ideas? suggestions? mc 2100 swappers need help!

KG4PAM · 05-08-2002, 10:49 AM

i replaced the carb(mc2100)on my jeep with a factory rebuilt one. it ran good for a week even, about 350 miles, then started running rough. whats weird though, it is only rough sometimes. i had been driving it around all day, with no problems. i stopped at the top of a hill in the campgroung where my dad and i work. pulled down to the camper(200 feet) and was terribly rough idleing. since then it has been so unpredictable as to force me to stop driving it. sometimes its good, often not. also it is a pain in the morning to crank if it has sat all night. i checked vac. leaks with propane, no problems there. took off the EGR and cleaned it out 'cuz i thought it could be dumping too much exhaust in the intake. that didnt help. the one thing that did seem to help was a new rotor, dist. cap, plugs, and plug wires. DO YOU KNOW WHATS WRONG????? please give me some suggestions!!
p.s. i can pull off the vac. advance hose and nothing happens to the idle...

MR.CJ-7 · 05-10-2002, 06:50 AM

Had the same problem with mine about a week ago. Turned out to be a bad power valve. Did they do a complete rebuild(unlikely) or just fix what was bad(more likely)? If it was the second option pull it off take it to a reputable rebuilder(or do it yourself if you can). Two years ago when mine was rebuilt it just needed a gasket kit and a float and was about $20 for the kit. This time it needed a full kit with all components and was about $40 for the kit.

Just my $.02 worth

Good luck to you

jeepdaddy2000 · 05-10-2002, 09:42 PM

The power valve is in that little bump under the front of the float bowl. Take the four screws out and drop the cover. If there is fuel in the cover, the valve is bad.All it takes is one little backfire to rupture the diaphragm causing it to leak. If the valve is bad, simply unscrew it and replace with a new one(take your list# or carb# to your local parts house, they can sell you a new one).Be sure to check the cover for warpage. If it is warped, place a piece of light sandpaper on a flat surfice and "mill" it flat. Don't forget to readjust your idle mixture when your done.