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Tim's Auto Repair
Tim's Auto Repair, Mechanic
Category: Car
Satisfied Customers: 16026
Experience:  Have owned a repair shop for 25 yrs.
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rebuilt set of heads, new lifters,timing chain and gears, carb..coil

Resolved Question:

Hello: I still have a slight back firing though the carb at around 3000 rpm? This is a 1986 4.3 lt Cobra, I installed a rebuilt set of heads, new lifters,timing chain and gears, carb, points, condensor, coil, sparks plugs and wires etc. The compression is good, fuel pump is good, it has 20 inches of vaccum at idle runs smooth, starts well. The weights in the distributor are clean and lubed, they seem to work fine, because I can see the timing mark advance with the timimg light when I rev it up. Why is it still back firing though carb?????????

P.S. There is a slight bit of play in the distributor shaft and bushing????????
Your thoughts Please??
Submitted: 7 years ago.
Category: Car
Expert:  Tim's Auto Repair replied 7 years ago.


if you are sure the carb is good.....

remove the valve covers and look at the rockers,start the engine and look at the rockers...make sure they all move the same..if not you may have a worn cam shaft


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