MC2100 questions

muddave · #1 (**permalink**) 09-30-2005, 10:42 AM

I installed this carb that I bought used on Ebay. I was told that this was a re manufactured carb and was only ran for a couple of weeks and then stored for 2 years. I did not replace the power valve like the instructions said--everywhere I went (Autozone, Napa etc.) did not know anything about a 2-stage power valve for this carb. I also did not rebuild it since it was re manufactured.
My problem--I have been having several problems since the installation-mainly- hard starting and not wanting stay running when put in drive when cold but it runs fine once it's warm. When I start it cold, it goes to fast idle and runs fine until I put it in gear then it just wants to die. If I leave it in park in idle it will run fine. If I want to make it run I can gun the motor and throw it in drive and sometimes this works. I thought this was a vacuum issue so I went over the entire carb with carb cleaner spray and cannot detect any leaks. I have also replaced the auto choke with a manual one.
I have decided to rebuild the carb and replace the power valve if someone can help me with a part #, Please! Or if any one has any other ideas of what my problem might be please help. Any suggestions are greatly appreciated!!
This carb is on a 1980 CJ7 258 6cyl. Auto. The carb has the 108 Venturas.
Thanks,
David

GaryMB · #2 (**permalink**) 09-30-2005, 08:17 PM

Please refrain from swearing...N*pa and A*tozone are your first problem

There are so many reasons not to shop at places like that i don't know where to begin. Try to find an independant auto supply store in your area; they are almost always your best bet. As for the cold idle problem, it sounds like your choke is not set right. Before tearing appart your carb, I would check the carb and choke adjustments. The choke could be making it run too rich or lean. By the way, what type of choke is it?

muddave · #3 (**permalink**) 10-01-2005, 09:25 AM

Sorry, I forgot to put it in my post that I have already switched to a manual choke.

Also, can anyone explain to me how the fast idle cam works? What causes it to engage/disengage?
Thanks again for any help!
David

SenorCole86 · #4 (**permalink**) 10-02-2005, 12:02 PM

Explaining the actual linkage I think would be extremely difficult to do in words, but I think I can explain the process. When you're about to start it up, push the skinny pedal to the floor and while it is down, close the choke. This sets the choke plate closed and the fast idle linkage keeps the idle up high so your engine can warm up. When you think your engine is warm enough, open the choke. Once you give it enough gas to disengage the fast idle stuff, it will, letting the idle screw take over idle rpm. I hope this helps. I think the best to way to understand how all the linkage works, is to just sit there with the carb in your lap or even on the manifold (with the Jeep off) and mess with the choke and throttle until you figure it all out. If you follow this^ process from within the engine bay, it should become pretty apparent how it works. Again, I hope this helps, good luck!