Jeep 4.0 EFI on 2F

[IPOR]

Has anyone ever fitted a 2F with the MPI from a Jeep inline 6?

I know MPI is not the flavor of the week due to the additional work required to fit the injectors over TBI, but wouldn't the jeep motor have similar fuel requirements? It seems like programming the chip properly is the biggest problem with the chevy TBI swap, I wonder if the jeep would work any better without all the monkeying around.

I'd like to hear from anyone who has ideas or concerns regarding this swap. Please, no recommendations to just use chevy TBI, that's not the point of this discussion... and besides, I already have the jeep. No, I haven't lost my mind, I needed the rear half for a jig to assemble a bumper on (friend has an XJ and wanted us to build him one) so I bought the whole thing (running) for $200.

As cheap and plentiful as Jeeps are I think this exercise might be useful to someone. Anyone tried this before?

Lance
www.ironpigoffroad.com

 

[IPOR]

I'll get us started here:

The fuel rail will need to be modified. The manifold layout (where intake and exhaust ports are located) is different than the 2F, so no simple manifold adapter to allow use of the jeep intake on the cruiser motor. I don't think this is a major problem, seems pretty simple to section the fuel rail and TIG back together with injectors in proper location.

There would appear to be two ways to fit the actual injectors into the intake manifold:

1. TIG a bung into each intake runner on an OEM 2F intake. Seems like even with TIG this is likely to distort the manifold and require milling.

2. Fabricate a spacer to fit between intake and head that has injector bungs in it already. The spacer would need to be at least 1.5" thick, which could lead to clearance issues with other underhood components like the brake booster. Also, it may present a problem with how to bolt everything back together securely without in/ex leaks.

Suggestions? Comments?

Lance
www.ironpigoffroad.com

 

[IPOR]

What about injector angle? On the Jeep motor the injectors are angled at about 45* or so towards the intake valve. I think 3fe's are also this way. How critical is this angle?

I know I've seen homebrew EFI setups that simply had the injectors at 90* to the runners. The one I'm thinking of was one Tup Purcel had put together years ago on an F engine using chevy parts. It ran fine other than some quirky issues related to chip programming.

Mike? Anyone with good homebrew EFI know how out there?

Lance
www.ironpigoffroad.com

 

[cabron]

A J$%P motor in a Cruiser, oh that's bad karma. Seriously, the reliability of the J%^P motor would be something that would steer me away from putting it in my rig. Just my two pesos.

 

[zebrabeefj40]

I think Clifford was working on a port injection manifold for Cruiser I6 motors at one point several years ago. There was much discussion on Pirate about it as well. I think a couple other folks were doing something similar by welding injector bungs into the stock manifold. I think the information you want will be found on Pirate or a dyi-efi board. I think there are a couple of them around. Maybe search for some of the various aftermarket computer systems like MegaSquirt for their specific boards as well.

Properly TIG welded, there should be little to no distortion of the manifold after welding injector bungs in. Most bungs are pretty thin machined parts. Using enough heat to warp the intake would likely destroy the bungs IMHO. Machining the intake is a part of the equation regardless if you want to get the bungs into it at a consistant angle. Just blowing a hole in with a hand drill isn't the right way IMHO! The holes also need to work with a modified/new fuel rail. In my eyes, punching the holes in with a mill means they should be consistant enough to match up with a custom machined fuel rail. A rail which ought to be better than just a few pieces of pipe welded together. The whole system needs to support 40-60 PSI of fuel pressure too. Means upgraded lines throughout.

One of the other issues you'll run into related to EFI is timing control. One of the reasons TBI works pretty well as a conversion is because it does not have to control the distributor to work well. It amounts to an electronically controled fuel metering device; a very precise carb if you will. If the Jeep system has timing controls built in then you'll have to work something out for that. A converted HEI might get around it. Bottom of the HEI machined to match a Cruiser motor with the top converted to work with tht Jeep electronics. Talk about a bastard child! That leads to the next concern I have...

In the end, other than the philosophical differences (Jeep parts on a Cruiser) it might work ok. Having had an aftermarket EFI converted truck in the past one of the biggest issues I found was support of the system after it was installed. If you're planning on selling such a system through IPOR then you NEED to document it VERY WELL. Replacement part and complete troubleshooting info are just as important as having it work when it leaves the shop. The parts need to be available after IPOR or whoever has gone out of business or stops supporting the system. Finding someone to fix this sort of deal is very difficult. Most mechanics wouldn't touch it with someone else's 10' pole so it has to be owner serviceable.

I'm sure there is far more to it but that's what can think of off the top of my head. Nothing to do but to do it and see what you REALLY need to do to make it work!

HTH,
Nick

 

[Mr. Toad]

Anyone with good homebrew EFI know how out there?
It seems like programming the chip properly is the biggest problem with the chevy TBI swap.
Please, no recommendations to just use chevy TBI, that's not the point of this discussion...
www.ironpigoffroad.com

I believe I'm following your rules of engagement here...

Use a Megasquirt computer with a Chev TBI Unit or with whatever rail design you come up with. It leaves the Cruiser engine's electrical functions alone and only administers fuel: Basically it uses engine and air temp, throttle position, RPM, vacuum, and oxygen sensor data to administer the right dose of fuel. You don't have to worry about programming GM's crappy computer EPROM either. Of course, if you want the Megasquirt to do more, it can. It's very simple, and it works.

