View Full Version : Nutbar

08-19-2006, 11:15 PM
Mike sent you a pm
Also question for you, neighbour of mine will sell me a 89 Cherokee (whole vehicle) with 4L in it for $400 (blown tranny)
How har is it to put the fuel injection off of this engin onto my jeep (89 YJ 4.2)?


08-19-2006, 11:29 PM
Get rid of the 4.2 and throw the 4L in. I had the 4.2 and it's garbage.

08-20-2006, 12:23 AM
You don't want the 87-90 Cher 4.0 they had lots of little problems plus they never put that 4.0 in the YJs so the some of the parts are not direct bolt in's and the wiring for those 4.0s is a nightmare.

You want to use the 91 to 95 for direct bolt in stuff and the 91 and newer is a much better system.

As far as the running bad and stalling when cold probably needs some adjustments with the carb.

and Chris the 4.2 is not a bad engine it just has a few problems that can be addressed and when kept tuned properly they are quite torqy.

08-20-2006, 03:52 AM
I might give you a call in a couple of days and get you to do that bypass on the carb that you were telling me about.
I think that this has been part of the problem with it stalling while wheeling.
PM me on how much to change the wiring on the carb


08-20-2006, 10:30 AM
I was told if you took the crank out of a 4.2 and put it into a 4L you would have a stroker. Or is it the other way around.

08-20-2006, 12:38 PM
You use the block, head, and pistons from the 4.0 and use the crank and rods from the 4.2 and you end up with a 4.6L inline 6 and from what I have read about this combo using the Chrysler fuel injection (91 and newer 4.0) and a bunch of the bolt on performance, ie header, exhaust, larger throttle body, chip, and 4.0 performance cam, you can get about 300+ hp out of it.

08-20-2006, 12:53 PM
So I can use the engine out of my '89, or should I look for a newer one ? Or see my heap and buy something that's worthwhile.

08-20-2006, 01:03 PM
The 4.0 blocks are pretty much all the same save for a few acc bolt hole castings the cyl heads though are quite different 87 to 90 (renix injection) 91 to 98 (chrysler injection) 99 to present (chrysler injection + distributorless ignition) all can be used for the 4.6 combo just there is not very many performance upgrades for the 87 to 90 Renix stuff and you can't use the Chrysler style intakes on the Renix head (the intake ports do not match properly and will cause intake leaks) the 91 and newer cyl head flows much better than the Renix stuff so greater performance potential.

08-20-2006, 01:20 PM
Thats what I was going to say [16]

08-22-2006, 09:43 PM
Ya Mike speaks fluent jeepanese