CJ7 add on Fuel injection system

[j0114]

I have an 86 CJ7 inline six AMC 258 i6 / 4.2l with a 5 spd Transmission currently running a weber carb. I think its running a tad rich but nothing extreme and I get fair gas mileage considering its a jeep and im running 33-12.50 MTR's

I only know of 2 kits for the fuel injection conversion
-------kit 1-Howell throttle body fuel injection kit for 6 and 8 cyl AMc engines, for my jeep this kit runs 1200$ basically from the 4wd.com catalog

--------kit 2- Mopar Multiport fuel injection kit for AMC 258 i6 / 4.2l AMC 258 i6 / 4.2l 6cyl Engines
this kit is 2750$ basically.

I have been told by other jeepers the mopar kit is heads above the howell, granted it is a bit over double the cost, but I want this to be done right if I got this way, I didnt rebuild my jeep I know some will slam me for not building it myself but i found the year color scheme etc and built almost exactly the way I wanted and for the condition and parts on the machine I got I feel a very good deal,

So can anyone help me shed some light on this mod, I would expect better HP/torque possibly and better fuel economy. I have had zero problems with my weber as I know some people have, issues with the carb is not the reason for my interest in this mod,
Id love to hear opinions on both sides for it, Even if you think is stupid and over priced thats fine just tryn and backup your post with some facts or personal experience.
Thx
lots fellas

 

[j0114]

also if you could let me know how big of a job this would be that would be great also

 

[CJ]

~~~ I didnt rebuild my jeep I know some will slam me for not building it myself ~~~

No one here will do that (or I'll take care of em' )... There is nothing wrong with buying the CJ you like in whatever condition it is in.

You might want to add the Holley Pro-Jection system to your list. I have that on my CJ.

Search Results for holley pro jection - SummitRacing.com

The reason the Mopar kit is so expensive is because it is a multi-point FI where the others are throttle body types.

 

[j0114]

I will do some more research and come back with more questions,

let me ask this if I may sir,
are you happy with the kit you chose? and is the Multi port produce alot more power or is it more efficient so to speak? I just want to do this mod once,
Is this something you can do in your own shop or do you need to be a professional mechanic to do it, I mean I would hate to ruin 2-3k in parts because i tried to save install charges which I am sure isnt cheap.
But I got a great shop close by, a trustworth guy , he is into jeeps from top to bottom rebuilding, rock crawling and he knows his stuff and is fair priced in my experience so far, my only complaint with him is he tried a bit to push the lift he has on hand on you as opposed to the one you want is an example i could give but does good work at a fair price up to now anyways,

Did you install yourself, if not would you mind telling me what ball park the install cost?

 

[AussieCJ7]

Why not grab the 4.0L and all EFI system from a XJ and use that same as mopar kit at a fraction of price just a little more research and work

Mopar kit is just a OBD1 jeep set up put in a kit to make it simpler but given you only need to interface 5 wires to start an obd1 system and about 7 or 8 to make it run right its not that hard to do yourself

4.0L head flows a bit nicer and give a bit more grunt

 

[CJ]

~~~ are you happy with the kit you chose? and is the Multi port produce alot more power or is it more efficient so to speak? I just want to do this mod once,
Is this something you can do in your own shop or do you need to be a professional mechanic to do it, I mean I would hate to ruin 2-3k in parts because i tried to save install charges which I am sure isnt cheap.
But I got a great shop close by, a trustworth guy , he is into jeeps from top to bottom rebuilding, rock crawling and he knows his stuff and is fair priced in my experience so far, my only complaint with him is he tried a bit to push the lift he has on hand on you as opposed to the one you want is an example i could give but does good work at a fair price up to now anyways,

Did you install yourself, if not would you mind telling me what ball park the install cost?

The Pro-Jection works pretty well - I never had any problems with it.
I would think your typical back yard mechanic could easily do a throttle body type install, the multi port system requires an intake change though.
I installed the system myself.

Why not grab the 4.0L and all EFI system from a XJ and use that same as mopar kit at a fraction of price just a little more research and work

Mopar kit is just a OBD1 jeep set up put in a kit to make it simpler but given you only need to interface 5 wires to start an obd1 system and about 7 or 8 to make it run right its not that hard to do yourself

4.0L head flows a bit nicer and give a bit more grunt

Are you sure the Mopar kit is OBDI and not OBDII? I don't think OBDI handles sequential FI, does it?

