Solved Wouldn’t start after getting gas

[C420sailor]

Just posting a request for info on an interesting issue—more like a mini case study.

99 V8 AWD, 138k. Ran flawlessly, no codes, trims around 0. Took her on the road to my place down south. Got there no problem, drove her around town a few days while i did some work on my 98 Ex down there.

Ian’s rain/wind bands rolled through, and it POURED. the truck sat through that for about 36 hours.

After the storm blew through, I packed it up for the drive back. It started and ran great. Drove it a mile to go get some food, then another 3-4 miles to get gas before leaving town. Shut the truck down at the pump. Pumped 17gal of 87 octane in, and started her back up. Started fine, idled well for 60-90sec, then quit. Attempts to restart were met either with cranking and no fire, or the truck would start and immediately idle horribly (well below idle rpm, surging, popping, clunking, etc) before dying within seconds.

P0320 code, pointing toward CKP sensor.

I looked at the sensor and tone ring. Looked good visually, didn’t remove. No visually apparent damage to wiring. I disconnected and reconnected the negative terminal for the hell of it.

When the truck did fire and run horribly, the tach functioned and I received accurate RPM via OBD2.

I called for a tow, and the truck sat for 45 minutes while I thought about the problem. I could hear the fuel pump prime with key on, but decided to swap the relay anyway. The truck then started, ran horribly for 3-5 seconds, and then smoothed out like nothing had ever happened. I drove it 400 miles home without a single hiccup. I refueled with no issues, so I think that rules out an evap purge valve issue.

I plan to do some checks, namely check fuel pressure, but the trims are still flawless and all other sensor readings look good.

My thoughts are the following:

1) Intermittent CKP/wiring issue
2) Intermittent fuel pump relay
3) Intermittent fuel pump
4) Contaminated fuel

In a vacuum, I’d lean more toward 1 or 2, but the fact that the truck gave it up within two minutes of me pumping fuel into it really makes me think.

Possibly a small amount of water from the storm that took time (45 minutes) to be absorbed into the miscible ethanol?

Thoughts?

 

[Fix4Dirt]

not sure about the v8 but it takes sohc about a 45 seconds to empty the fuel thats in the line. however iirc water is denser than gas so if its separates it separates to the top wonder if there was a water mix in there that was floating round before separating to the top and the fresh gas after diluted the water concentration enough where its negligible? not sure.

 

[Turdle]

Very common for fuel pump to die upon fill up.

Ignore the cheap pumps. Get a quality motorcraft or Bosch replacement

 

[BKennedy]

Bad fuel pump relay, failing fuel pump, water in gas a high probability after all that rain. You already replaced the relay. Maybe there was water in the gas and it didn't have time to separate before you started the engine. I would dump a few bottles of Heet or your favorite water remover in the tank. See if the problem resurfaces before replacing the fuel pump.

I had the fuel pump refuse to run after towing my Explorer 350 miles. I pulled the relay, then put it back, then pushed on the wiring and it came on. Found the loose connection and fixed that.

 

[C420sailor]

The pump is obviously the chief worry, as it’s a PITA. Did it on my other Ex.

Still running great. I’m going to get a fuel pressure gauge on it and report back.

 

[C420sailor]

UPDATE: she reared her ugly head again.

She sat for 3 days. Started beautifully. I drove her for 4-5 miles, and she quit while idling at a light. Was able to get her onto the median. Wouldn’t start. Cycled the ignition and could hear the fuel pump priming. Still wouldn’t start. Let her sit for 30 minutes. Fired right up like nothing happened. Runs great. No codes.

So in both cases she had sat for a few days, started right up, and drove perfectly for 4-5mi before quitting. And in both instances, she fired right up after sitting for 30 or more minutes.

 

[Runnin'OnEmpty]

My guess is it's a failed fuel pump, even though you hear it priming. The carbon brushes wear out and give intermittent contact with the commutator.

 

[C420sailor]

Okay, I’ll order a new pump and sideline her until I can get it done.

One less thing to worry about…but of course that tank is 2/3 full

I gotta see if the PO cut an access hole. If so, I’ll do it from above

 

[C420sailor]

Anyone on here have any poor results with a Delphi pump?

I know Bosch is the go-to here.

