Stalled '99 4.0 SOHC Explorer.

[pl93407]

Hi!
This is my first post on this forum - or any forum, for that matter - so please go easy on me!
This is a great, extensive forum, and I thought you guys might be able to help me out as I'm debugging my car; I've already seen a few posts that sound similar to my problem, and I'll continue to cross-check them again.

The Problem
We're coming back from a ski trip. The car has been snowed-in for 3 days. We drive it for 2 hours without a problem; we're out of the mountains, the road is flat, 60 mph on cruise control when the engine just quits. It's exactly as if we ran out of gas, but there's 10 gallons left in the tank (or so the gage says). There's no sign of fuel leaks under the car. We get the car towed 100 miles to get home (not cheap, nor fun - yes, I will update my AAA membership!!)

Background
- Bought the car new in 1999. It's an Eddie Bauer 4x4 with 4.0 SOHC V6; it now has 150,000 miles.
- I replaced the fuel pump myself a year and a half ago. The pump is an Airtex AFE2296S. I can't remember for certain if it's a returnless unit or not, but I think it is (i.e., only one fuel line comes out of the tank). That's the last problem I've had with the fuel system - or with the car in general actually; it had never failed me before this trip. My Haynes manual seems to suggest there's a pressure regulator on the rail on the LHS of the engine, but I can't see it.
- I added 2 more gallons of fuel, in case the sending unit isn't working right. No joy.
- Listened in the gas tank, with someone turning the ignition accessory ON (but not START): pump primes for about 2 seconds, then stops. It's repeatable.
- There's nothing obviously wrong with the air filter of the intake/throttle body etc.
- Checked the plugs wire with a timing light: the light flashes.
- I don't have a fuel injector NOID light... should I get one?
- Checked the fuel rail pressure: 8 psi. So that doesn't look good...


I guess what I'm hoping to hear is that the fuel filter is probably clogged(?) If I'm wrong about the returnless unit, I guess I could find the regulator, stop the flow downstream of it and see if the pressure rises? That was a friend's suggestion.

I didn't clean the tank when I changed the pump last time. Could that be part of the problem now? How do you properly clean a tank anyway? Should I bring it to a shop?

I know that's a long first post. Thank you for making it this far and I look forward to your comments.

 

[2000StreetRod]

low fuel pressure

You have a returnless fuel system. The fuel pressure at the Shraeder valve should be 60 to 65 psi at all times. The fuel pressure regulator is in the tank. There is also a screen (sock) that filters the fuel from the tank to the pump inlet. There is a fuel pressure damper on the fuel rail. It is located on the driver side near the firewall. Since the pump runs for a few seconds at ignition cycle the problem is probably not electrical. I suggest that you replace the fuel filter if it has been more than 30,000 miles since last replacement. I don't think it will solve your problem but it may make your existing or future pump last longer. Below is a photo of a returnless fuel pump posted by ranger7ltr.

The screen could be clogged, the fuel pressure regulator could be defective, the outlet hose may have split or the clamps may have come loose. Check the outlet fuel hose very carefully for splits. You may be just pumping fuel back into the tank.

 

[Sams01XplrSprt]

welcome pl

 

[BrooklynBay]

Welcome to this forum! I've moved your thread into the stock 95-01 section.

 

[ranger7ltr]

Think back to the fuel pump change...

When you pulled the old pump out of the tank what did the pump filter sock look like? If it was slightly yellowed and dirty looking you MIGHT just have a plugged filter...
If it was dark and rusty looking though you might have a rusty tank and particles of that will kill the pump...

Pull the external filter and catch the fuel that comes out of the inlet side; look at the fuel that the pump is pulling from the tank...
Clear to slightly yellow/light brown inlet fuel is probably just normal dirt and particulate from the tank...

Brown/dark brown/muddy looking fuel is cause to be concerned...Unless the last fuel put in the tank was contaminated the brown stuff is disolved rust...And this passes through the filter sock into the pump and up into the filter which holds it until the filter is changed...

At least you have been driving your truck the entire time...I bought my 99 Sport in 2008 and it had been sitting for over 2 years with a half tank of fuel in it...That plus the metal tank was only half full led to an extremely rusty fuel tank...I changed filters every 2-3 months dealing with the dropping fuel pressure until I changed the tank and the pump for the last time...Oh and I had to change pumps 3 times before I changed the tank.. The rust was passing straight through the pump filter and grinding my pump to death...

The picture is what I drained from the inlet side of the filter each time I changed the filkter before I changed the tank...I hope the fuel from your inlet side of the filter looks better than that...

Let us know what you find...I know I am curious...

 

[my98nnj]

1999. 4.0 SOHC V6; 150,000 miles.

Has any work ever been done to the timing chain components?

 

[pl93407]

Update

This is so great - thanks guys for your input.
I spent three hours on this today. Ok, so I'm not fast.

Did narrow the problem a bit though, and ran into a new (old) one:
- Changed the fuel filter first. Real easy, took 10 minutes: I used my nice fuel line tool from Napa (more on that below. It's not good). It's a 5/16" line at the filter, btw. That's also important.
- Unfortunately, that wasn't the problem (2000StreetRod was right): cranked the engine a few times, and never got over 10 psig at the rail. The car did start for a few seconds though, I was impressed. So it must be the pump, right? I should mention that the fuel I drained from the old filter was filthy - thanks for the comments Ranger7ltr. But it wasn't rust. The old pump I changed a couple of years ago didn't have a discolored sock, and the tank looked real good at the time (and I didn't have it professionally cleaned before changing my pump. That seemed like an overkill, and nobody here mentioned that they recommended doing that... I think a shop 'steams' the inside in a tank clean up. I'm still thinking about it now.) Anyway, this time around, filter fuel was full of black silt, almost like sand. Maybe it's a carbon filter and it's busted somehow? I just changed it and concluded that my pump was bad.
- The pump has only one fuel line, and I think the picture from 2000StreetRod is correct. I say 'I think' because I'm not done yet. After all this time, I couldn't drop the tank. I struggled a great deal last time I changed the pump with the fuel line connector at the pump. I honestly must have spent 2 hours fiddling with it back then with a Ford fuel line tool a friend lent me, until I went to Napa and bought that new tool I'm so proud of (I'm talking about the duck-bill Ford fuel line adapter tool, same that I used on the fuel filter). Back then it worked right away. Well, didn't work so well this time: I just can't get the thing off!! I think the line is 3/8" at the pump, and I have the tool for that. I spent a solid hour doing nothing else but trying to pry it loose, even went back to the 5/16" tool that worked so easily on the filter. No Joy. I have cutaway drawings of the duck-bill fitting, so I understand exactly how the tool is supposed to work, but clearly, I can't use it right. But it worked twice on the fuel filter, right? I don't get why it's not working on the tank. I'm really hoping for some insight on this from you guys.

Right now, my plan is to go back to Napa, by the best fuel pump they have (Bosch?) and a NEW set of Ford fuel line tools.
Wish me luck.

Pat

 

[pl93407]

Hi,
Sorry I didn't address your question earlier.
Yes, the timing belt has been changed on the car, though not by me (I'm pretty sure it's a belt and not a chain). Since the car started briefly, I ruled that out.
Pat