Can you simulate the issue by putting the rear wheels on ramps, or have someone jack up the rear while you watch under the hood?
Just thinking it would be easier to trouble shoot if you could look under the hood while the problem is occurring.
Can you simulate the issue by putting the rear wheels on ramps, or have someone jack up the rear while you watch under the hood?
Just thinking it would be easier to trouble shoot if you could look under the hood while the problem is occurring.
Odd to see a Ford with a Carter carb. Anyway, the YF is such a simple thing, there is not a lot can go wrong. The rubber diaphragm accelerator pump would some times leak.
Oh, now that I said that, with the air cleaner off, look down the throat as you work the throttle. You should see a squirt of gas. No squirt could possible cause your problem.
In reply to Dusterbd13 :
I only brought up the Ignition Control Module because of the 'hot stall' issue. I replaced one box on either my '77 or '81. Something in the box would open when hot and once cooled w/ hood open would work again. No internets back then but the Ford truck guy word was to replace, and it worked. I never learned of a test for it though. In your case I wouldn't throw money at replacing it yet, still sounds carb related.
I'd take another look at ignition also. One really odd occurrence was I couldn't find the timing mark on the balancer in the timing sight... nowhere. I eventually found it while shooting the timing light while under the truck, it was at least 120° out of TDC. We figured it was out from the factory or the outer ring had slipped. That was on my '86 IIRC. Winged the timing and it was OK, never paid attention to factory timing marks again. I found TDC and made my own mark.
I did at least three carb rebuild kits on the YF series carbs on my '77, '81 and '86, between 50K and 100K, they always worked for me even w/ kit recommended specs. That was thirty years ago or so tho. That is a long engine so intake manifold leaks may be suspect 40 years later.
I use this for checking carb/ vacuum leaks w/ a digital tach:
Not meaning to load ya up at all on a wild goose chase but this is the kinda stuff I ran into back in the day. Many moon ago.
Re: electrical
From a Saab guy who just chased a fuel issue which turned out to be related to the brake pedal through brake light circuit, how about pulling the brake light fuse and going for a test drive? Maybe the brakes are pulling large current which is dragging down the system voltage below what the coil needs.
What is the spark plug gap? Mixture goes, and they no longer have enough oomph?
Finally, are there maybe parts missing from the carb entirely? Like a high idle stop on the throttle shaft or a slosh bowl around a jet? Have you tried richening the idle mixture?
Like Robbie has, I was going to suggest raising the Idle to 900-1000 Rpm or did you try Getting it warm and Pulling the arm back against the stop to try and Shut it off(the Butterfly) that could mean it's worn and that has been Suggested.
Also there is a check ball in the pump body.
Would ether help with a weak spark? I'd always been told coils either worked or didn't, and believed it until my 2002 got to where it ran fine, but would die and refuse to restart hot. I chased it a lot, but a coil solved it.
I never tried ether when trying to restart, so I don't know whether that working for you tells us it's something else.
Robbie said:Re: electrical
From a Saab guy who just chased a fuel issue which turned out to be related to the brake pedal through brake light circuit, how about pulling the brake light fuse and going for a test drive? Maybe the brakes are pulling large current which is dragging down the system voltage below what the coil needs?
I was going to suggest something similar. I'd unplug the brake switch first, test drive, then the fuse if it still stalls.
Possibly a grounding issue feeding back through a common circuit.
The fact it dies while braking and will pop start, but not via the ignition switch suggests there's an electrical gremlin related to your brake light circuit. (Assuming you apply the brakes while cranking like most people do.)
Did anyone rewire the ignition coil, or engine/starter harness?
If so, it may be missing the ballast resistor /resistor wire going to the coil. They may also have left out the wire from the starter to the coil that bypasses the resistor when cranking.
Without the resistor the coil can overheat causing problems with running at low RPM. The longer dwell at idle makes the coil get hotter at idle, unless there is a resistor inline. higher RPM will have less dwell reducing heat build up in the coil.
The lack of a bypass wire can lead to hot start issues by having a low voltage condition at the coil while cranking. The bypass wire typically runs to the starter solenoid (at least on GM's) to pull a full 12 volts for the coil when cranking, but nothing when the key is off or in run.
It would be a good idea to check the voltage at the ignition coil when cold, hot, and cranking to see if that is contributing to the problem. If you have a low voltage condition, or overheating coil, then the voltage drop from the brake lights might be just enough to cause the stall and hot start difficulty.
In reply to jstand :
A Ballast resistor drops running Voltage to 9 Volts to Keep from Burning up the Points in the Run Position.
you should get the Full 12 V when Cranking , but a Battery Makes 13.2 Volts when Fully Charged and really that is what will Be Going to the Points but for drop From the Starter.
If it was voltage related, id think that running it at idle, in the driveway, with every accessory on full while hitting the brakes would cause the issue. It does not.
Cannot put the back on stands. Its too big to get in my garage.
Ford used some funky stuff in the ignition of this thing. Which means that i actually have to buy parts to test, and the local flaps will barely return electrical parts. Which sucks.
Ransom said:Would ether help with a weak spark?
Yes. Ether needs much less activation energy to ignite.
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