Personally, I think anyone who decides to convert an ancient Cruiser to FI without Megasquirt should c'mon in to the 21st century. It's nice here.

Edit: After reading ZebrabeeFJ40's comments more thoroughly, I should clarify my comments. I'd recommend Megasquirt for someone who wants something that works, but who also knows how and why it works. In fact, this is the only person I'd recommend any EFI conversion to. This person would be self-sufficient as far as support goes. I'm not sure that Megasquirt or any other aftermarket EFI is a good idea as a vendor-offerred and supported product package, unless the vendor is dedicated exclusively to that product.

 

[projektdotnet]

I know MPI is not the flavor of the week due to the additional work required to fit the injectors over TBI,

ih8TBI...had (between me and some friends) about 4 or 5 cars with TBI and when those things stop squirtin right it is PITA!! I would much perfer MPI but now off a heep...i mean...cmon...go with Chevoda or Toyord...buy Jeyota...thats just...WRONG!!!

 

[fj40charles]

A J$%P motor in a Cruiser, oh that's bad karma. Seriously, the reliability of the J%^P motor would be something that would steer me away from putting it in my rig. Just my two pesos.

What makes you think a 4.0 liter fuel injected motor is not reliable compared to a 2F?" 2F motors are good, but they're no more reliable than any well maintained SBC or 4.0 AMC motor.

 

[IPOR]

LOL! Yeah, I thought the genetics of the swap would find malice here on MUD. Let me put you all at ease: I'm not planning on offering any such product from IPOR. Maybe a MPI or TBI kit based on all new parts (chevy), but no DIY kits made from used jeep parts.

This is just about a guy who doesn't know when to quit, that happens to have a fuel injected motor of similar displacement that will be heading to the scrap yard if I can't find a better use for it.

TIG welding the manifold I can do in house, no problems there or with the fuel rail. I still wouldn't be comfortable without milling the manifold afterwards - true TIG is very controlled heat, but it's not worth the $100 it costs to mill it just to take it all apart again due to a manifold leak. The dizzy seems to be the biggest issue, that and the possibility that the Jeep differs significantly enough to require reprogramming... if it's even possible with that ECU.

This is not a project for my DD (95FZJ80), nor my boulevard queen (TBI350), nor my trail beater (carb'd cruiser buggy soon to be replaced with custom built FZJ50 (long wheelbase 40 on 80 chasis & drivertrain)). It's just a solution to reliable starts and predictable performance for a farm truck a few friends of mine and I built for my dad some years ago. It's in need of a carb rebuild, and I just can't do another carb'd truck.

Thanks for the responses, keep 'em coming.

Lance
www.ironpigoffroad.com

 

[mattg]

Since you can handle the manifold mods, MPI would be a great way to go. Megasquirt seems like the obvious choice. Any setup is going to require some PCM programming/tuning, so you're no worse off with Megasquirt vs. Jeep/GM/etc.

For a farm truck, avoiding computer controlled ignition seems like the best bet for simplicity. That way you avoid cam/crank sensors. Just use a Megasquirt and 80-87 Toyota electronic ignition. Good startups, more reliable, relatively simple.

Just my $.02, as I'm certainly no expert on this.

 

[FJ40Jim]

Lance, you are right that the jeep is a 4.0L inline six, like the 3FE, but the similarity ends there. There is nothing to make the jeep stuff useful to the cruiser engine. The code is very different because the 4.0 is a high-revving modern roller-cammed engine. The 2F is.. well....not. The injector rail is useless because manifold runner spacing is different. The CKP sensor is in the AMC dizzy, which doesn't drop into the 2F.

I too have thought about it, but rejected for the above reasons. IMO a person is better off starting w/ 3FE hardware and a megasquirt. If 3FE is hard to come by, then use a TB off some common GMC or Bosch application, and standard bosch injectors on a late model 2F intake manifold. mill & weld bungs. Fab a fuel rail like on an old 280Z or 4ME supra, w/ short stubs of fuel line to allow for imperfect fits. Use a Toy big cap dissy w/ timing locked out as timing ref signal.

That's how I would do it, if I had time to do it.

 

[cruiserhead]

Jim give me the specifics and I`ll make one for you.In other words you engineer it and I`ll build 2.
Hope to see you at CMCC `06,
David

 

[FJ40Jim]

Jim give me the specifics and I`ll make one for you.In other words you engineer it and I`ll build 2.
Hope to see you at CMCC `06,
David

David, you are a bad man, trying to tempt me.;p

We need a common TB w/ a simple TPS, something w/ similar HP and displacement. 4.0L Ford ranger/aerostar/exploder maybe?
Which would require a simple adapter to go from a square 4-bolt patter to the rectangle 4bolt on the 2F intake. It would be nice to get it lined up so that the stock throttle linkage could be reused after a ball stud is welded to the throttle arm. Then another very simple adapter from the round TB to the bottom of the round 2F aircleaner neck.

And 6 injectors like this.
Note the 8mm (5/16") flex hoses on the injectors and common electrical connector. Fuel flow for +160HP @ 32PSI. More HP available at higher pressure.