Hello to everyone!

My name is Fig. this may be a common question, but I cant seem to find a straight answer about an issue my FIL is having with his RV.

Let me preface my post with this disclosure: I know GM cars and truck, while I have little to no experience working on Ford Vehicles.

That being said, I have been tasked with trying to figure this problem out.

My Father in law has a 2000 E-350 RV with the V10 in it. A few weeks ago, he started having starting issues. I checked all the simple stuff, like fuses or relays. I swapped the horn and fuel pump relays and still nothing. Eventually we determined that if we leave the key on for long enough, we can hear the fuel pump kick on and then the engine can be started. I chalked it up to a sticking pump, and spent the day draining a full tank of fuel, dropping the tank, and replacing the pump, along with both the fuel sock and the fuel filter.

I double checked all connections, and made sure nothing was leaking. I tried firing it up, but the engine only cranks. No fuel delivery to the rail. This was verified by opening the fuel rail pressure test port.

NOW, not even leaving the key on will kick the pump on. I've been doing some digging and apparently there is a fuel pump control module on these vans? I'm at a loss as to what to check next, and could use some insight from more experienced Ford guys.

thanks for any help you send my way!

-Fig

 

This sounds like the fuel pump relay could be slow to latch. I always suggest newbie obtain an EVTM for their year and chassis like this: 2000 E-Series EVTM These are very year and chassis type specific so be aware of that.

Those are quite helpful and allow diagnosing the electrical systems on Ford vans.

As an RV they tend to sit without being started or driven for extended periods of time which is hard on a vehicle, especially on that's 22 years old. We see this here very often.

 

JWA, I should have mentioned that I did install 2 brand new relays for the fuel pump and horn before I replaced the fuel pump. I have also checked all the fuses to ensure that the problem wasn't something simple. I'll look into getting a chassis service manual.

 

Could check the ignition switch (whichever wire it is) that is supposed to supply the fuel pump power?

I was gonna say clogged line, but fuel pump wont turn on so its electrical. Grounded good? checked all grounds?

 

as far as I know all grounds are good. I did suspect that the relay box under the hood might have a grounding issue, but so far it looks OK. I did clean those up just in case.

I was curious to know if the fuel pump is powered through the igniton switch. I know some GM models power too much stuff through the switch and they have had recalls because of that.

 

Hmm.. Well i assume the fuel pump relay gets its power from a power wire off the ignition switch. It wont hurt to add an extra ground or grounds.

If the ignition switch is semi easily cheap/replaceable i would give it a shot. It was a common problem in the old foxbody mustangs. But the ignition switch would burn out and known to cause all kinds of issues.

And if you buy it from oreillys you can probable return it, if you dont damage it while installing or something. So if it doesnt work just a freebie test.

Could also test light the positive fuel pump wire and make sure its getting power. Then trace upwards.

 

I am going to double check to make sure the pump is in fact getting power. I did read somewhere that there is a fuel pump control module somewhere in the cab. Dunno if that might be the culprit.

I also wonder if the inertia safety cutoff could have gone bad? I have no idea hot to test that though. Any thoughts?

 

Do not rule out that you got a bad pump
I know its not easy to access the wiring to the fuel pump on a MH but that is the next step
Verify voltage at the pump
I have never seen a new style Ford ISO relay fail yet
The OP swapped them and that is an adequate test
Good on you for the GM experience OP and for me it is the opposite when I look at my Corvette
Motorhomes usually have only Airtex type pumps and are NOT robust if you get my drift and
I test those AC Delco pumps new out of the box before installing them (after getting a rash of bad ones over the GM parts counter back in the early 2000's)
Good luck, Fig, that's my sons nickname ha ha