Engine Swap Old 4.2 Liter with a Newer 4.0 Liter

[tower210]

Idk about a custom tune.

I don’t think the stock Ecu is programmable

 

[ag4ever]

I think somebody used to do piggy-back chips as I recall. Might be someone on jeep strokers that might know.

 

[bigwalton]

Not sure Raymond would totally agree that the 4.0 is not capable of having vapor lock.

”Not capable” is not what I said and a far cry from ”not typical.” What I mean is that you don’t see stock 4L vehicles running around with vapor lock.