Post your efi/4.0 swap conversion questions here

[tougeagle]

If you have any questions about 4.0 head swaps, efi or anything of that nature, post them here for others to see as well, perhaps some of them have the same question

[ericarmstrong]

Do you know where to find a full PCM to component schematic?? I have a hanes manual that is weak at best and  the 93-95 jeep Factoory service manual  I have bust things up (as I'm sure you know).

[tougeagle]

Do you know where to find a full PCM to component schematic?? I have a hanes manual that is weak at best and  the 93-95 jeep Factoory service manual  I have bust things up (as I'm sure you know).

the FSM is the best way to go, that's what I used to wire everything in. Are you talking about a pinout diagram, that shows where the 60 different pins lead to in the harness? Also, some of the colors may be off, but not by much, however it will work as long as you make sure whatever wire in question is in the same location as shown.

[ericarmstrong]

I'm sure I'll be fine with this FSM.. I just work better with a full schematic, much like the old ones  AMC and GM used to do. It seems to save a ton of random page flipping. BTW, I like this "Post your efi/4.0 swap conversion questions here" idea, a lot of the same info is floating between many different threads. Can this be stickied under "altered eagles" ,"engine", or  somewhere. I'm afraid this will go dormant, get pushed down the page, and defeat the purpose.

[tougeagle]

I'm sure I'll be fine with this FSM.. I just work better with a full schematic, much like the old ones  AMC and GM used to do. It seems to save a ton of random page flipping. BTW, I like this "Post your efi/4.0 swap conversion questions here" idea, a lot of the same info is floating between many different threads. Can this be stickied under "altered eagles" ,"engine", or  somewhere. I'm afraid this will go dormant, get pushed down the page, and defeat the purpose.

I know what you mean, full schematics tend to be a bit easier. If you have the entire FSM, I can probably just send you a copy of mine on the computer, might make things easier. I don't usually give it out because technically it's not mine, but you already have one, so it's all good if you need to use it.  I'll definitely see if I can get it stickied... thinking either here or altered eagles.. .I need to see if IE can sticky my conversion writeup to altered eagles and the 'pedia too.

[shanebo]

what year grand cherokee did you get that manifold off of

[tougeagle]

I don't remember what year but it will work for any 4.0 head 91 and up. Casting 7120 is the head it came from, I remember that much.That run went from 91-95. 96 was the same but without the port for the sending unit for temp gauge.

[eagle503]

How much $ did this take? I want to go cheap. the mc2100 is only $250 how much is a used efi setup? I just want to get rid of the carter bbd - sometimes it starts rite up and sometimes it just wont.
Thanks!

[ericarmstrong]

Tougeagle's writeup gives the best breakdown regarding parts and $ I've seen yet.  http://forums.amceaglenest.com/index.php?topic=32540.30

[tougeagle]

I'll add... those prices are what I paid and/or what you can expect to pay. You may find them much, much cheaper (craigslist and jeep forums are your friend) or everything on that list may be twice as much.... JUST the EFI itself, without head and cam, and including the transmission, was around....600 iirc.....which isn't that much compared to what you get out of it. The efi stuff will bolt up to the 4.2 head,but you'll have to ditch the entire pulse air system and crimp the tubes, and you will have to update all fuel line to EFI pressure rated hose.. not to mention the wiring n stuff. It's not that biga deal though

[shanebo]

Ive been meaning to ask ya.. where did you mount the new fuel pump?

Thanks
shane

[tougeagle]

Ive been meaning to ask ya.. where did you mount the new fuel pump?

Thanks
shane

Exact same location as the old one, on the spare tire well bulge (on the outside) several inches above the gas tank.

Also, you may read or have been told that you need a smaller pump to help push gas to it.... that's not true if you do your research and buy a good pump. That pump had no problem pulling gas through dry lines and pressurizing the fuel rail after I installed it. It took three clicks to "run" position and I had proper fuel pressure.

[shanebo]

OK Man, this is going to make me sound real supid ...but here it goes...I really have very little understanding of the fuel system....So there is a pump in the back by the tank...is there going to be a secondary pump up front where the old cam-driven pump was or is that deleted with a more powerful rear pump.

[tougeagle]

OK Man, this is going to make me sound real supid ...but here it goes...I really have very little understanding of the fuel system....So there is a pump in the back by the tank...is there going to be a secondary pump up front where the old cam-driven pump was or is that deleted with a more powerful rear pump.

The fuel pump hole will be deleted and gasketed with a small block chebby block off plate, and your 4.0 ignition coil, which just happens to bolt right up. EFI requires much higher fuel pressure and flow, your pump will need to push 70 or so psi at least, and 40 gph. I like having room to improve in the future, so I have an 87 gph pump... You would be using a return fuel rail, and hooking the return hose from it to the steel return line that used to be hooked to the fuel filter in line to your carb. You will not need any kind of other pump to assist as long as you go with a decent pump. A good pump will have no problem priming a completely dry fuel system with three KOEO (key on engine off) cycles. Mine was 220 from summit, I ditched the noisy bosch. The one from summit is also a Walbro. It's in the Edelbrock performer efi kits.

Your fuel hose will have to be efi rated, no ifs ands or buts.  Regular fuel hose is J30R7, EFI is J30R9.

[shanebo]

Thanks man!!! Thats just what I needed to know