I want to replace the entire assembly, not just the pump---I did this in my SOHC with a Motorcraft unit. The MC isn't available for the 5.0, only Delphi...but if Delphi isn't a quality pump, I guess I'll cross my fingers with the Bosch.
I know Bosch makes a great pump, but I don't know the condition of the rest of the assy in there--that's my worry

 

[Mr. Alligator]

What about going back to the PO320 Code? Symptoms could be crankshaft position sensor. Crankcase position sensors cost about $25, far less than a good fuel pump. And the crankcase position sensor is far easier to replace. I think it just takes an 8 mm wrench, a headlamp flashlight, and some patience…. Don’t you trust what your truck is telling you?

Good luck and safe travels.

 

[Fix4Dirt]

Anyone on here have any poor results with a Delphi pump?

I know Bosch is the go-to here.

I want to replace the entire assembly, not just the pump---I did this in my SOHC with a Motorcraft unit. The MC isn't available for the 5.0, only Delphi...but if Delphi isn't a quality pump, I guess I'll cross my fingers with the Bosch.
I know Bosch makes a great pump, but I don't know the condition of the rest of the assy in there--that's my worry

have delphi at the moment, its been fine so far.

 

[C420sailor]

No code this time. Last time, I was still getting valid RPM, which I assume would indicate a good CKP?

The reason I kinda want to throw a pump at it is also for preventative mx. I did the same on my SOHC—pump didn’t fail, but had 215k on it. I have no idea what pump is in there or how old it is. These vehicles are my daily drivers, and I’d rather change one on my terms and know it’s good for another 150-200k than find myself on the side of the road at night with a full tank.

It just feels like fuel to me…gut feeling based on how it ran as it was failing

 

[Mr. Alligator]

Please let us know how you get this resolved. And Good Luck!

 

[Rick]

No code this time. Last time, I was still getting valid RPM, which I assume would indicate a good CKP?

The reason I kinda want to throw a pump at it is also for preventative mx. I did the same on my SOHC—pump didn’t fail, but had 215k on it. I have no idea what pump is in there or how old it is. These vehicles are my daily drivers, and I’d rather change one on my terms and know it’s good for another 150-200k than find myself on the side of the road at night with a full tank.

It just feels like fuel to me…gut feeling based on how it ran as it was failing

I would give this product a try:

Heet - Removes Water, Protects Against Extreme Temps | Gold Eagle

Prevent gas-line freeze up by protecting against temperature extremes and corrosion with HEET antifreeze coolant for 2-cycle, 4-cycle and diesel engines.

www.goldeagle.com

 

[Mbrooks420]

No code this time. Last time, I was still getting valid RPM, which I assume would indicate a good CKP?

The reason I kinda want to throw a pump at it is also for preventative mx. I did the same on my SOHC—pump didn’t fail, but had 215k on it. I have no idea what pump is in there or how old it is. These vehicles are my daily drivers, and I’d rather change one on my terms and know it’s good for another 150-200k than find myself on the side of the road at night with a full tank.

It just feels like fuel to me…gut feeling based on how it ran as it was failing

Fully understand. I usually don’t mind a difficult repair job, but I hate doing them on the vehicles terms.

 

[C420sailor]

Thanks guys, it’s the worst.

I’ll order a CKP too, and throw it in the trunk. Good to have a spare on hand, anyway.

@Rick oddly enough, I picked up a four pack of Heet the other night. Since I think this may be phase separation after it sits, I’m letting the truck sit another few days before I dump some in.

 

[C420sailor]

Update:

Truck sat a couple months. Threw in two bottles Heet. She fired right up, ran great.

For two miles.

Popping, bucking, finally quit. P0320 and 1309. While cranking, showed 0 rpm on my code reader. Let her sit an hour, finally fired up. Got her home.

Now, while cranking, 150-200rpm.

Gotta be the CKP.

 

[C420sailor]

Installed a new CKP. Found wiring to camshaft position sensor that was twisted and taped. No kidding. Cut that trash out and used heat shrink butt connectors.

Some people shouldn’t own tools.

Fingers crossed

 

[Mr. Alligator]

Awesome fix. Well done.

And thanks for posting your solution.

 

[C420sailor]

Confirmed fixed. Let the truck sit a month after replacing the sensor, runs great now, doesn’t quit.