mumbling n grumbling at a stop light

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duster wonder

duster wonder

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hello all, ben awhile. enjoyin my new 360, ben puttin quite a few miles on er. 360 bored over kb slugs 9.5 somethin ratio comp cam 480 lift? dual plain intake, eddy carb just rebuilt, long tube headers, stock distributor, msd wires. msd coil. 2200 stall convertor

but, doesnt like sitting at a stop light. after a half hour or so of drivin around (to get hot) she mumbles at a stop light, almost like its forgeting to fire a cylinder. the more stop lights i sit at the worse it gets, occasionaly it will just shut off. 750 rpm, 1000 when not in gear. if i lightly step on the go button, stops grumblin. whats goin on? messed around with timing and seems not help wherever i put it (at about 34 right now) runs like a champ otherwise.

carb need adjusting? or time to get a new distributor? (recently rebuilt) timing being goofy? (all in specs)

dad said to try premium gas, ill see what that does later. most likely something really simple, but i like hearing what you guys have to say
 
I think you need more initial timing. prob in the 15-18* range. that involves recurving your dizzy. if you search on here there are several threads on it. is it running excessivly rich? might be loading up.
 
wouldnt there be a tint of smoke if too rich? spose i can try adjusting the carb screws, bein the first time we did that timing was way off.

up next is a shift kit, takes a whole 3 seconds to shift into 2nd
 
before you even take the air cleaner off that carb you need to get the timing squared away. that is the FIRST step to tuning. the timing events directly effect the air/fuel. find out what your initial timing is with the car idling in gear (parking brake set). then find out what your timing is at in park or neutral at about 3500 rpm. have a buddy sit in the car and get your timing light out. have him/her very gradually bring the rpm up until you see the timing stop advancing. my guess is that you have very little initial timing and it is coming in way too late. I am no pro here but i have got alot of help with this exact topic from members here and i have been reading a ton. what i think you need is about 15-18* of initial timing and a total of about 34-36* BTDC (before top dead center) and it should be all in by about 2800-3000 rpm. this is more then likely gonna require a recurve on your dizzy.
 
What kinda carburetor gasket do you have under the carburetor? You should have a really thick one. It helps insulate the carburetor and keep the fuel from getting too hot and possibly boiling. If you don't have one, you might even get one like this with a shield on it.

http://www.summitracing.com/parts/mrg-3710/overview/

You would put the thick gasket on the manifold and that heat shield ^^^^^ on top of the thick gasket. Although as others have said, you will want to double check the tuning, that heat shield cannot hurt. I wouldn't put one together without some form of heat protection for the carburetor.
 
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