 

[CJ]

~~~ Are you sure the Mopar kit is OBDI and not OBDII? I don't think OBDI handles sequential FI, does it?

Well, to answer my own question - Multi Port is used with OBDI.

 

[j0114]

Well i would grab the other engine but mine has 1500 miles i think on a brand new crate engine now, well prob closer to 2000 but not changing engines ,
ill fill out my profile tonight

 

[bmflyfish]

x2 for the holley Pro-jection. What part of Birmingham? I am in Hoover!

 

[j0114]

I live Downtown, I got a loft in the historic district on 1st Ave north,
I dont keep the Jeep there much, Its gated and got good security but still It stays inside,
I know hoover well, I used to live in Lake Crest for a bit, and have several friends who live there, well come to think of it Ive lived in several parts considered Hoover

 

[j0114]

Could anyone rate the systems we are discussing and give some pros and cons,
obviously price is part of the issue but I would like the whole picture

 

[CJ]

Could anyone rate the systems we are discussing and give some pros and cons,
obviously price is part of the issue but I would like the whole picture

Rate on what feature and what scale?

The Mopar unit is the most shofisticated because it is MPFI, the Holley is the most tunable because you can use a laptop to adjust the fuel map and the Howel is the simplest.

What is your rating criteria ?

I would suggest you download the manuals for all the units in discussion and see what you are in for...

 

[fzsk4p]

Hesco is the company that designed the MPI kit for AMC/Chrysler.

Hesco Inc. - High Performance Engine Service

Call and talk to Bennie. He (they) are super helpful and will be able to answer any and all questions you might have.

 

[BusaDave9]

is the Multi port produce alot more power or is it more efficient so to speak?

Throttle body fuel injection (like carburettors) will mix the gas and air before it even enters the intake manifold. Now the intake manifold is very important in keeping the fuel atomized. Gas may condense as it rounds curves in the manifold or touches cooler surfaces. An intake manifold made for high RPMs expects the air/fuel mixture to be moving fast so big runners are good. An intake manifold made for low RPMs has narrow runners to keep the air/fuel mixture flowing faster to keep the fuel suspended.

A multi-port injection is more complex and expensive because there are injectors for each cylinder. But now the intake manifold isn't nearly as important. It can be big and wide without having to worry about the fuel condensing. If the intake runners are long it doesn't matter because the fuel isn't added at the beginning of the intake. The fuel is injected as it enters the cylinders.

 

[CJ]

Forgot about FAST -->> http://www.fuelairspark.com/ezefi/

 

[Sasquach]

Could anyone rate the systems we are discussing and give some pros and cons,
obviously price is part of the issue but I would like the whole picture

I have the Mopar system and love it. For me it made the diference between keeping or selling the Jeep, yes it is a boat load of money and many people would not concider it a smart investment. If you feel your Jeep is worth spending the money on I say do it and never look back.
As pointed out though if you are a capable mechanic you can mostly reproduce the mopar system with junkyard parts from certain year 4.0 Jeeps.
No experience with the others to be able to rate them but can't say I have ever read a post about unhappy Howel owners so it may be a good choice as well.

 

[ThisGuyUKnow]

Why not grab the 4.0L and all EFI system from a XJ and use that same as mopar kit at a fraction of price just a little more research and work

Mopar kit is just a OBD1 jeep set up put in a kit to make it simpler but given you only need to interface 5 wires to start an obd1 system and about 7 or 8 to make it run right its not that hard to do yourself

4.0L head flows a bit nicer and give a bit more grunt

Well he doesn't have to do alot of research I have a junkyard MPFI and 4.0 head swap thread that is pretty detailed.

However I get the impression from his posts that the OP is not yet a skilled mechanic and the junkyard setup requires you to be able to read and understand electrical schematics. I may be assuming too much but sounds like it may be beyond the ops skill set.

Sasquatch has a really good thread on the MOPAR kit and 4.0 head as well.

 

[j0114]

I am not the best mechanic, and this may be a bit out of my range but on other builds, ive swapped engines, added on Fuel injection, A/C, Power steering etc on samurai's as well as doing my own lifts,
Its just my Jeep is alot more valuable than the zuki so I didnt mind to tear into it as much,
I also have did extensive mechanic jobs on my race quads rebuild engines etc,
But I do have a friend who is an awesome mechanic I would have on hand for this particular job to make sure it went smooth,

No I want the best for my jeep, I didnt put all of it into it but i got over 25k in receipts from the build so i dont want anything rigged etc,

I mis-understood ur post about the 4.0 fi kit,
I thought u meant get the entire 4.0 engine, I should have read your post
I have no problems getting the FI kit off an XJ or whatever is the best route and I got a guy who can always seem to find those kind of parts for you,
Ill research those post on the Junkyard kit,
The only thing is my Jeep runs great right now besides maybe being a little rich on the weber carb side but I know FI is the way to go,
Which ever way go It will be well documented
Thx for all the posts n help so far, after I research this more I may be Pm ing you with some detailed questions after I know exactly what I need etc,
thx again

 

[ThisGuyUKnow]

STANDARD SMP IDLE AIR CONTROL VALVE IAC AC151 | eBay

 

[Rescue Diver]

Sounds like the OP has a low mile stock AMC 258 i6 / 4.2l with a stock head that he doesn't plan to swap out. I'm thinking that the multi port injection manifold won't work on his head.

You're probably better off going with one of the throttel body setups for ease of installation. Any of them will perform just fine for you with your stock intake.