My 1987 Ford F-250 (manual) randomly dies on the road, but can immediately start up. I've recently replaced the fuel pump and it has a new battery. Is there an easy, inexpensive solution to this problem? Thanks!
You are losing either spark or fuel. (Assuming it is not a diesel. You did not specify the engine.)
How old are your spark plugs? Ignition wires? Is your ignition timing set correctly? Have you checked your ignition ballast resistor? Any vacuum leaks? When was your last tune-up? Is your EGR valve working properly?
Looking at the repair manuals at charm.li it appears that all gas engines for that truck use carburetors. Ethanol-laden gas can be rough on old carbs especially if they have not been rebuilt with ethanol-resistant parts. When is the last time your carburetor was rebuilt?
New parts are not necessarily good parts. Have you checked fuel pressure? Changed the filter along with the fuel pump?
It would not be a surprise for a vehicle that old to develop multiple problems that culminate in the engine stalling as well as the other symptoms you are experiencing.
38 year old truck ... I'm gonna say worn out/intermittent ignition switch.
@imperator 135K miles. It's rough to start, have to pump the gas 30 or so times, but it always starts. I have to keep the gas on lightly to warm the engine, or it stalls. but once the engine is warm while parked, the engine stays on. But when I get it on the road, it intermittently stalls, sometimes when slowing to stop, sometimes when accelerating, sometimes while putting steady light pressure on the accelerator.
Does that still sound like the ignition switch?
no it doesn't . Measure your fuel pressure . Did you put in a Ford pump?
@imperator My guess is the mechanic used an aftermarket pump. But it's only got about 500 miles on it.