mc 2100 conversion problems -

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post #1 of 5 Old 04-14-2005, 07:46 PM Thread Starter
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Question mc 2100 conversion problems

I did the mc2100 conversion from the carter and have a bad vac leak in the gaskets. the adpater seems OK but I think the problem is in the gasket between the carb and adapter. I spray starter fluid around the gaskets and get a definite rise in rpm. I tried to seal with permatex (2b) and problem is still there. The effect of this seems to screw up my acceleration. From a stop, as I give it some gas, it revs up, I let out the clutch and it just chugs right down to almost a stall if I don't floor it or push the clutch back in.
As I gradually/slowly increase speed I can't give it too much gas or she stalls or hesitates (I checked timing and vaccuum and dist. advance is on a ported vac tube. I also changed fule filters and pump.). Once I get going, about 30 or so, I can get it to accel if I don't step on it too much. If I do the carb starts to spit until it catches again.
I would like to try and new gasket between the adapter and carb but don't know which ones to try. Theone I havenow came with the kit and is a paper gasket about 1/4" thick. I got a NAPA part number of 2-7694 for something different to try but NAPA says they don't carry that anymore.
Dont know if this is related or not but am having a hell of time trying to warm her up. It starts up right away, revs up, and then keeps trying to die. I'm feathering it from that point on trying to let it warm up. It takes about 10 minutes to warm up till it idles nice. I even changed the coil on the electric choke but noticed the one off the carter was a motorcraft also (after I wasted my time of course), so didn't seem to help.
what gasket? and what gives witht he idle?

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post #2 of 5 Old 04-14-2005, 10:50 PM
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You are fighting a manifold leak. The engine won''t start or run right untill it is fixed. The baseplate's come in two different styles, so you need to remove the carb and check to see if the gasket completly covers the baseplate. If so, then you need to check to see that the gasket covers the manifold, and there isn't any damage to the mating surfaces. Some Motorcraft carbs come with a port in the rear for the EGR valve. If yours has it, is it connected or plugged?
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post #3 of 5 Old 04-15-2005, 05:33 AM Thread Starter
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I am using the big port at the rear of he carb for PCV. My EGR is connected through the thermal switch.
The gasket looks like it covers the base of the carb well enough. I had everything off and stacked upside and if there is any place that is suspect, it is the thick paper gasket between the carb and adapter. I get lots of blank stares and dead air on the phone from the auto parts stores around here when I ask for something to replace it....don't know why. Any recommendations on a better gasket?
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post #4 of 5 Old 04-15-2005, 09:42 AM
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I had the same problem with my Weber. I bought a new set of those paper gaskets from Weber and coated them with this copper spray sealant this time. It comes in a spray can and is made by Permatex I think. I found it in the sealant section of the parts store. Since then my adapter plates have stayed completely dry and it no londer misfires at low RPMs if I'm not flooring it.

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'95 XJ - Donated drive train to the YJ, Parted out the rest

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post #5 of 5 Old 04-15-2005, 07:29 PM Thread Starter
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I picked up 2 gaskets at advance auto today. they had one for the 2100 and one for the 2150. i compared them to the one i already had and the 2100 was fine. the 2150 was a little off so i didn't use it.
I cleaned off the crap that the permatex left and tried the new gasket. same vacuum leak...same areas. next step, i guess, is to try to make a gasket. I think there's a material that i can get to cut to shape.
If that doesn't work I think I'll try to assemble on the bench and seal the outside edges as well and hope for the best.
still hoping someone has a magic number for me for a different gasket to try.
I think the spray adhesive may be a good idea too. Thanks, tshark....
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