Strange Issue

66Bronco · #1 (**permalink**) 01-08-2012, 12:25 AM

'95 F250, stock with the exception of edge evo and DIY Tymar.
Now, here's the kicker. Always starts, idles perfect, drives great. BUT, over the holidays, I put ~1000 miles on it, and in doing so, discovered that it will randomly shut off. Every time it has happened thus far, I was going 75-80 mph, truck acted as if fuel-starved, shuttered, then died. Pull off the side of the road, crank for approx. 15-30 secs, truck starts and is able to continue under its own power. No CELs, no leaks, no power loss after restart, no nothing. I don't have a clue. Suggestions? Also, all filters new, as well as fresh Delo 400.

White95f250 · #2 (**permalink**) 01-08-2012, 01:03 AM

What's your fuel pressure? Pump could possibly be going out and not being able to keep up. Just a suggestion

66Bronco · #3 (**permalink**) 01-08-2012, 01:12 AM

It's still a mech. pump. No leaks, and it's only ~3 years old.

66Bronco · #4 (**permalink**) 01-08-2012, 01:13 AM

Also, weak fuel pressure would cause hard starting/poor idle quality.

Patrick Feeley · #5 (**permalink**) 01-08-2012, 08:39 AM

You need to check the fuel pressure (and see if it's dropping off significantly) under load. Get a liquid-filled 0-100 psi guage and hose long enough to connect to the schraeder valve on the Fuel Pressure Regulator and route it so you can get the gauge to where you can tape it to the windshield. I had exactly the same symptoms on my 94 (which turned out to be the high pressure side of the fuel pump ... its two-stage). Cheers!

66Bronco · #6 (**permalink**) 01-08-2012, 10:30 AM

I understand that it may be a fuel pressure problem, but if that were the case, wouldn't it stall every time it gets to WOT? As stated, the last time it happened, I had gone ~100 miles at 75-80, then out of no where, it stalled. I can't reproduce the symptom at will, and it's very random. I've been driving it in town for two weeks without issue, and it's only ever done it at freeway speeds after at least half an hour. Also, if the fuel pump is the problem, how would I know? It's a mechanical pump, so if the engine stalls for any reason, you'd lose fuel pressure. Truck's only got 205k miles on it.