99 5.0, loss of all power on highway, no codes. Sanity Check on path to take

[yeahokay]

Bought a 99 5.0 EB AWD a few months ago, originally had a miss replaced camshaft position sensor and alternator and its ran smooth since then. Last week took it on its longest trip since buying it. 60 miles one way 60 miles back, 20 miles (on the way back) from the house it lost all power on me, before it lost power there were some misses but nothing major. Moved to the shoulder and checked everything I could. There were no check engine lights to help, the engine never died, but in neutral i couldnt even rev passed 1500rpms and it was backfiring. Called tow truck which took forever, and before the tow truck got there I started it back up and it was like nothing happened. Ran smooth. Went ahead and got the tow.

I figure this is an air/fuel/ignition issue. I verified there was no blockage in the air intake. Pulled a plug on both sides, they are not original they are ngk but do not look good looks like they had been exposed to high temps. Im 90% sure the wires are original as they are motocraft and have a date code of 1999.

So I have ordered plugs, motorcraft wires, fuel filter to get started with. I plan to check fuel pressure but i doubt i will see anything while its running well, so I plan to replace the fuel pump but i want to do more tests. I also ordered a better scanner so I can check misses and fuel trims. Last I plan to clean the MAF IAC and throttle body although I doubt that was the issue in this case.

Any idea what else I should look at? The lack of codes is perplexing that it could have that big of an issue without a code, but who knows.

 

[EB4X]

Sounds like a failing fuel pump to me...

 

[C420sailor]

CKP sensor possible

 

[donalds]

Sounds like a fuel pump to me to
Or a clogged filter

 

[yeahokay]

thank you for the replies I’m leaning more towards fuel pump found another post with similar situation. A detail I neglected to mention it was very hot when this happened. In the other thread it was stated that a weak fuel pump has a harder time cooling down with the gas in the tank the hotter the temperature of the gas is. It was probably 104 when it happened, but when the tow truck arrived it had dropped to below 90 and by the time it was home it was 80. So I’ll be replacing the fuel pump as well. Just need to run out some gas since it’s almost a full tank

 

[C420sailor]

If you’re gonna just fire up the parts cannon anyway, start with the cheap and easy ****. That’s what I do when I either can’t or don’t want to diagnose it

Crank position sensor

Unless it’s due for a pump (in other words, you’re on borrowed time), that’s a relatively involved and expensive job.

Sensor is cheap and takes 5-10 minutes

 

[yeahokay]

Im trying not to load the parts cannon, but it does need plugs wires and a fuel filter wont hurt. I have a better scanner coming ill test the crank position sensor I mean during the event it could have been the cps, but thats a random time to decide not work then decide to work imo. As for the fuel pump the person i bought it from owned it since new and stated the fuel pump was replaced at one point but didnt recall when, he said probably over 10 years ago.
edit: ill still test fuel pressure before swapping the pump. If its low at idle speeds, then it needs to be repalced anyways.

 

[C420sailor]

Keep the scanner with you. Next time it craps out, see what the RPM is (via scanner) while cranking

Mine read 0rpm while cranking with zero codes

 

[yeahokay]

I plan on it, my cheap scanner only shows codes which gave me nothing when this happened, so hopefully i can check live data if I can get it to happen again. Ive got 3/4 tank of gas so im hoping I can get it to fail on me again while Im running that out. if I get nothing in that 3/4 tank, ill just do the pump. Ill be sure to test the current crank sensor but its like a $30 part, so ill replace it as well if I can figure this out.

 

[Metalface]

If I could I'd camp out in your garage and give you words of encouragement and hand you protein shakes, because this issue SUCKS BALLS to deal with. I had a similar scare recently. Everything you said about the hotter temp and the pump having a hard time cooling is on point. Crank position sensor scenario was a problem I faced. I was worried I killed my fuel pump. Maybe I kicked it in its ass a little, that's for sure, but the pump was never the problem, it was the damn crank position sensor. The fuel system in our Explorers is a real piece of work, that to be fair isn't worse than most others, but it's complicated for anyone to have to diagnose and fix unless it's crazy obvious.

Because it didn't "entirely shut off" and you just simply could not rev it past 1500 RPM, I have read many instances where that was just a weak or failing pump/filter. This is of course speculating it is a *fuel* issue and not say an *air* issue, like having a super nasty air filter that is so blocked up you can't even get it to rev. Maybe you sucked up a bird somehow lol. Your pump probably did get pretty hot if those factors are all true, though!! I would first suspect a filter, and if the filter is bad, well, time for a new pump since who knows how hard it's been having to work to keep the fuel pressure available. Personally, we've driven our Explorer 6 hours straight before, and then 8 hours in a row, and recently might I add. I had issues the next morning on the day after the 8 hour block trip, after it parked the night before just fine. Except in my instance it was the Crank Position Sensor. That is usually signified by no spark, however, and an obvious read of 0RPM on OBDII Live Data.

