i have a 1986 trans am with a '85 305 with hedman hedders,elderbrock intake and a non cc qjet flowmaster exhaust just did a tune up ...i was wondering if someone knew why my engine is literally vibrating at 1500+ rpms making my car do the same...i dont know if my cat is clogged or my fuel pump is going or my float is sticking or the timing is off i put it to 8*btdc but its really bad and i have no performance its really slow wont even peel out from a start ...o and if i floor it it will almost shuts down for a bit then kick in and kinda goes..please help its not the u joints because there new and it does it at ideal its like hesitating or sputtering and it happend after i put the intake manafold and non cc qjet on if it helps

 

Was this originally a carb car? What distributor do you have in it? If it was originally a CC carb then the ECM controls the timing thru the stock distributor. If you disconnected the CC carb, the ECM will enter "limp home" mode. Where did you get the carb? If it has been sitting for years it will need to be rebuilt.

 

ya a cc carb 305 orig the distributor is a vacuum advanced 1 or hei the carb is from a resent j/y camaro that got rearend the computers gone i took it out with all the other stuff its straights 60-70s

heres a pic of the distrbutor

 

Make sure you didn't cross up a couple of plug wires. That carb probably needs rebuilding if the ignition is ok.

 

the plug are rite it prob is the carb do u know when a mech fuel pump is goin