My carb hates me.

Collin the Hen · #1 (**permalink**) 08-05-2008, 08:45 PM

I have an '84 CJ7 with a 4.2. The previous owner put the motorcraft 2100 in and I absolutely hate it. I can't get it to run right. At first, it wouldn't idle, so I took it apart and fixed that with the help of new spark plugs. Then, there was a mysterious leak that sounded like a tv. After I fixed that, it would idle at around 1100 or so and diesel. I then fixed that because the butterfly valves were off just a hair. Now, after it's all put back together, it'll idle idle down to about 400 if I wanted it to, BUT, when it hits 1200 or so, it coughs and sneezes until it stalls out!

I hate this stupid carb! Can anyone point me in the right direction?!?! It's supposed to be the ideal carb (1.08, 48f jets), but I'm just loosing sleep over this dumb thing.
By the way, this is a weird 2100. It had a lever on the front by the accelerator pump that goes over the air horn, and it has a big 3 on the bottom. I think it's a lemon carb.

Collin the Hen · #2 (**permalink**) 08-06-2008, 03:33 PM

Well, since no one is replying, I'm just going to start saving for a Weber 34/34 kit. I hear that they're tricky to tune, but I figure they can't be nearly as bad as this worn out 2100. I remember looking at the shaft, and it is worn pretty bad, so other components may be tired as well.
As you can see, I'm scraping the bottom of the barrel here.

Bounty__Hunter · #3 (**permalink**) 08-06-2008, 04:46 PM

Why not buck up for a reman 2100 that you know will be good?

I don't know much about carbs, but it could be just worn out, wrong jets, vacuum leak, etc.

Collin the Hen · #4 (**permalink**) 08-06-2008, 06:02 PM

Thanks for the reply. I'll take that into consideration. I'll match up some prices and see what's more feasible. It would be nice to just get a nice 2100 so I could just bolt it right in.

Bounty__Hunter · #5 (**permalink**) 08-06-2008, 11:37 PM

I've heard a lot more positives about the Motorcraft carb, including ease of tuning and operation at angles.

lah2420 · #6 (**permalink**) 08-07-2008, 06:07 PM

If the shafts are worn out it will suck air around them too. I love mine. It runs and idles great. I just have to remember to keep my foot out of it. It will suck the gas if I have to get on it. Of course, any carb will do that.

Collin the Hen · #7 (**permalink**) 08-08-2008, 11:13 PM

So I figured it out. I figured my A/F screws were in the right spot from my previous setup, it was out 2 1/2 turns. I thought I might as well try turning it in some. I turned it 2 full turns from being set, and low and behold it idled and revved up like nothing! I was in a hurry, so I didn't plug my vac. gage in for long, just enough to where it was steady at 19 Hg.
One thing I noticed is that when I'm at about 1200 rpms or so and I let off the gas, it grumbles a little bit. It sounds kinda cool, but I'm probably running too rich. I'll use my vac. gage more tomorrow and get it right. I also "checked" my gas mileage, and a very rough estimate is at least 15, but I'm thinking it's a little more.
Sorry for my grumbling, but I was absolutely stumped.
I also checked out some Webers. I'm glad I didn't buy one, I guess they can be a bear to tune.