99 yukon 5.7 vortec motor put in a 96 chevy 1500

[fly-esr]

I put a 5.7 vortec out of a 99 gmc yukon in a 96 chevy 1500
i am having trouble getting it to start
for some reason the spark isn't getting to the plugs
i was told the security ignition on the yukon is not in the 96 and would keep it from getting the spark
i am not sure if this is true or if so if i can by pass the security setting
i have the computer and wiring out of the 99 yukon in the 96 chevy 1500
any help would be appreciated
thanks

[bighaas79]

Use the original pcm and wiring out of the 96 and you shouldn't have any issues.

[clinebarger]

I agree with bighaas, But I would try just the ECM first. The Passlock should allow the engine to start for a few seconds...Then die.

[bighaas79]

Originally Posted by clinebarger

I agree with bighaas, But I would try just the ECM first. The Passlock should allow the engine to start for a few seconds...Then die.

I was gonna suggest just the pcm at first but without looking at the pcm pinouts I wasn't sure if there were any differences. You really aren't out anything by trying just the pcm however. Couple minutes of time i suppose.

[fly-esr]

the motor i took out was a 4.3 v6 and i know the wiring won't work because its different when it goes to the spider injectors but i have no clue about the computer either

[bighaas79]

Ahh thats a little different issue then. I was under the impression you were going from 5.7 to 5.7. Might have to have the security bypassed or take the vats system out of the donor truck.

[fly-esr]

thats what someone suggested but i figured i couldnt do that because where would the vats hook up to ? the 96 wouldnt have the right hook ups
i was thinking of trying to get a wiring harness out of a 96 with a 5.7 and the computer also