Hello Everyone,
Extremely new here and limited mechanical knowledge. I was hoping for help diagnosing what's going on with my truck. Today I was driving down the freeway low on gas and in traffic rushing to get to an appointment, just waiting on my gas light to pop on before resigning myself to getting off the freeway to get gas. The freeway clears up and I'm going 85 trying to make it to my designation on time. Out of nowhere I lose all acceleration and wildly navigate 4 lanes of traffic to make it to the shoulder. I wait about 20 minutes for CAL-Trans thinking I have a bum gas light and I was in fact on-empty this whole time. They show up give me a trickle of gasoline and my truck starts up immediately and I make it to the nearest station to fill a half tank before jumping back on the freeway the last 8 miles to my destination. All goes fine, no noticeable shaking, sounds, smells or lights. I get to a red light at the intersection 2 miles away and with no warning my truck flashes every light on the dash and dies. I throw on my hazards and when the light turns green, fire up the engine and it turns over no problem. I manage to drive to a safe area to asses. Other than these two incidents my truck has been fine. There's no check engine lights or codes and (after waiting on the side of the road for 30 minutes and missing my appointment) I manage to drive it home with no issues. I have a feeling this is fuel pump related but I know there's probably a thousand other things that it might be, and I'd like to test before, either dropping a ton of hours and research into changing a fuel pump myself or paying someone to do it for me. Any advice is appreciated. Thank you.

 

Welcome to the forum

There are no codes for fuel pressure, i.e. pump shutting off on its own
But there are codes if fuel pump loses its 12volts from fuel pump relay, so doesn't sound like an electrical issue for the pump

Dash lights cycling on happens any time key is turned off and on, its called a Bulb Test, if key was on when that happened then 12volts was cut off and then back on at least to the dash, which is an electrical issue, of course

Does the ignition switch, the key, turn on and off smoothly, no stickiness?

I would unplug each fuse in engine fuse box and check its terminals, one at a time, for signs of corrosion, then do each relay in engine fuse box
Also remove BOTH battery cables and clean terminals and cable ends
Its free, lol

There is a Red wire from Battery Positive to the Engine Fuse box, and a Red wire from alternator connected at the same place in engine fuse box, ALL 12volt power for whole vehicle is provided at that one engine fuse box connection


The fuel pump could be failing but usually won't stop once its running, electric motors tend to fail on startup, i.e. they won't start, like a starter motor for the engine, works fine then one day it won't, fuel pumps do that, one day it just won't start up, failing after startup is a longshot

As said if fuel pump lost 12volt power with key on/computer on, that would set a code
But because of the dash lights cycling, if the computer AND fuel pump both lost 12volts then no code, engine just stalls

 

Hey Ron,
Thank you for the response. So as far as my ignition switch, it does turn on and off smoothly. Nothing irregular at all. Though this question did make me remember that a few weeks ago someone tried to steal my truck and jammed a screwdriver into my ignition to do it. They were not successful but I had to remove the plastics and I've been driving with a naked ignition.
Maybe something was damaged in this attempt and I'm dealing with it now?
I tested my battery on the side of the road and it seems like everything was fine. At least in terms of power getting to the alternator. My battery is also pretty new. I'll check all those fuses and relays.
Is there a way I can check my fuel pressure? Or a way to test if my fuel pump is failing?
Also if I do need to replace it, the videos I've found online typically are showing older model rangers, do I need to drop my tank in order to access the pump? Or can I remove my bed to access it more easily? Thank you again for the advice.

 

4.0l SOHC didn't usually have a fuel pressure test port, but you can add one
Not sure what that would tell you though?

If your fuel pump was "weak" you would get "Lean Codes" on both banks of the engine
If pump was just shutting off randomly because of an internal fault then it probably won't start back up reliably and then never start back up, at that point you can spray fuel manually into the engine and if engine starts runs and stalls, it is a fuel pump issue, called 50/50 test, been around since 1890's, lol, time tested

If in a shop with a lift and transmission jack you can lower a gas tank
In a home/driveway setting you tilt up or slide back the bed to access fuel pump assembly

With your other symptoms it doesn't read like a fuel pump issue
As said electric motors don't "recover" well, when they die they die, intermittent is not really a common failure mode

 

The only reason I keep bringing up the fuel pump is I mentioned my concerns to my mechanic who I routinely went to with my older Ranger that had numerous issues pretty regularly and he decided to charge me $80 (after the saying he wouldn't charge me to look at it) to test a battery (fine again) and run my codes (fine again) and he told me I definitely needed a new fuel pump for $1250. I wasn't confident seeing as my car was still (seemingly) running normally and he did no other diagnostic testing and the price seemed outrageous so I left.
Looks like I'll definitely go check all those fuses/relays and hopefully I find something, if not, maybe it was just a strange blip and driving around will give me more clues.
Thanks again for your help

 

Yes, that would be an expensive "guess" on his part, but not expensive for him, just you, lol
A Motorcraft fuel pump assembly is not cheap($400-$600) and most shops wouldn't use anything else because of warranty issues, 3rd party pump assemblies are way way cheaper but can fail within a few months to a year

Its very tough to drive around with an unreliable vehicle, i.e. an intermittent problem
But its sometimes unavoidable until there is an actual full time failure

 

Yes exactly. Well at the very least I checked all my fuses and relays in the engine and they all looked fine. (Swapped out my interior horn/overhead light fuse that I've been meaning to change for two weeks and hadn't gotten around to as well.) Drove around for 45 minutes and everything seems fine. I really do appreciated all your input. We'll see what happens. Thank you!

 

3rd line in post #3: How much damage was done to the contacts inside your ignition switch during the attempted theft?
Can the cylinder/switch part be replaced while leaving the PATS intact?

 

Nothing seemed to be damaged at all other than asthetics. I took the entire switch out and it looked fine so I just put it back in. It seems like their screwdriver just broke and I had to pull the chunk out. But otherwise it seemed fine and I haven't had any issues since.

 

So I lost power again today. I drove about 45 minutes to work this morning (minor traffic) and had no issues. Took me over an hour and a half to get home in pretty bad traffic and just as I got to my house I lost the ability to accelerate again. I pulled over turned off the engine and immediately tried to turn it back on and it wouldn't turn over. Turned it off again waited about 10 minutes and turned it back on and it turned over pretty normally. Drove the rest of the way to my house (about 1.5 miles) and it didn't feel completely normal but it was running with no weird sounds or smells. My check engine light did turn on for a moment at one point but as soon as my engine turned over it turns off.

 

Key on engine at 0 RPMs, the CEL should be ON, that's normal
But you should check it for codes

 

Any guesses what could be going on? Still think something electrical? I feel like maybe something is overheating?

 

Extremely clogged gas filter?
Something weird grounding the spark coil?

 

Just bought a code reader and no codes detected. I found several cut wires under the hood though. Two seem to be going to the top side lights. The green one looks like it runs under the truck. I have no idea where that red one from the fuse box came from and a few ground wires look like they were cut. Maybe this happened during the break in I had. I just didn't notice it as my truck was running seemingly fine?



Grounds?


Lights

 

First 2 pictures, my guess is they went to electric trailer brakes.