I have a 2001 E150 van, 4.6 with 79k miles...

About a month ago it suddenly started exhibiting a "long start" issue; always started fine cold, but after *driving* a little (idling doesn't count) and turning it off, it would:

-Up to 30-45 minutes, start fine
-after 30-45 minutes take a few extra cranks to start.
-between 1-2 hrs, take even more cranks to start (never had to keep trying, still started on first attempt, but would turn 10+ times before firing)
-after 3 hrs, start just fine again

To me, this sounded like a fuel pressure issue. It was very consistent, and very predictable...

Then one day recently, everything randomized... sometimes I'd get a long start after it sat over night (or more than 3hrs), sometimes it would start fine after 1.5 hours; the only thing that remained consistent is that it still always starts fine for 20-30 minutes after driving it...

Since this happened, I started listening for the fuel pump; I don't always hear it buzz... but just because it doesn't, doesn't always mean it won't start easily...

With all this said, it has never not-started, nor has it died. Sometimes I do think the power feels a little down sometimes, and it does *seem* to have a miss or hesitation on occasion, but sometimes I wonder if it is just in my head, and I am just feeling the OD kicking in and out...

I did replace the fuel pump relay just because it was only $13 and it certainly won't hurt in a 17 yr old van, and I picked up a fuel pump, but I'm reluctant to spend a day tackling that if it isn't needed... I don't have a fuel pressure gauge, but being that this is intermittent, I'm not sure it would do me any good anyway... Another thought is the fuel pressure regulator; anyone have one go out before?

Other thoughts?

 

There is a check valve built into the fuel pump assembly that keeps the line pressurized after the key is turned off. If this check valve is leaking then the pressure is bleeding off back into the tank. The lack of immediate fuel pressure is what can cause the long start. To test this theory, before starting turn the key on for 2 seconds, then off, then on for 2 seconds, then off, then try and start it. If it fires right up each time you do this the check valve is leaking.

 

Very interesting, I'll play with that. Of course, this means I would need the whole assembly, not just the motor I picked up...

Should I hear the pump run every time I turn it on? Sometimes when I cycle the key, it hums every time, sometimes it doesn't. I haven't found a consistent pattern with the hum/no hum/start relationship yet...

 

Okay, I'm finding conflicting info on the check valve for the 4.6; for some, it is in the tank, others have it outside the tank near the frame rail or at the fuel rail near the regulator... also, for in-tank, I'm reading that it's in the fuel pump assembly ($200), others say it is contained in the pump itself ($80 and was in stock) and the assembly is not necessary unless I need the float sender... this jives with other pumps I've done on GM and Toyota; I have an assembly from my old Astro van than doesn't appear to have any check valves...

Is there a way to confirm where exactly the valve is for this specific application, without tearing everything down first?

 

Not really. But if it were me and I was sitting on a 16-year old pump, I would just get a whole assembly. Otherwise you could be pulling it out again for something else in the not to distant future.

 

Found out the valve is indeed in the pump itself, and also found a guy with a gauge yesterday; it's the check valve causing the bleed-off (almost immediate), and the pump itself is a little week too. The store doesn't have the full assembly, but this needs to be done today; it's the last Saturday I have free before a 2k mile road trip so it'll be fine for now. There's nothing the the rest of the assembly that will leave me stranded.

I need to get to work...

 

So it was a success. Not too bad a job, especially with a less than a 1/4 tank. I was surprised to be done in well under 4 hours, including the learning curve; I think I could knock it out in 2 if I had to do it again. Didn't even have to remove the tank completely; just lowered it with motorcycle straps and tilted it to remove the pump assembly... which BTW, is a BEAST compared to others I've done/seen, and simpler. The assembly in this van is all steel, and should last forever; none of that over-complicated, fragile plastic crap in my GM cars/trucks/vans. No reason to replace the whole assembly unless for some reason you are having gauge issues.

 

I love a good diagnosis.

 

Yes that's good time for your first attempt, especially when removing something that's been in place for over 16 years.

 

Well, it certainly helped that it's lived in central Texas all it's 78k mile life, as a secondary vehicle kept in a garage But, I'm betting it's probably those same extended periods of un-use that led to its low mileage failure.

The ability to just tilt the tank without removing it was key as well; it would have taken much longer to actually pull the tank all the way out and put it back in. Wouldn't have been able to do that with a more square tank (this one is very long and narrow)