Trying to set timing. At 6, 8, 10, 12 and the EST plugged back in it idles smooth but if i try to give it too much gas it will stumble and backfire if i dont let off. With the timing advance way out it will idle like crap with the EST plugged in which is expected but throttle responds and doesn't backfire/stumble. It would be great if i could take the throttle response and combine it with smooth idle.

The distributor is new and have checked firing order. TPS voltage is at .5 at idle and goes up past 4.5 at WOT. It is also much harder to start when the timing is set to where it should be. When it advanced it starts right up.

What could cause this? Plug wires checked out ok. Any other causes i should check out?

Turned out to be the plugs and wires. Changed em out and she runs beautifully again. Thanks Guys

 

Try spinning the the distributer around 180 degrees and time it again.

 

Ive driven the car. Would I even be able to achieve a smooth idle with the dist 180 out?

 

I've seen smooth idles with dist 180 out before. I'd find TDC compression stroke, and make sure rotor points to #1 wire, then double check firing order again.

 

Could it possibly be a weak ignition coil? I used a screw driver and watched the spark jump from it to a bolt under the hood. The spark was a yellow color. Correct me if i'm wrong but it should be a nice bright blue spark.

 

If its carbed I wouldint spin the dis. 180 I've done it and it just blew a cloud of smoke out the garb when I tried to start it, the intake/exhaust phases for the pistons will be opposite of the carb. If its fuel injected idk what will happen