Fuel delivery for 86 CJ-7

catfishblues

catfishblues

Well-Known Member
Joined
Jul 26, 2005
Location
Pfafftown, NC
My buddy has an 86 CJ with the 4.2. It's already been swapped over to a Weber, but still has about half a mile of vacuum tube under the hood that needs to be cleaned up. I know they can be fairly reliable, but I've always hated every one I've ever owned or installed. It started acting up last weekend, so I think it's time to start considering alternatives. He's not particularly comfortable with dealing with temperamental carbs, and can't afford for it to leave him stranded halfway home. Is a 2100 a better option? Is there an affordable, simple FI swap besides salvaged TBI stuff?
 
Rip all that crap out and buy a Holley tbi system. Been there,done that.
Howell makes a good system also but their customer service sucks ass.
Trust me...
 
There are two Weber's that are typically spec'd for the 4.2, the 32/36 or the 38/38. If he got the 32/36 that's probably part of the problem, as the 38 is better suited for that engine.

If you search, there are just as many people saying the Weber 38 is better than the MC2100/2150 as there are saying the MC2100/2150 is better than the Weber 38.

If he want's to stick with a carb, either is fine. I chose the MC2150 due to parts availability from the local parts stores (MC's are on everything).

I would do what @a_kelley and @sammi_davis said first though and source a junkyard early 4.0 EFI system...

Edit: also make sure he does the Nutter bypass as well.
 
There's a 2100/2150, for sale on here, even if it is attached to a 304 intake. When i had the 6 cylinder, the MC had a few flooding problems, but that was under hard bounce on a steep hill. My 304 with MC, is about as perfect as any carburetor Can be! But EFI is Sweet!
 
It's a 1.21 Venturi to much bigness.
Start by locating the computer behind the glove box. Remove everything that attaches to it. Get a hei dist less than 100 on eBay. Keep your sensor wires (oil pressure, water temp) but everything else can go. I've got a mc2100 and like it. The 4.0 head swap seems like a lot of work to convert over, if I was serious about wanting FI I'd probably find a early 90s wrecked Cherokee and do the whole swap.
Mc2100/hei is the cheapest, quickest and "reliable" solution. IMO.
Find a 1.08 Venturi, Mr Gasket 1937 adapter and fab up a simple throttle cable adapter. You'll have one vacuum line to dist. A couple wires to dist. And one to electric choke. Everything else can go and get plugged.


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josh m said:
fab up a simple throttle cable adapter.
Click to expand...
Here's my fabricobbled throttle adapter. Been working fine!

IMG_2593.JPG
 
My first cj was nuttered with a 2100, it ran great. Current cj has a 4.0 with the factory efi, it runs even better. I would highly recommend either setup.
 
I run a GM 6.0- but I literally wish I still had my 4.2 with big bore weber
 
catfishblues said:
Is there an affordable, simple FI swap besides salvaged TBI stuff?
Click to expand...

:flipoff2:
I know a guy... that's done a couple of them and even has a Moates2 burner for very quick turn around between tunes (after upgrading to EEPROMS from those neanderthal UV erasable EPROMS)
IMHO, it could be done for less than $200 with the right supplier

Exhibit A
Exhibit B
 
Last edited:
Caver Dave said:
:flipoff2:
I know a guy... that's done a couple of them and even has a Moates2 burner for very quick turn around between tunes (after upgrading to EEPROMS from those neanderthal UV erasable EPROMS)
IMHO, it could be done for less than $200 with the right supplier

Exhibit A
Exhibit B
Click to expand...


Speaking of.........I guess I should have reminded you about the diagrams.:huggy:
 
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