I’m having an issue with my 85 w/12a. Car starts and idles fine. When I blip the throttle to begin accelerating the engine stumbles. Once I am above around 2000 rpm the car drives as expected but doesn’t seem to like lower rpm quick throttle applications. Definitely most notable just above idle. Problem seems to worsen as the engine warms up. I have confirmed that the accelerator pump is injecting fuel out of both ports with throttle application. Where should I focus my attention on next?

 

I’ve checked compression and it’s good. I’ve checked coils, plug wires, accelerator pump. It’s pulling 18” of vacuum at idle…

not sure where else to look.

 

Are you running stock carb/intake or is it aftermarket? Has it always behaved this way or is this something that has developed over time?

 

Stock intake and Carb. Happened pretty suddenly on the way to the storage location where car is stored for winter. Was driving normally and then began to stall if I drove it as I typically did. Had to slowly bring the revs up before releasing the clutch, as opposed to quick blip before clutch release. The quick blip would cause it to stumble and sometimes stall.

i also just noticed that my exhaust temps were quite different on the front and rear rotor. Egt at idle was about 350 degrees in the front rotor primary pipe and about 550 for the rear.

 

I just started having this same issue about 2wks ago. I checked all the same things you did. Still haven’t figured it out yet. The only difference with my car is it has a Racingbeat Holley Carburetor and intake manifold kit.