i know the tell tale hot start issues of a bad ignition module. now how about one thats starting to go? lately ive been getting some ignition related issues. as soon as i get to about 4k in second gear, the engine just loses all power and starts to back fire into the intake. if i let off and get back on, it still there. doesnt do it in first gear. i also didnt do it if i immediatly got on the highway. seems to do it it now after a good heat soak. bumped the base timing up from 6* to 10* and made it worse. ignition is advancing to about 18-22* when doing a snap throttle test. doesnt do it unless the engine is under load, and i dont want to just start throwing parts at it. i was going to try again tomorrow and see if unplugging the knock sensor had any change

 

Unplugging the KS will just cause the spark timing to be retarded. The engine may be starving for fuel under load at high RPM. Check the fuel pressure before changing parts.

 

i was thinking fuel myself being that i have a new, but stock fuel pump. however letting off would rebuild the pressure. but it only does it after a good heat soak. i was working on it earlier today before it started raining and found the cap terminals to have a lot of white crud build up. cleaned it off, will try it out later.

 

cleaned off the cap, no change. runs a little better. started messing around. launching the car will produce the issue each time. rolling on from 30 or 40 will not. it still dies out around 5k, but goes strong into third at 90. im thinking a combination of high fuel demands, a non baffled tank, and a fuel level of right around half

now the problem is finding a fuel pressure tester with a hose long enough to enter the cabin

 

If you are completely convinced timing, and ignition aren't the issue, I would agree it could be air/fuel delivery. Is there any evidence of vacuum issues, or sensors adjusting a/f, or timing when you don't want it to?

 

i wasnt convinced it was timing, but had some of the signs of the module going bad. i figured now it was the fuel pump because any time i hold it sideways when the fuel is around half, it creates the same issue (evidenced in video in sig). i dont think the fuel gauge is accurate either. i need to get a scan tool for it though as the gauge cluster is inop and cant do a blink code reading.

 

Sounds like you head down the right path but if your fuel pressure shows ok I would check the rotor cap for signes of burn through to distributor shaft and try a different coil. Without a scope it can be tuff to determine if a underload miss is spark failure or lean fuel.

 

the cap and rotor only had about 5-6k miles on them, but also sat for two years. the coil has even less, and is a pertronix high voltage unit. im about 85% sure its fuel related, but can't afford to do anything with it now.

 

im sold on it being something awry in the tank. filled it up and now it doesnt do it. i bet the hose clamp near the strainer is loose or dried and cracked while it sat. oh well, it wont be hard to fix and upgrade