Choke Adjustment 383 4V

[rexus31]

When I built the motor, I used the intake gasket with the block offs so the paint wouldn't burn off the intake. I had the choke adjusted so it would still fully open at temp. After 4,000 miles, I've been having some intermittent stumbling (sometimes stalling) issues and it appears the choke is now not opening all the way at temperature. What's the best way to adjust it with the crossovers blocked? Could the vacuum pod on the carb be the culprit (Carter AFB)?

 

[65sporty]

stove choke in intake? vacuum pod do you mean choke pull off?

 

[rexus31]

stove choke in intake? vacuum pod do you mean choke pull off?

Yes sir. Choke pull off seems to be functioning. I leaned out the stove choke a touch and will see how that does. I also leaned out the idle mixture on the carb a bit.

 

[saforwardlook]

Hey Scott, usually stumbling or occasional stalling is due to a lean condition, not a rich one, so either leaning out the choke setting more or leaning out the idle seems to be the wrong way to go. Even more likely, I wonder if the issue might be an accelerator pump going south - does the stumbling occur on light accels from a stop or tip-in at speed or ?? Does it occur during warm up only or any time - warm or cold? One negative to blocking off the crossover is that the fuel going into the intake manifold is not well atomized since the floor of the intake is not hot, and this leads to stumbling or stalling on accels too. I assume the manifold heat control valve is still operating OK - i.e. not stuck? Or maybe it is always wide open - can't remember what you did?

 

[MrMoparCHP]

I used some fine wire and tied mine open.

Also modern gas tends boil easier, this may play games with you.


Alan

 

[rexus31]

Hey Scott, usually stumbling or occasional stalling is due to a lean condition, not a rich one, so either leaning out the choke setting more or leaning out the idle seems to be the wrong way to go. Even more likely, I wonder if the issue might be an accelerator pump going south - does the stumbling occur on light accels from a stop or tip-in at speed or ?? Does it occur during warm up only or any time - warm or cold? One negative to blocking off the crossover is that the fuel going into the intake manifold is not well atomized since the floor of the intake is not hot, and this leads to stumbling or stalling on accels too. I assume the manifold heat control valve is still operating OK - i.e. not stuck? Or maybe it is always wide open - can't remember what you did?

Hey Steve, thanks for chiming in. Your theory makes sense but the choke not opening all the way still bothers me, especially since it used to. The manifold heat control has been froze open ever since I've owned the car. The stumbling/stalling usually occurs warm at speed (twice) although it has done it once while idling after a few minutes at first start up. When it has happened at speed, I am able to put it in Neutral, start it and continue driving and it has never happened back to back. I wonder if it is an issue with the sender, filter or pump.

 

[D Cluley]

Make sure the linkage between the choke and the fast idle cam is working smoothly. At one point that was hanging up on mine and keeping the choke partially closed.

 

[rexus31]

Make sure the linkage between the choke and the fast idle cam is working smoothly. At one point that was hanging up on mine and keeping the choke partially closed.

Thanks Dan. Where was it hanging up?

 

[saforwardlook]

I doubt either the fuel pump, pickup or filter given the circumstances. I am also wondering why the choke would ever come off with no crossover heat, unless it was adjusted to a really light spring tension. Kind of unusual behavior you are experiencing. No Petronix anymore, right?

 

[rexus31]

I doubt either the fuel pump, pickup or filter given the circumstances. I am also wondering why the choke would ever come off with no crossover heat, unless it was adjusted to a really light spring tension. Kind of unusual behavior you are experiencing. No Petronix anymore, right?

No sir, points. I'm thinking maybe the condenser? I adjusted the choke to accommodate the blocked crossovers. It was opening all the way until recently. Maybe the adjustment moved?

 

[65sporty]

you might be able to get away with a blocked crossover in cali but never in mich. I always thought you needed the crossover with a stove choke regardless of climate for it to operate properly.

 

[MrMoparCHP]

I don't think that is necessarily true, it has more to do with the modern gas.
The gas today evaporates more easily and under operation it boils more easily, the block-off helps to prevent this.

Yes the choke will be effected but that is only at start.


Alan

 

[saforwardlook]

No sir, points. I'm thinking maybe the condenser? I adjusted the choke to accommodate the blocked crossovers. It was opening all the way until recently. Maybe the adjustment moved?

I doubt the condenser is bad, as they usually are either good or bad, not in between and still a pretty rare occurrence. Not sure how to explain the change in choke opening - I assume you are checking it after some long time driving the car, as the only way any spring tension will ease is due to heat transfer from the heads to the intake, since the crossover is blocked. If the choke is significantly closed even after considerable driving, then I would agree the adjustment must have changed/loosened.

 

[rexus31]

If the choke is significantly closed even after considerable driving, then I would agree the adjustment must have changed/loosened.

Could this cause the symptoms I am describing?

 

[saforwardlook]

Could this cause the symptoms I am describing?

Unless it is closed more than halfway, I would say not likely.................................

 

[rexus31]

It was pretty close to halfway.