My friend in New orleans just did a LT1 swap in his 87 monte using a painless wiring harness running a 93 ECM with a 94 LT1.
The problem is he got the car running but it would not idle below
2000 rpm (but it automatically goes to 2000)and is giving him a IC FAILURE OR SHORTED light . and it seems to run great like that but will not idle down,and he said today car will not even start at all...
We are waiting for his akm cable to come in ,probably monday.
Oh yeah car has LT4 hot cam , roller rockers and headers being only mods.

Any help would be greatly appreciated,
Thanks.
I will post this on Engine swap board as well.

 

I saw another painless harness do something similiar to that.

That's one reason, I graft oem harnesses when doing swaps.

 

Anybody?
What would cause an Ignition control open or shorted failure?

 

Has he checked the simple things like adjusting the IAC or vacuum leaks? Lots of possible reasons.

 

Yeah I had him go over all that and even plugging off the IAC in case its stuck open.
I also had him contact painless and they told him use the camaro bin because its less forgiving and still no go and still ses code 41.
Now they have sent him some diagnostics to go over on the wiring,he is going to do that this weekend.
Thanks for reply.

 

I meant more.