1994 E350 5.8L sometimes won't start unless battery is reset

The problem occurs intermittently, with no apparent pattern (except maybe high humidity?). Battery & starter are good (engine cranks, but just doesn't run), and fuel pump is audibly whirring. Sometimes re-trying works, but after 4 or 5 tries with no luck, the only thing that consistently gets the engine running is to disconnect the battery for a minute and re-connect it.

I bought a new fuel filter, but haven't installed it as I haven't been able to disconnect the "quick disconnect" fuel hoses to the old fuel filter.

Any ideas would be greatly appreciated!

I had an auto shop look at it for 2 full days and, of course, it started just fine every time! I had them go ahead and replace the fuel filter anyway. The mechanic had a great suggestion which worked:

About a week later, the van wouldn't start again like before. While having someone cranking the engine, I [gently] banged on the underside of the fuel tank with a stick and the van started and ran just fine!

SUSPECT: intermittently sticking fuel pump. Before spending $500 to replace it, I'd like to duplicate the problem. Does anyone have any other low cost ideas to try?

If banging helps out 2 or 3 times buy a new pump.

Well, the problem recurred yesterday, but this time banging on the tank did NOT help, and doing the battery reset did NOT help either! I tried both tricks separately and together at least twice, but still the engine wouldn't run.

We left it alone for 3 hours and were going to call a tow truck, but tried one more time--and it started right up! Maybe it's humidity-related, since it was somewhat foggy earlier in the morning, and noticeably clearer when we came back and it started up. Any more ideas would be greatly appreciated!!!!!

Check the relay for the eec and fuel pump. If your finger is on them you can feel them click. Some of the relays are on the drivers side fender and some grounds are in this area.I'm unsure the year they changed but they used to have a computer ground in the right side kick panel pass side. A loose ground will cause problems.
Some fords have a primer pump in the tank and an external pump along side the frame in the back. Use a test light or DVOM and check for voltage to the fuel pump.

Thanks for the suggestions, but another repair shop believes they traced the problem to a bad cable connector to the ignition coil. Here's what's happened:

A new and/or related problem had developed--sometimes while driving, the engine would suddenly stop running (very disconcerting and dangerous!). After sitting awhile, the engine starts right up. Lately, it wouldn't start up at all (i.e., still cranks, but engine doesn't run), and had to be towed twice. I had already replaced the distributor cap, rotor, ignition coil, and Ignition Control Module (which did test out bad). Then I rigged up a wire to check for sparks from the coil--and didn't get any sparks.

The first tow to the repair shop: they repaired the hot wire of the cable which runs from the ICM to the ignition coil (where the connector plugs into the coil). Computer diagnostics indicated no problem with the fuel system. I drove ten miles and the same problem occurred: it suddenly stopped running while driving, and wouldn't restart.

Second tow to the repair shop: supposedly the same problem area, so this time they replaced the connector instead of trying to repair it. Time will tell if this is really fixed; I will be driving the van a lot to be very sure the problem is resolved.

Watch it and if it won't start put a test light on the coil negative. It should blink if it has a good pickup in the dist. and power to the coil. Follow power to the coil. On my T-B 5.0 liter I had a bad ignition coil and also a loose ground for the eec relay. just like yours it would start most of the time but if it didn't start after sitting a while it wouldn't start.
Go to http://www.alldata.com/ buy a years subscription $25.00 with a discount for other vehicles.
They have good electrical diagrams and show where all grounds terminate.
From past experience this is a good investment as fords have a lot of electrical problems on older vehicles.

The engine still quit while driving! After a third tow to the repair shop, I think they finally found a third problem (and hopefully final) which was causing the intermittent starting/running. Besides the bad ICM and the bad cable/connector at the ignition coil, the shaft of the distributor would sometimes not turn (due to it being OEM and worn after 14 years, I understand the shaft/gear was disengaging when it reached a certain temperature), thereby preventing the rotor from sending the spark to any sparkplugs.

With the new distributor, the van has been starting and running just fine so far. This latest repair fits perfectly with the symptoms of the problem; it didn't behave like a fuel pump/relay issue except for maybe one time out of a dozen or more incidents. The shop says they are 99.99% sure they fixed it, because they actually saw the distributor shaft/rotor not turn when the engine wouldn't run. Time will tell.....

I'm almost sure the pickup in the distributor had an electrical fault. To change this requires a special puller. If a shop doesn't have one they buy a rebuilt distributor. The gear on the bottom of the distributor is steel Dodge used some plastic gears in the 1997 & up dodges. I've never known Ford to use plastic gears but some rebuilder may have. This gear also drives the oil pump and you would loose oil pressure if the gear strips. The gear has a pin in it and won't go through the distributor base. If it picked up you also would need both a rotor and distributor cap. To finish the job. I'm glad they fixed the problem but do think they should be honest with you.