gas to the floor will clear this out which we did and tried again.
 
so we tried my stock l36 tune with maf table, injector table, and adjusted timing. still no go. it sounds mechanical, and i know i dont have the golden pic of the timing set lined up, but im am 99.9% sure it is lined up. i want to exhaust all options before pulling the motor and checking.....
 
Not questioning your abilities but having it misaligned somehow without even knowing it maybe the problem. It sounds EXACTLY what the problem is. You seen the guy with the key ways installed upside down. I guess you don't know unless you done it. Never thought stuff like this could be put on wrong.
 


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