Mopar MPI kit or 4.0L MPI Engine Swap

[jeepwanabe]

1044164

Having read this article:



http://www.4x4wire.com/jeep/tech/engine/fi40swap01/



I am considering this approach and wanted to know what the board thinks.



Right now I have an 83 CJ7 I6 (258) which is Carbureted (just bought it). I have been considering putting in a Mopar MPI fuel injection for better performance and gas mileage. However, after reading Robert Hyde's short article on Swapping in a 4.0L MPI Engine I've been thinking this might be a better way to go. For one, the cost is a factor. Robert did his full conversion for less or about the same as a Mopar MPI kit. There is a shop near me that works only with Jeeps and they charge 3500.00 for a Mopar MPI installation. Robert did his entire conversion for $1762.00. Of course it all depends on the 4.0L engine cost and Robert didn't mention the condition of the engine he bought but I can't believe he would do all that work with a engine with high mileage or poor condition.



Right now my I6 is in pretty good condition but I'd like to get better performance out of it. I believe the MCU is retarding the performance on this jeep. Anyway, if I have to spend the amount of cash (2000.00 to 2500.00 or more) for the Mopar MPI it seems the better value would be the 4.0L swap which would include the MPI.



I'm quite a beginner in the Jeep world so can I get some feedback on this from all the experts we have in this forum?



Thanks in advance,



Bill [addsig]

 

[jprtroy]

1044570

Sounds like a coin toss. I know the 4.0's are peppy engins, my friend has a 95' YJ, and it runs circles around my CJ-5 (with the Mopar kit) My set up though on my jeep is for rocks. With 4:10's lockers, 33" BFG's T18 w/ granny1st, it doesn't go any faster than 63mph down the hwy. I can change that by swapping in some 3:73's or replacing the 33's with 35's (nother story) Don't get me wrong, the mopar kit is the best thing I've purchased for her since I got her back in 82' She has way more "poop" now, and the motor doesn't "chug & pop" like a regular 6cyl anymore! Doesn't stall on the trail either! (big plus)way

I guess your deciding factor will be the cost.

Good luck with your decision!

[addsig]

 

[dadare]

1064124

Just my opinion, but I put a MPI kit on my 258-'83 CJ7. It is a pricey kit, and be forewarned if you are doing the installation yourself, the instructions are lame with no wiring schematic or anything. You'll figure it out though and it is a nice addition. But, and a big butt, if I had it to do again.....and now confident I could do it.....I'd buy a decent used 4.0L HO and replace the entire motor. If going this route, there's a lot to know about other parts you'll need etc. Find a website of folks who have done this and make a list of parts you need such as the harness, computer, fuel pump, etc. and when you go barter at the junkyard, make sure you get it all.

Good luck.[addsig]

 

[Snitty]

1064134

either way... you're gonna have to mess with wiring, computer, fuel pump, and such. I think it would be much better to replace it with a newer, more powerful motor. and as i suggest to anyone that will have the right parts... get a 4.0, and use the 4.2 crank and connecting rods in it... that way, you'll have yourself a 4.5... can't go wrong[addsig]

 

[Jeff_C]

1064261

I have a 1990 YJ 4.2L. Intalled the MPFI $2100. Year later rebuilt engine bored .030, installed 4.0 Head $1400 and Gibson Header with custom crossover pipe because the Gibson didnt come with an O2 plug $120. As long as it was torn apart I put a new stock clutch in $165. A few dollars here and there for bolts, new engine mounts and primer and paint for the engine compartment. Add it up and you could probably find a 4.0L to swap in for less, but will it be rebuilt?

My Jeep runs good and has more power then it did before. With all the money and work I'd hope for more but Im satisfied with the performance. I wish I could check the HP without having to pay a shop to hook up.[addsig]