Best Fuel Injection for a 258

[hbabler]

What is the best (cheapest) fuel injection system for the 258? I am getting ready to replace the head with a 4.0 head and I was planning on running the carb for awhile until I could get the parts together for a 4.0 fuel injection swap, is a 4.0 FI swap the best way to go I am kind of wary of Chrysler electronics due to an XJ that owned. Or could I do a TBI setup off of a gm v6 or something similar, I am much more comfortable with GM electronics as I have done other fuel injection stuff including some TBI stuff on an IH, I am stumped as to which way would be the best way to go on this one. I already have a HEI distributer so can I just modify it to be controlled by the computer? Would I see any real gains going with EFI over TBI? The TBI is much simpler in my opinion, thanks for the thoughts and help.
Hudson

[Bill usn-1]

The MPFI is a nice system but it was designed to meet the increasing emissions requirements. You won't really see much of a difference in overall performance between the 2. The MPFI does have a little better off idle accel/throttle response due to the fuel sprayed right at the intake valve.

MPG's kind of comes down to tuning.....
Which leads us to the next point.
there are add on boxes for the MPFI that can help with tuning but there's not much for the chrysler stuff.

The GM...as you know is well hacked and lots of tuneability should you make mods or have other than a stock engine.

So either grab the entire 4.0 system with the head and wire it up and run it as is or bolt on a TBI system just like you did with the IH and do what you want to do with it.

Yes the HEI distr can be used, the factory duraspark is probably easier and just as good. Just head back to the binderplanet and look in the FAQ in the injection forum. Most all distr options are shown there.

[Stuka]

There is the Howell system, which is based on a GM TB as I recall. It is CA smog legal as well if that matters.

Putting a 4.0's EFI on a 258 is more involved than just bolting on the intake (Which will hit the brake booster). The 4.0 needs a cam position sensor, which the 258 is not setup for. It can be put on, just one more thing.

But it should also be noted there was more than one EFI system used on 4.0's. There was the original Renix, which I have a lot of experience with. Its actually a very easy system to swap, but can be a bit touchy to get tuned just right. And as far as I know, there are no ECU tunes out there. Lot of people hate it because its more difficult to understand.

Then in '91 they switched to the Chrysler system (4.0 HO). This was more or less the same system that was used for the life of the 4.0. Few changes later on that the TJ's got (Maybe very late XJ's?) which used a curved intake, which WILL fit in an FSJ without brake booster interference.

I have been really trying to think of what to go with in my J10. I actually really like the Weber, but EFI would be far better for the massive altitude changes I have to deal with (1000ft up to 9600ft). But if I do sway, it will be the whole 4.0, block and all. Just because its a lot easier as I will be needing an engine anyway.

[carnuck]

I use the '91 to '95 XJ harness and computer. As long as it's not OBD II, the Mopar based stuff is better than they put in their own rigs.