Stalls While Driving
Hello Everyone! I'm a new member and new to the RV Life. I recently purchased a 1991 E-350 (7.5L Engine). It has 62K miles. Runs great! However, on a recent trip it stalled (choked) while I was on ...
Forum Discussion
Assuming your engine is fuel injected (460s got EFI in the late 80s and it was relatively higher pressure, for the time, not like early low pressure throttle body injected engines).
This alone should all but eliminate vapor lock.
However, there are several other things that could present as the same symtoms.
First though, if it is vapor lock, I believe the boiling point of high octane is a bit higher than low octane gas, so cheap experiment to try a tank of premium, or even premium pure gas.
But I still think vapor lock is about impossible with a 40-50psi fuel system.
Other things:
Old van, old fuel pump? One the fuel pump is heat soaked and that is exaggerated by high ambient temps and also by low fuel levels (less fuel cooling if less volume), it could be losing pressure or shorting out due to heat soak (expansion).
Similarly, it possible for the same to happen to the fuel pump relay although less likely, I think?
Also possible that the ECM is shorting out and losing contact when very heat soaked (had this happen to a boat ECM once).
Is the fuel pump still running (you can hear it) after it stalls?
If not, then I'd lean towards ECM/relay issues, but on a 30 year old vehicle, new relays, fuel pump and filter is not actually throwing parts at a problem, its preventative maintenance.
Bottom line, less likely to be vapor lock on an EFI system than it is to be some other issue.
This alone should all but eliminate vapor lock.
However, there are several other things that could present as the same symtoms.
First though, if it is vapor lock, I believe the boiling point of high octane is a bit higher than low octane gas, so cheap experiment to try a tank of premium, or even premium pure gas.
But I still think vapor lock is about impossible with a 40-50psi fuel system.
Other things:
Old van, old fuel pump? One the fuel pump is heat soaked and that is exaggerated by high ambient temps and also by low fuel levels (less fuel cooling if less volume), it could be losing pressure or shorting out due to heat soak (expansion).
Similarly, it possible for the same to happen to the fuel pump relay although less likely, I think?
Also possible that the ECM is shorting out and losing contact when very heat soaked (had this happen to a boat ECM once).
Is the fuel pump still running (you can hear it) after it stalls?
If not, then I'd lean towards ECM/relay issues, but on a 30 year old vehicle, new relays, fuel pump and filter is not actually throwing parts at a problem, its preventative maintenance.
Bottom line, less likely to be vapor lock on an EFI system than it is to be some other issue.
