Egr.

[Cduke88]

Hello. I have a 84 CJ7 with AMC 258 i6 / 4.2l . I did the nutter and ran fine. Now when I floor it the motor spits and sputters sounds bad until I let off. I replaced fuel filter pump and all fuel lines. I thought that the egr might be bad so I completely removed it and now it idles horrible. I used to idle perfect. My accelerator pump is working fine. The carb is a Motorcraft 2100. I am completely lost here.

 

[Bent]

Kinda sounds like a vacuum leak at the egr port. Maybe pull the egr block off plate and reseal it. Make sure no exhaust is leaking between the two holes. The normal vacuum routing for the egr is to tee off from the ported vacuum line, run it down to a thermal vacuum switch and up to the egr valve. Make sure that is plugged/removed.

 

[Cduke88]

Do you have a diagram of the where the vacuum lines go?

 

[elwood blues]

 

[elwood blues]

If you ditched the CTO switch and EGR valve as well, this one is a little simpler

 

[Cduke88]

Thanks. If this don't work I guess I have to tear a new carb apart and check it.

 

[elwood blues]

Are you running an adapter plate on your intake manifold? If you are, check it for vacuum leaks. Spray carb cleaner around it while the engine is running.
When I was running a MC2100, I had an adapter plate that was warped and would not seal no matter how many gaskets I tried to use. Bought a better one from summit and it fixed it

 

[Cduke88]

Thanks. I tried that and no leaks. I am going to look at it again this afternoon. I only have a vacuum to the distributor and then the cto I am going to try to disconnect and plug the cto and see if that helps.

 

[Lumpy Grits]

Get some VERY soap water in a spray bottle. While the engine is running. Spray the heck out of the carb's base and all vacuum ports along with the intake manifold where is mates with the block.
My money in on another mc2100 leakage deal.

LG