I've got an 88 YJ with the stock 4.2L engine which will someday be replaced but in the meantime I am looking for a cheap FI upgrade since the carb doesn't like hills. Since the 4.2 was fuel injected for a couple years and the 4.0L is similar enough, is there a later model Jeep I can pull the parts from and bolt to the YJ??

Are you in a state that requires smog? 4.0 OBDI and II swaps are very doable and once done will make dropping in a 4.0 later a snap. Complete kits are available $$$$$ or you can source a late model 4.0 donor that will have everything you need. '97 and later is OBDII prior years are OBDI and RENIX all of which will work. Look aroung to see what is available and do some research on the process. Try CJOffroad.com. They have a pretty good forum on this conversion. I recommend to conversion--It will change your life

We do require SMOG testing so either OBD I or II would be good for me. I'd really like to swap in a diesel when the time comes but most likely it'll be a 4.0L.

Thanks for the info...

Since the 4.2 was fuel injected for a couple years....


Not sure where you got that idea, but the 4.2 was NEVER injected out of the factory.

You could take the EFI equipment off a 4.0 (Intake manifold, etc) in the junkyard and put it on your 258 as a low-cost option. There are quite a few parts you need though - not sure if the headaches are worth the savings over just buying it as a kit from Mopar though.

Not sure where you got that idea, but the 4.2 was NEVER injected out of the factory.

I thought I read somewhere that the last year or two of the 4.2 was FI. My bad.