I'm planning on doing a 4.0L swap in 2-3 months, and I'm on the hunt for a good used engine. My best option so far is a 1998 TJ motor with just under 100k miles. I'm ready to pull the trigger on it, but wanted to confirm a couple of things with the experts. I'm keeping everything stock 1995 OBD1.
I think I can just use the engine as is. The flywheel is the same, so not problem with the CPS. I might need to swap over a sensor or two, since my 1995 is OBD1, and the 1998 is OBD2. Worst case, maybe I swap out the intake manifold, but this seems unnecessary from what I've read. Is this correct? Am I missing anything???
As a side note, a few months ago I got a complete 1995 4.0L that I can use for parts. Its rings are pretty worn, which is why I'm not using it for the swap. I didn't pay much for it.
To help keep things on track:
0) yes, I want a 4.0L
1) no, I can't afford a stroker right now, unfortunately
2) no, I don't want to keep the 2.5L - it doesn't work for me. That's great if it does everything that you need!
3) no, I don't want to do an SBC, 4.3L V6, Ford 302, or 4BT. All very, very interesting, but that's not where I'm going right now.
BTW, buying a used motor is definitely "Buyer Beware"
...I'll add a funny (sad?) story about trying to buy a 4.0L engine from a relatively local used Jeep parts dealer. I talked to him for a couple of weeks via email about a 1994 YJ engine with 110K miles. He sent me a picture of the engine in the Jeep - it was an automatic Jeep, as you could see the transmission dip stick. He said it was a complete engine except for the AC compressor.
He brings it to me on Saturday. First, everything except the timing chain cover was stripped off the front of the motor. The exhaust manifold was cracked. The fuel rail was removed. I did a leak down test on it, and it was pretty bad. Every sensor was broken - oil pressure, temperature, etc. Basically, it was a worn out boat anchor. And it wasn't the engine that was in the picture. The one he brought was out of a manual transmission Jeep, as it still had the clutch and pressure plate installed.
He was either trying to scam me or was just a disorganized mess and didn't know what he was selling. In either case, I won't be giving him any business. And no, I didn't keep the engine!