Problems after engine swap

[M05y]

I searched and can't find anything on this. Hoping someone can shed some light on this.

I have a 2006 Grand Prix with the California smog pump. The engine died. My mechanic replaced with with a salvage engine from LKQ. He said it is out of a buick. The engine does not have the smog pump, idk if this would cause any issues besides a check engine light.

I picked up the car today and everything runs perfect. Normal driving there is no issues, except for one. When I floor it in first gear, and it is nearing redline to shift into second, it gets to about 5500 rpm and then just shuts the engine off. I restart the engine and everything is normal. No check engine light.

I took it to the mechanic and he rode in the car with me while his scan tool was hooked up and I duplicated the issue and now codes were thrown. He is looking into what it could be.

Has anyone here experienced this before? It seems like the computer isn't happy about something and just shuts off the engine. Do Buicks have a lower redline? Could that be throwing the computer off? Where would we start looking if it isn't throwing any codes?

 

[bandook]

Loose ground? Or maybe something with the security, probably not likely just guessing. I'd double check grounds. Make sure the one that's by the ICM is hooked to it's idler bracket. Though, not positive 06's have one there. Maybe fuel pump?

 

[BillBoost37]

It's the same engine. He should have swapped over the rear exhaust manifold (which would have retained your smog). Otherwise they are essentially identical. Nothing should be shutting it down like you are saying.

I have done a lot of swaps between the various named models and the base engine is identical once you pull off accessories. This assumes a series II is replacing the same.