Carb issues

[Willy D]

Hey all, got an '88 GW with an '86 360 in it. Been having an issue when I go over even mildly uneven terrain (RR tracks, etc) at say 20mph and up, with the engine shutting off. If I leave it sit for 20 minutes or so, it'll fire right back up and down the road we go. I have rebuilt the Motorcraft 2100 a couple years ago and haven't had issues until recently. Found the fuel pump leaking (mechanical) and replaced it. Ran over an area where they were burying waterlines in town, and covered in dirt and the critter quit, wouldn't start again for about a half hour. It's like it's getting an air bubble that has to work itself out. Any ideas?

[redwoody]

vapor locking. Put electric pump near tank and have no issue since. make sure u have filter with two lines going to carb and other return to tank

[joe]

First suspect would be vapor lock. 2nd would be ign module going south.

[acct21]

My understanding of vapor lock does not include a mechanical ("hitting a bump") component. How does that work?

From watching the boards for a few years, I have been under the impression that periods of running well, mixed with periods of suddenly dying and not restarting (as opposed to hard restarts/hot starts, etc) were a lot of the time related to a stock ICM going bad.

[nograin]

Hey all, got an '88 GW with an '86 360 in it. Been having an issue when I go over even mildly uneven terrain (RR tracks, etc) at say 20mph and up, with the engine shutting off. If I leave it sit for 20 minutes or so, it'll fire right back up and down the road we go. I have rebuilt the Motorcraft 2100 a couple years ago and haven't had issues until recently. Found the fuel pump leaking (mechanical) and replaced it. Ran over an area where they were burying waterlines in town, and covered in dirt and the critter quit, wouldn't start again for about a half hour. It's like it's getting an air bubble that has to work itself out. Any ideas?

Lots of ideas.
But what I would so is try to isolate why it won't run.
Get one of those see through in-line spark testers. Then you'll know if its ignition related.
If it is, look for loose wires first. I've had the terminals in the Ford coil connector loosen up.
Check timing at idle - check idle speed solenoid is working. (saying this 'cause you mentioned it happens at crawling speed.
Check the carb - I was cleaning out my carb every few years and then a couple times a year until I figured out where the 'dirt' was coming from.
Fuel level too low or too high can also cause a stall out. Use your nose and check the spark plugs for clues.
Vapor - shouldn't be an issue - but make sure the vapor return line on th e filter is at the 12 oclock position.

[Willy D]

Thanks for the input, guys. I'll start my quest. Lol

[67GMC]

I would suspect the ignition module if it was me. Especially if it shut down like you turned the key off. A carb issue would be felt more like loss of power, rough running. If it shut off in a second after hitting bump (RR Track), there's no way it was the fuel in my opinion since the bowl has fuel in it to last a few seconds even if you shut the fuel off at the pump. Try re-doing the some of the grounds as well. I carry a spare module with me. They're pretty cheap.