Ive done a major tune up, replaced starter, distributor, and alot more... The car cuts on when i give it gas and sounds decent but the minute it goes in drive or reverse its a wrap... Immediate stall out... Ran a basic diagnostic and multiple misfires... Anybody out there with a favor in them I need advice.

 

 

Have you changed the pcv valve? Sprayed out the throttle body?

 

How many miles on the car? Does weather make any difference? Major tune up includes cap and rotor, did that get done. LT1's NEED good wires and they need to be routed correctly for them to last. Same goes for the cap and rotor..... AC Delco / Delphi stuff only for these two items. A lot of aftermarket caps don't seal well.

It the opti vent harness (vacuum lines running from the intake, to the dist., and intake elbow to the dist.) is good shape, they need to be, or moisture gets in there and ruins the optical sensor.

Also Opti spark electical harness, make sure that is in good shape with no corrosion on the pins. It's a 4 wire harness about 14" long, and runs down the right side of the intake manifold right to the opti.

Coil wire (on coil) terminal corroded?

 

Spark plugs ? ( is it burning oil ? )

Vacuum leaks or damaged / broken vacumm devices / sensors ?

Un-plugged or damaged / broken electronic devices / sensors ?

God bless
Wyr