engine stalling problems, need help!
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engine stalling problems, need help!
i have a 77 f250 with the 400, its also an automatic. i rebuilt the carb, replaced the distributor cap, ignition module, plugs and wires. the truck will start up and idle just fine, ive messed with the carb tuning and im pretty sure its good. the truck will idle, rev, warm up and run all day when in park, but when i go to drive it i usually make it a few blocks before the engine will either die or sputter slightly and stall. it then has a little trouble starting again, sometimes itll start up with a little feathering of the gas and sometimes i have to let it sit for a minute or two and itll start back up. any suggestions on what could be causing this? i heard of some vaccuum line to the tranny that i should check, can anyone point me to that or any other possible culprits? thanks for any help!
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What you described reminds me a lot of a similar problem I once had. It did everything you described. Sometimes, after it was warm, I'd turn off the engine and after a few minutes I'd go to start it up. For example, going to a gas station to fill up. The truck would not start up but if I'd let it sit for a few minutes, it would just crank right up. It would also die sitting at idle, but it only would do it after it was at normal operating temp. Turns out, it was a bad distributor. Specifically where the pigtail comes out of the distributor just below the cap. If I moved those wires around just slightly, it would die everytime. I had recently replace the entire distributor so it was warrantied. Replaced it and it has never been a problem since. Crank your truck up and move those wires around and see what happens...
Fleet Owner
Joined: Dec 2009
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From: NorCal
Here are some possible causes:
Idle speed set too low
Vacuum leak
Ignition points or Pertonix gap improperly set
Distributor breaker plate ground wire not installed or tightened
Ignition timing too late
Sticking float or float level set too high
The vacuum line to which you are referring goes to the modulator. If the modulator is bad then you'd have a vacuum leak and also experience tranny fluid loss since it's getting into the combustion cycle. A telltale indication of that is smoke out yer pipes.
Idle speed set too low
Vacuum leak
Ignition points or Pertonix gap improperly set
Distributor breaker plate ground wire not installed or tightened
Ignition timing too late
Sticking float or float level set too high
The vacuum line to which you are referring goes to the modulator. If the modulator is bad then you'd have a vacuum leak and also experience tranny fluid loss since it's getting into the combustion cycle. A telltale indication of that is smoke out yer pipes.
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if i try to drive the truck from a cold start it will run, but have really low power and will not accelerate above 10 or so before it starts cutting out. i didnt take it any more than a half a block like this before i turned around. the problem only seems to be happening when im driving it, otherwise it will idle once warmed up. i do have to keep it running by giving it gas once in awhile the first few minutes of warm up. ive been stumped on this for too long, i wanna get this baby running!
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so i spent today tinkering around with the truck, i checked the wet float level and it was good, then i turned up the idle and drove it around. it lasted a bit longer with the idle set high before it would cut out and it didnt cut out as much with the idle set high as well. i do here a weird sound, almost like a turbo, when the truck is in drive and especially when i barely give it gas like i would be cruising. once i mash the pedal or go more than about 1/4 to 1/2 way the sound disappears.
i have replaced these before or since the problem:
distributor cap
ignition module (on the drivers side above the wheel well, cant remember if this is what its called)
spark plugs
pcv valve
carb rebuild
also there doesnt seem to be a leak, ive sprayed carb cleaner all around the base and it doesnt seem to change the way it runs. i was thinking about changing the fuel filter but i cannot find it. is it located in the fuel pump housing?
any help is appreciated, i really wanna get this thing going again, i miss having it!
i have replaced these before or since the problem:
distributor cap
ignition module (on the drivers side above the wheel well, cant remember if this is what its called)
spark plugs
pcv valve
carb rebuild
also there doesnt seem to be a leak, ive sprayed carb cleaner all around the base and it doesnt seem to change the way it runs. i was thinking about changing the fuel filter but i cannot find it. is it located in the fuel pump housing?
any help is appreciated, i really wanna get this thing going again, i miss having it!
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so i have determined its not anything to do with the distributor, and there are no vacuum leaks and the timing is not the culprit. ive gotten it to the point that i can drive it around town with almost no problems, but once i get to about 50 mph or so the engine will start to cut out and lose power, eventually dying if i dont back off.
someone has got to know whats going on?
someone has got to know whats going on?
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New User
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This seems to be the problem that I am having as well. Have you put a timing light to the guy since replacing the components? Is it still retarded timing?
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so i got it figured out, my timing was off a little and my vacuum advance was broke, but neither of those explained to stalling out at high speeds. in my ford i have 3 gas tanks with a switch next to the driver. the switch must have been shot and sucking air from one of the other gas tanks and cutting out at high speed when the truck needed more fuel. i replaced the inline fuel filter for good measure, adjusted the float, and hooked one gas tank up directly, bypassing the switch. after that the truck is running great!
does it sounds like it is running out of gas? maybe something else?
does it sounds like it is running out of gas? maybe something else?
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