Timing is off?, can't figure out why.. HELP!
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From: Pittsburgh PA
Car: 1986 Camaro IROC-Z
Engine: 357 LTx
Transmission: T-56 6spd
Axle/Gears: GM 7.5 10 bolt with 4.10 richmonds
Timing is off?, can't figure out why.. HELP!
Ok, so my engine has been done for weeks now and it hasnt run right since I first started it. I finally got around to taking it to Bryan from PCMs for less and his opinion is that the mechanical timing is wayy off. His theory was due to my Delteq opti spark coil packs that I had installed on my car. So I took the coil packs off, purcashed new wires, msd coil, and ran everything off the stock opti.... The car still runs like trash.
Description of how it runs; Starts rough, you have to feather the throttle to keep it going or it immediatly wants to die, has back pressure coming through the manifold and out the intake, eventually will build up fuel and smell like its running rich if you keep the motor going long enough.
-Now the parts that are not new on the ignition system are the opti-spark which i purchased used and in "good working condition" because i only needed it to send signal to my coil packs, and the ignition module. Now I'm not exactly sure but if those parts were not working correctly I don't think it would send the timing off like crazy??
I'm running the LT4 hot cam kit, LT4 heavy duty timing chain, when I installed the cam I lined up the dots correctly and degreed the cam, it is 1 degree retarted. The lashing on the rockers are not over tightened, i got them snug then went a quarter turn (i planed on going back and adjusting them while the car was running, if it ever runs correctly)
I'm pretty much at a dead end with what to do, this is my first EFI motor build and I have no idea what can be throwing my timing off this much, if it is even the timing thats making it run like this? Could it be anything else causing the symptoms that I stated above? But any help or advice at all would be great! thanks! If you need any more info please let me know
Description of how it runs; Starts rough, you have to feather the throttle to keep it going or it immediatly wants to die, has back pressure coming through the manifold and out the intake, eventually will build up fuel and smell like its running rich if you keep the motor going long enough.
-Now the parts that are not new on the ignition system are the opti-spark which i purchased used and in "good working condition" because i only needed it to send signal to my coil packs, and the ignition module. Now I'm not exactly sure but if those parts were not working correctly I don't think it would send the timing off like crazy??
I'm running the LT4 hot cam kit, LT4 heavy duty timing chain, when I installed the cam I lined up the dots correctly and degreed the cam, it is 1 degree retarted. The lashing on the rockers are not over tightened, i got them snug then went a quarter turn (i planed on going back and adjusting them while the car was running, if it ever runs correctly)
I'm pretty much at a dead end with what to do, this is my first EFI motor build and I have no idea what can be throwing my timing off this much, if it is even the timing thats making it run like this? Could it be anything else causing the symptoms that I stated above? But any help or advice at all would be great! thanks! If you need any more info please let me know
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From: Bethlehem, CT
Car: 1983 Firebird SE
Engine: C5 LS1
Transmission: 6 speed
Axle/Gears: 3.42
Re: Timing is off?, can't figure out why.. HELP!
Have you checked your actual timing? Try retarding it and see what happens. Maybe (maybe) your engine does not want all the advance you think it does.
I had that with my 383/ Super Ram/ 280XFI setup.... took me ages to figure out why it ran so rough. MUCH better now,
Good luck.
I had that with my 383/ Super Ram/ 280XFI setup.... took me ages to figure out why it ran so rough. MUCH better now,
Good luck.
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