Intermittent stalling at operating temperature.

[Ichiban_Al]

Hey everyone. My name is Alex, its my first post here. Happy to be part of the community.

A little background on my car: Its a 1964 Falcon Wagon four door, 170ci six with ford-o-matic. I bought it off my boss who drove it daily in the late 90's, and then parked it in 2001 in one of our dirty old storage warehouses. It sat there for 15 years (with dollies under the wheels so the warehouse manager could move it around) until I made an offer on it this summer and got it out of there.

I brought it to my garage, cleaned it up, replaced the leaking fuel tank, put on a new fuel sender, fuel filter, replaced the fuel pump, rebuilt the carburetor, got a new battery, and fired it up. It started right up, so I replaced the fluids, tuned the carb to a point where it was idling steadily, got the brakes working well and started driving.

At this stage, the car runs great when its cold, with the exception of a slight hesitation off idle, which I chalk up to an improperly adjusted accelerator pump. Ive been driving it to and from work, which is a 15 minute drive and its been performing flawlessly.

However, when the car warms up to operating temperature, after about 20-30 minutes of around town city traffic driving, I begin to get intermittent stalls. Almost entirely when accelerating from a stop, or going around corners. It doesnt happen at every corner and every stop, just some. It happens enough to make it difficult to drive in city stop and go traffic, which is 75% of the driving I do. Sometimes I can save the car from dying after it stalls by pumping the accelerator rapidly. Also, after the car begins stalling, when I restart it, it sometimes stalls again when I drop it into gear and load the engine.

Important note, this does not happen on the highway. I can drive for an hour and a half on the highway at a constant speed and the car will never stall. Even if I stop in traffic for 5 to 10 minutes, it performs great on the highway.

Ive narrowed it down to a few possible things:

1) Vapor lock: is the fuel boiling in the lines when the engine warms up? Im leaning away from this possibility because the car starts right up again after stalling (Usually have to press the pedal to the floor while starting to get it going)

2) Rich idle mixture: Am I dumping too much gas into the intake, and maybe its pooling up when the car is stopped?

3) Improper float hight: Maybe theres too much (or too little) fuel in the bowl, and im stalling around turns and dead starts because of it?

Could it be an ignition related thing? Ive read about how a bad coil could act up under heat and cause symptoms like this.

Id be grateful for any advice or any leads in the right direction. Thanks in advance. Im loving the Falcon so far, despite the issues.

Heres some photos:

[Bill Pierce]

Nice little wagon.

I would check ignition timing. May need advanced a bit. That could also be the problem with your stumble on acceleration.

[Luva65wagon]

Very cool wagon. You're fortunate it was stored inside all those years.

I'd suggest also checking the float level as well as looking down inside the carb while running and accelerate it (wear safety glasses, just in case). If the accelerator pump in working you should see an instant squirt of fuel down the throat of the carb. Anything that appears hesitant, or near part-throttle before it squirts could just mean the pump travel lever (not sure what carb you have) may need to be tweaked to get it to pump as fast as you push on the pedal. Because the accelerator pump requires having the correct float level, it's worth doing that first just to be sure. Accelerator pump is nearly unused during steady-state travel, so freeway use wouldn't reveal an issue there, unless you were trying to pass someone.

Welcome, and looking forward to watching your progress.

[Ichiban_Al]

Nice little wagon.

I would check ignition timing. May need advanced a bit. That could also be the problem with your stumble on acceleration.


So I grabbed a timing gun today and went at it. I understand the process of adjusting the timing, however I am having extreme difficulty seeing a timing mark on the balancer when the strobe fires. Any tips on finding it or what I should be looking for? What RPM should I be setting the timing at, and what is the normal idle (in park) RPM for 170 with ford-o-matic? What should it drop to when I load the engine in drive? Im asking now because the light has a tach so its helpful in doing my adjustments. Thanks so far for your help.


Very cool wagon. You're fortunate it was stored inside all those years.

