1978 305 with rochester 2Gc i believe, its running really werid pls help

[Old man Lucas]

when in park and trying to rev it has a bad misfire and it pops and bangs. when in drive tho, it gose preaty good for the most part exept for the odd time it would stall. the spark plugs are black, but no carbon build up on them( maybe it is carbon or just oil idk ). i did a compersion test on it becuse its not very good at cold start at all i though that it had bad compersion. the driver side had around 140-150 psi, passanger side had 100-130 psi. i´m planning on putting new plug and wires on it when i find the time. if anyone has any idea to what the issue is please let me know.

 

[squaredeal91]

That is a decent variance in compression and 100 is kinda low. Do a vacuum check. And Look under your distributor cap. Look for carbon tracking and check advance spring movement. Also check vacuum advance.
Does it idle smoothly? Or rough. Carb could have issues. But at the end of the day compression is not close to each other.

 

[Snoots]

HEI ignition? Check your dis weights and make sure they aren't sticking.

 

[greyghost]

ck cap, rotor carbon tracking n wire ends loose connections, cap too, n continuity, coil output- pull plug wires 1 at time see how far spark jumps couple inches n crisp snap sound is good. ck vacuum at dist. n advance module holds vacuum , distance actuator travels, ck initial timing 6*-8* no more than 10*