I have been trying to figure out why my 66 fastback is running horrible. the car wont stay running, and sounds aweful until about 2500 rpms, when it sounds normal again? i have checked all wires, and timing. could it possibly be the coil? or could it be the gas i put in it? it has about 1/4 tank left, and it has 92 octane in it? the engine has 10.5:1 compression? just tryin to find out possible causes for this? please let me know what you think. thanks again for all the help!
Tyler

 

have you checked to see if the vacuum advance one the distributor is working properly?

while the car is idling pull the vacuum hose off the base of the carb. and suck on it, if nothing happens then i bet thats what your problem is

 

That's going to taste pretty bad!!!

 

Get out your multi-meter to check the voltage at the coil. Should be somewhere over 8. If you are still running points, check it to see if they are burned.

 

i have the vacuum advance plugged? should i? i was told to plug up both the distributor and carb advance holes?

 

Are you asking advice on how to set your timing and tune your car?

 

no, i timed and tuned it with the holes closed. i just wanted to make sure it is ok like that

 

After you tune the engine, plug all the vacuuum hoses back in. In other words plug all your vacuum hoses back in after you have timed the engine.