I'd suggest also checking the float level as well as looking down inside the carb while running and accelerate it (wear safety glasses, just in case). If the accelerator pump in working you should see an instant squirt of fuel down the throat of the carb. Anything that appears hesitant, or near part-throttle before it squirts could just mean the pump travel lever (not sure what carb you have) may need to be tweaked to get it to pump as fast as you push on the pedal. Because the accelerator pump requires having the correct float level, it's worth doing that first just to be sure. Accelerator pump is nearly unused during steady-state travel, so freeway use wouldn't reveal an issue there, unless you were trying to pass someone.

Welcome, and looking forward to watching your progress.

Thanks! I get a pretty strong stream right away when I hit the accelerator. Also, last time I had the carb open I set the float to 1" which is spec for this Autolite 1100 with rubber/plastic float. Even when I hit it hard on the highway to pass I get no hesitation.

[Bill Pierce]

So I grabbed a timing gun today and went at it. I understand the process of adjusting the timing, however I am having extreme difficulty seeing a timing mark on the balancer when the strobe fires. Any tips on finding it or what I should be looking for? What RPM should I be setting the timing at, and what is the normal idle (in park) RPM for 170 with ford-o-matic? What should it drop to when I load the engine in drive? Im asking now because the light has a tach so its helpful in doing my adjustments.

I would turn the engine over by hand or with a wrench to TDC and mark the damper with a paint pen so you have a good mark. That will make it easier to see.

Initial timing should be 12 DEG for a automatic. I found setting timing on the highest vacuum helpful. Then you can listen for ping and back off as needed.

Set your idle at about 650 RPM once you get it running right.

[Ichiban_Al]

I would turn the engine over by hand or with a wrench to TDC and mark the damper with a paint pen so you have a good mark. That will make it easier to see.

Initial timing should be 12 DEG for a automatic. I found setting timing on the highest vacuum helpful. Then you can listen for ping and back off as needed.

Set your idle at about 650 RPM once you get it running right.

So that's 12 degrees with the vaccuum line from the carb removed?

[Bill Pierce]

Yes, you need a manual. There is one posted here http://www.tffn.net. it's a factory Ford manual. If your car is still stock all the specs are there.

I told you the wrong idle speed., the manual says 550-600 rpm.

[Luva65wagon]

Having a manual is great, but as for timing do what Bill mentioned earlier, which was to adjust timing to the highest vacuum reading and then drive it, pulling hills etc. If it pings, retard the timing a degree at a time until the pinging stops. This will accommodate for the fact that fuels today are not the fuels of 1961. You'll do better this way than using what the manual says, though it's still a good starting point if you're doing a rebuild or something.

[Ichiban_Al]

Thanks for the responses guys. I have the shop manual, it's just that some descriptions in there are a little short worded and don't go too far into detail. It's nice to hear it directly from those who have experienced it first hand, so thanks for the descriptions they've helped.

So today I had off from work so I was able to try a combination of things. First I put in a new air filter since the old one had collected 15 years of dust. This probably didn't change much but I felt it was good to do anyway.

When I rebuilt the carb I left the old float needle and seat in because I thought they looked pretty good, but now I compared to the new ones in the rebuild kit and they are noticeably different. I installed the ones from the kit. This may have eliminated my intermittent stalling problem. But I won't know for sure because I kind of went against an important rule of tuning, which is to only adjust one thing at a time to see the results it produces. That's obviously the best troubleshooting method but I was impatient and tried to adjust the timing again at the same time. At this point I wasn't stalling anymore but the acceleration was very hesitant off stops, so I advanced the timing until the stumble went away and the car began to run smoother and became more responsive. Since I still couldn't locate the timing mark, I adjusted by feel gradually until I felt good about the performance.


It seems better. I'm going to drive it for a few days and see how it acts. I know it's not really the right way to do the timing, but the car is acting better for sure. Not exactly perfect but I'm getting there. I'll let you guys know if stalling returns.

[Bill Pierce]

Good News!

To be honest I mostly just tune by ear anymore. Like I said before I use a vacuum gauge and adjust for the highest manifold vacuum then drive up a hill with my foot to the floor and listen for ping. If I hear any I retard timing until it goes away.

I would encourage you to join the national falcon club as well as the local club here as there is a ton of information and good people willing to give you a hand.

Have fun :)