You may want to look into doing the magical Floor Access Panel mod, it doesn't interfere with anything, and then it's easy pump replacement from then on out. If you don't have records showing the last time it was replaced, may as well replace it now anyway. Or at least consider doing so. You gotta pull it to check those things out unless you have a gas resistant borescope and a crystal clear tank that isn't full of sediment at the bottom making it impossible to see in depth what's going on in there.

Edit: I forgot to mention. As far as spark plugs.. When I finally pulled mine when I first bought the truck. The electrode was *worn to nothing.* If they are worn, they'll still fire, and still rev. Mine were the original 200,000 mile 26 year old plugs, and they still worked. I feel like the engine compensates heavily for this of course, and doesn't run "right" but shouldn't necessarily limit the RPM. Of course I recognize that you pulled them to check for all you could find, but don't be concerned if they look worn. Just some 2 cents for you!

Please keep us all updated!! And good luck.

 

[Turdle]

Sounds exactly like what happened to us going down vail pass with 1/4 tank of fuel. Fuel starvation.

 

[Metalface]

Just double checked -- you never mentioned (unless I've got something wrong with me) how much the gauge said and how much of a grade you were on when this happened. Was it uphill, downhill, flat? Is the fuel gauge reliable? Mine is, but my friend's isn't. How much fuel did you have in the tank? Turdle has a good point.

 

[yeahokay]

Good point, This actually happened at construction and as i was slowing down to an almost complete stop it was when I went to speed back up that power was gone. Ath this point in the road it was flat. I did climb a very steep grade about 1 mile before this no real problems, im not sure if I mentioned it but maybe 5 miles before this a miss did start happening. The gas tank was between 3/4 and 7/8 full. Full gauge has been reliable, and so has that display on the console it's pretty acurate.

 

[Metalface]

Hmmmmmmmmmmmmmmmmmmmmmmm. Ok.
I think if it didn't act funny on the hill, and if the gauge is reliable and the tank was at least over half. Then it's probably just the pump; filter; etc (fuel delivery) being tired given everything else that has been addressed.
So probably yeah.. I guess let's go for checking the actual fuel system itself first starting from point B (not A lol) being the filter, then the lines, then the pump and while at it with the pump check the tank for nasty stuff, sludge, sediment, all that.

Is it really rusty under there? Worth asking.

 

[410Fortune]

Classic weak fuel
Pump with the returnless system they will run good with 45 psi pressure until they don’t. They need 64 psi. The fact that it runs fine once cooled off points to a weak pump… we see this alot
Plan to replace
Pump Strainer and filter
I
Like Bosch pumps when they are available otherwise Delphi or… stay away from duralast and airtex

 

[Metalface]

Classic weak fuel
Pump with the returnless system they will run good with 45 psi pressure until they don’t. They need 64 psi. The fact that it runs fine once cooled off points to a weak pump… we see this alot
Plan to replace
Pump Strainer and filter
I
Like Bosch pumps when they are available otherwise Delphi or… stay away from duralast and airtex

I speak for many when I say Duralast is a convenience item. I've never had good luck with Duralast and I've bought more Duaralast parts than I can even imagine. If they work long term it's because you got lucky. Most of it is remanufactured/refurbished BS. I don't know about their fuel pumps since I knew to steer clear from Autozone parts that were major major. I'll do a brake caliper here or there or a rotor, no way am I gonna trust a pump from Autozone. I just don't have that level of balls.

 

[EB4X]

Carter fuel pumps are good as well...

 

[donalds]

I ran a carter pump in mine until I did engine work

 

[C420sailor]

Duralast is ****. Just about any parts chain’s house brand, with few exceptions, is junk. When I first got my Ex, I put Pepboys ball joints in. They lasted 5,000mi, no kidding. Groaning like an old man. Absolute junk.

 

[yeahokay]

i can find delphi locally so ill go with that. Im still going to run the tank out to make my life easier (and to see if I can get it to happen again and look at all the data i can). Ill be doing plugs, wires and fuel filter tomorrow or saturday, hopefully the fuel filter will give me an idea of what the inside of the tank is like. Rust is normal for an almost 24 year old car nothing major at all. Tank does not look rusted the few times I have been under it.