[petey156]

I have read that some people do the nutter by-pass when they swap for the MC2100. Some people do not mention it. Is it needed? what does it actually do?
I have a 77 cj-5 258 I6.
thanks
Preston

[7DJEEP]

I have done both, in fact that is all I have done to my stock 1984 CJ7. I ran the new carb for almost a year. I bought my jeep cheap because of the stock Carter Carb being a piece of crap and the previous owner gave up I think. It made a huge difference and have not had any problems with it, I would recomend an electric choke, it starts and runs good in any temp. I did the nutter bypass a month or two ago, I think it runs a lot better and it didn't cost anything. I think the ignition still lacks so I plan to do a Chevy distributer and coil upgrade in the future.

-B

[ScottJ]

I had to nutter my 1985 to get it to run right after the Weber swap.

I'd fiddled and fiddled with the Weber and the Jeep would still stumble and fall on its face every now & then.

I finally figured out it was the computer screwing with the timing.

I still think I have some work to do to get the Weber fully sorted and sometimes I get a rough idle (might be fouled plugs or I might need a TFI mod). I really need to drive it more to get things sorted but I only have a bikini top and the weather hasn't cooperated lately.

[Geer_hed]

The short answer to your question is that after the carburetor is swapped, the only thing the computer has dominion over is spark advance. The nutter bypass removes timing from computer control as well.

BUT - as ScottJ pointed out above - why would anyone have a non-feedback carb running in a system designed for sensor feedback via EECU, and leave the EECU installed and powered? You shouldn't. If you do, it's just asking for more goofy issues to troubleshoot. The grander purpose of the MC21xx mod is a superior idle over the Carter, but if that's the case, why would anyone leave the EECU with control over the spark advance where it can skew timing and foul your idle all to hell?

So this is not such a short answer But realistically, the 2100 literally can run with the EECU setup, it's just not the best idea. Two birds one stone... do em both...