All Small Six 66' 200 automatic dies when I press the gas pedal

[78_200_C4]

The main clue is:
"I seem to not have the problem when the car is warm."

A lean condition due to fuel falling out of suspension because the log intake is not hot enough to keep the fuel vaporized or the choke is not set rich enough is most likely is the problem.

 

[gserafini]

The main clue is:
"I seem to not have the problem when the car is warm."

A lean condition due to fuel falling out of suspension because the log intake is not hot enough to keep the fuel vaporized or the choke is not set rich enough is most likely is the problem.

Thanks for this, I hadn’t thought about that first issue. I have checked the choke and it appears solid. Stays closed while warming up and then smoothly starts opening until fully open when it’s warm.
I almost want to go back on my words because the issue seems to always come now after the car is warm and has been driving. Then let it sit for a bit after (minutes to an hour) and then the problems arise again. Either doesn’t start or turn over at all, or if it does will die when I hit the gas. I really should say the car only drives good once it’s actually moving and driving on the highway, seems to run great when she lets me get there

 

[78_200_C4]

Thanks for this, I hadn’t thought about that first issue. I have checked the choke and it appears solid. Stays closed while warming up and then smoothly starts opening until fully open when it’s warm.
I almost want to go back on my words because the issue seems to always come now after the car is warm and has been driving. Then let it sit for a bit after (minutes to an hour) and then the problems arise again. Either doesn’t start or turn over at all, or if it does will die when I hit the gas. I really should say the car only drives good once it’s actually moving and driving on the highway, seems to run great when she lets me get there

 

[TrickSix]

Another note on vacuum leak - see photo below - the manifold vacuum port is loose. That adapter doesn't snug in all the way. Or, if i do really tighten it down and it snugs in, then the angle points down and i cannot run the trans-vacuum line to the modulator. Plus that makes it have to run past the headers. Fix for this?
View attachment 21009

So, this vacuum fitting won't tighten up until it is pointing in an unusable direction. Does that mean you have been driving the car with it loose? When you sprayed carb cleaner around the carb looking for vacuum leaks, did you spray around this fitting? FYI, your cobbled together C4 vacuum line is not supposed to be routed down past the exhaust and around the back of the engine. I use good quality fuel line for my vacuum lines, and run them up and over the valve cover to keep them away from the exhaust.

 

[gserafini]

So, this vacuum fitting won't tighten up until it is pointing in an unusable direction. Does that mean you have been driving the car with it loose? When you sprayed carb cleaner around the carb looking for vacuum leaks, did you spray around this fitting? FYI, your cobbled together C4 vacuum line is not supposed to be routed down past the exhaust and around the back of the engine. I use good quality fuel line for my vacuum lines, and run them up and over the valve cover to keep them away from the exhaust.

View attachment 21059

Yes i have been driving with it kinda loose. I did spray this area too and did not hear any surging either. I actually just re-did this line as well. I ran it up over the valve cover like you did here and then behind the engine down to the vac modulator on the trans. I actually replaced that part as well. I got the fitting to seat better on the manifold, but it still is kinda loose

 

[TrickSix]

Did you get a different fitting for the manifold? With a brass elbow you could probably get a nice snug fit at whatever angle you desire. The thread in the intake log is 1/4 npt, and match the barb to whatever ID your C4 vacuum line is, maybe1/4"?

 

[gserafini]

Did you get a different fitting for the manifold? With a brass elbow you could probably get a nice snug fit at whatever angle you desire. The thread in the intake log is 1/4 npt, and match the barb to whatever ID your C4 vacuum line is, maybe1/4"?

No new one yet! Thanks for the sizing I will try this next

 

[sixtseventwo4d]

I almost want to go back on my words because the issue seems to always come now after the car is warm and has been driving. Then let it sit for a bit after (minutes to an hour) and then the problems arise again. Either doesn’t start or turn over at all, or if it does will die when I hit the gas.

This is indicative of an electrical issue.

 

[gserafini]

This is indicative of an electrical issue.

Looking at the ignition switch this week to see if thats it. Also i noticed that my antistall dashspot isnt touching the diaphram. COuld this be causing the stall at a stop and on initial acceleration?

 

[TrickSix]

Stall at stop maybe. Turn the screw in a few turns and see what happens. Stall on acceleration would be from the diaphragm on the other side of the carb, the accelerator pump.

 

[gserafini]

Stall at stop maybe. Turn the screw in a few turns and see what happens. Stall on acceleration would be from the diaphragm on the other side of the carb, the accelerator pump.

Earlier in this thread I have a video showing the accel pump is giving a pretty solid shot of fuel

 

[DON]

Earlier in this thread I have a video showing the accel pump is giving a pretty solid shot of fuel

And it starts as soon as there’s throttle movement?

 

[gserafini]

And it starts as soon as there’s throttle movement?

Hmm i will have to check how instant it is. it might start a milisecond after. I don't think it's instant when I move it a little bit. But its not so delayed that it made me notice it

 

[gserafini]

And it starts as soon as there’s throttle movement?

What would the issue be if it does shoot fuel, but it isn't instant?

 

[DON]

It would hesitate before it takes off

 

[DON]

If it was late enough, the throttle would open and no squirt.

 

[gserafini]

If it was late enough, the throttle would open and no squirt.

It does hesitate at take off sometimes forsure. How can this be adjusted?

 

[Frank]

It does hesitate at take off sometimes forsure. How can this be adjusted?

I'm not familiar with that specific carb. From the pic on post # 29- Are you sure that's an anti stall dashpot? does the arm move toward the plunger in the carb when the throttle is opened, or away from it? If it moves away from it, ok it's the anit-stall.

 

[gserafini]

I'm not familiar with that specific carb. From the pic on post # 29- Are you sure that's an anti stall dashpot? does the arm move toward the plunger in the carb when the throttle is opened, or away from it? If it moves away from it, ok it's the anit-stall.

I think it moves away because that linkage under it runs under the carb and links to accelerator pump and they move together

 

[Frank]

I think it moves away because that linkage under it runs under the carb and links to accelerator pump and they move together

Thanks and sorry for the rabbit trail. I don't know how to tweak the accelerator pump circuit on that model carb. Some carbs there's an adjustment built in, others no. Regardless, the squirt needs to begin at once when the throttle is cracked open. If it's delayed then an off-idle hesitation is the result, worse when engine is cold.