1990 xj motor into my 90 yj

[drkoots]

The 4.2 in my yj has a bad lifter and lots of blowby coming into my breather, I'm thinking maybe my motor is worn and I should replace it. I already have a good 4.0 out of a 90 cherokee is it easy to swap and what do I need out ot the cherokee. If anyone knows what is causing the oil blowby please give me some advise, I don't know much but I want to learn, Thanx

[Dukes69]

I didnt know a bad lifter could do that. If it is, replace the lifter.

[Old Fart]

Lifter would be unassociated with blowby - that's either rings or valve seats/guides.

Lifters and camshaft _should_ be replaced as a set - YMMV.

[aston]

The 4.2 in my yj has a bad lifter and lots of blowby coming into my breather, I'm thinking maybe my motor is worn and I should replace it. I already have a good 4.0 out of a 90 cherokee is it easy to swap and what do I need out ot the cherokee. If anyone knows what is causing the oil blowby please give me some advise, I don't know much but I want to learn, Thanx

A compression test is easy to do and gives a good indication on the condition of engine internals.

[Davisrats]

this is copied from a post of mine.

The wiring harness from the computer to all the sensors on the engine, coil, and relays is one piece. I unplugged the computer and pulled the engine harness and all. Then I stripped from the front harness what I needed to hook the engine to the CJ. It is now sitting in the CJ and looks pritty good.
I used the XJ transmission, it has the CPS in the bell housing.
It looks small compaired to the 360 that came out. (Got tired of the mileage)

Ron
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1980 CJ7, 4.0, AX-15, 33s
1990 XJ AW4