90 WRANGLER.... JEEP IS LEAVING A BLACK SOOT SPOT ON THE CARPORT EVERY TIME IT IS CRANKED, WHEN ITS CRANKS AND THE FAST IDEL KICKS IN IT BLOWS THAT BLACK CRAP ALL OVER THE FLOOR, WHAT CAN I LOOK FOR....POSSIBLE CAT..STOPPED UP...RUNS FINE HAD TO PUT A NEW CARB ON IT, BUT ITS NOT FLOODING.

Sorry to let you into the facts...but it is SUPPOSED to do that! When cold the carb or fuel injection gives a RICH mixture so the engine WILL START! A cold engine will NOT start on the same mixture it will run on.
I have black spots on my garage floor too.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

well now, i learn something new everyday...thanks for the info jim

By the way Coach... Do you still have the factory carb on there? My experiences with the motorcraft carb that everyone touts have showed me that the PUMP in it prolly uses more fuel at each pedal push than the factory carb does.. Which in turn causes a bit more soot.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

yeah got the new one on, runs great, just that soot thing, checked my exhaust out, pin holes all in it, think i will have it replaced lot of age on it any way

OK JIM NOW IM READY TO PULL MY HAIR OUT, THE NEW CARB WORKED FINE FOR BOUT A WEEK I GUESS, AND NOW IT HAS STARTED THE SAME CRAP, RUN'S FINE AT HW-SPEED COME TO A RED LIGHT AND IT DIE'S IT WILL NOT IDEL I HAVE UNPLUGGED ALL VAC-LINES, TO MAKE SURE IT WAS NOT LEAKING PAST THE CARB IN A AREA THAT I COULD NOT SEE,,,DID THE SAME...IM TO THE POINT WHERE IM READY TO SELL IT...OR PUT A CHEVY ENGINE IN IT, IF I KEEP IT, I HAVE NEVER SEEN ANYTHING LIKE IT...WHAT ELSE IS THEIR TO CHECK..... <img src="/forums/images/graemlins/confused.gif" alt="" />

I think it is becoming obvious that the carb is not the problem.
Does it at least attempt to idle? Do you have the idle set too low? Do you have the idle screws set too lean?
Can you adjust the fast idle screw till it WILL idle? If so do that and then open the idle screws and see if BOTH of them increase the idle speed.. then lower the fast idle screw and increase the idle screws again... then lower the fast idle again and adjust the idle screws again.. do this till you get to a point where it is too rich and then back off 1/2 turn and see if that was the problem.
Of course you could easily have a worn dist or other part that would make it not idle.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

OK JIM TRIED ALL THAT AND NO LUCK...WHAT GETS ME IS THIS JEEP RAN PERFECT, BEFORE THE PISTON CAME APART..I PUT A NEW ENGINE IN NOT A RE-MAN...HAD THE HEAD WORKED....AND IT HAS NOT RAN THE SAME SENCE....AND FOR IT TO RUN PERFECT WHEN U GIVE IT THE GAS..NO SKIPS TRAVELING....JUST CANT IDEL FOR NOTHING.....STARTING TO WONDER IF I NEED TO PULL THE HEAD OFF AND HAVE IT RE-CHECKED

Coach have you put the propane test to the intake gaskets?
Have you set the choke to a rich position and saw wheather or not that helped it to idle?
If it has time and fuel it should run. Unless it is getting too much AIR from a leak.
Also you just might have picked up a little dirt and clogged the idle jets.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

jim i tried the choke test when i try to close the choke it starts to flood,and the propane test i have never heard of..how do i do it?...this is the new carb i just installed, it should be clean