I gots all the problems with the 4.2...carb, head, smog, and 180 thou. on motor. should I rebuild the block, chase the 4.0 head down, and buy the new fuel inj. or go with the junk yard special? they offered a 94'-95'ish engine + fuel inj ("everything I need") for 1,800 to 2000. is there any junk yard tricks they could play that I should watch out for? Thanks
That's top dollar for a 5 year old 4.0.
You didn't state the mileage. Better check! Could be 125,000 ++!
If you do opt for it make sure you get the ENTIRE wiring harness, the MAP sensor on the firewall, the charcoal canister, relays, ... everything ...
Yeah, I kinda agree with Jaffer - be sure it includes EVERYTHING if you buy it. For that kind of money, you don't want to be making more than one trip!
How much would it really cost to overhaul your 4.2 and add a 4.0 head? To me, that sounds like a sweet setup . . .
'80 CJ7,258 w/TR,4" spring lift + 1" shackles.
There are so many things that can add more $ to a 4.0 swap - and more come into your head as you think about it. Things like the fuel pump - the junkyard guy probably would have forgotten that, as it's not "in" the engine compartment. Junkyard guys are great - stand there chomping on a cigar, going "Yup, it's got the computer, and everything! Whatta ya say?" [img]/wwwthreads_images/icons/crazy.gif[/img][img]/wwwthreads_images/icons/tongue.gif[/img] Personally I would not do that swap unless I had a complete YJ sitting there to take the parts from as I needed them.
Otherwise, it depends on how complicated you want to get. A 4.2 can be a nice uncomplicated motor with a good carb like the weber or a motorcraft 2100 (I think this is the right number), an appropriate cam, and a good ignition like a GM HEI or a team rush upgrade. If you are in a state where your emissions laws won't allow something like that, then a 4.0 head and the mopar injection is supposed to be a nice combination, and you can buy it new with everything you need, and know you've got it all, and you'd know the price.
Just my $0.0000002.