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· Registered
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Discussion Starter · #1 ·
I originally posted this in the "General Questions" by accident last week. I didn't get any replies over there, so I thought I would try over hear.

The last two weeks my truck has been acting like it's running out fuel and will eventually die if I don't pull over. If I do pull over while it's still running, it will idle roughly for several minutes but will eventually smooth out and I am able to continue on for about 10 minutes before it happens again. If it dies, it will not start unless I let it sit for 10-15 minutes.

The first time this occurred was after I ran out of fuel a few blocks away from my house. I was driving for approximately 20 minutes or so after putting approximately 12 gallons in it and it started acting like it was running out of fuel again. I was able to limp into a parking lot with it barely running. I crawled underneath my truck to look at my pre-pump filter and saw that it was only half filled with fuel and was filled with a bunch of large particles:
View attachment 98601

(My truck was infested with brown widows (an invasive species) and I believe a few made their way down into my tank. You can see a leg right next to my finger in the picture)

It ran fine after changing it out
I was leaving to go on a fishing trip the next day, so I decided to run a jumper wire to my fuel pump and run all my fuel through my pre-pump filter into some clean fuel cans before putting it back in my tank. After pumping all the fuel I could out, I ran a line down into my tank and siphoned out all I could into a bucket. The bottom of the bucket had some more large particles:
View attachment 98609
The new filter still looked clean after pumping my tank through it.

My fuel pump sounded weak while pumping out my tank and I'm fairly certain it's never been changed, so I decided to replace it with a new one before leaving just to be sure.

After I left the next day, I made it about 100 miles before it happened again. While waiting two hours for a tow I checked my fuel filter and it still looked pretty clean. I also pulled the DTC's and found P1211. I pulled the connector off my IPC and it had oil on it. Also checked my oil and it was right beneath the add mark on the dipstick.

The next day I was able to find a local mechanic to take it to because I was tired of screwing with it. They replaced the ICP in under an hour and I was able to fish that evening.

Truck ran great the 20 miles there and back, but it happened again about a mile from the room. I took the truck back their again the following afternoon and he checked the DTC's and the only code that showed up was P0605. They swapped out the PCM and IDM with used ones they had in their shop for testing.

Trip was pretty much over by then, but truck ran great all around town and I had my hopes up that it was fixed. Started the trip home and made it about 30 miles before it happened again. Called roadside assist and had it towed the 130 miles home.

Didn't really get a chance to look at it until today. and here's what I've done so far:

  • I checked all the fittings on my HPOP and none of them seem to be leaking oil.
  • Checked my fuel bowl/filter to see if I had any oil leaking in there and could find no evidence of any oil backing up in there (filter wasn't black and no o-ring parts).
  • Gave my IPR the once over to make sure it wasn't anything obvious:
    • The nut on the back was still there and was still tight.
    • Couldn't find any chafed wires on the IPR pigtail
    • I unplugged the connector from the IPR noticed that the plug attached to the body of the IPR was loose. Don't know this is actually means anything
  • I hooked up FORSCAN and monitored my IPR % Duty Cycle, IPC Voltage, and IPC PSI. The readings all appeared to be normal (All tests were done in neutral, plan running the same tests again while driving around tomorrow):
    • Idling, 770-780 RPM's for 15 seconds:
      • IPR % duty cycle between 10.6% and 11%
      • IPC PSI between 480 PSI and 500 PSI
      • IPC Voltage betwen .78V and .82V
    • 2250-2350 RPM's for 180 Seconds:
      • IPR % duty cycle ranged between 20% and 21.3%
      • IPC PSI ranged between 1160 PSI and 1175 PSI
      • IPC Voltage ranged between 1.58V and 1.68V
  • Injector buzz test completed succesfully, and all buzzes sounded pretty much the same.
  • Checked fuel filter and it appears fairly dirty with few larger particles:
View attachment 98593

  • I ordered the adapter needed to hook up a fuel pressure gauge to the fuel bowl from DieselOrings and plan on testing fuel pressure as soon as they come in.
Other Relevant Info:
In regards to dirty tank/fuel causing a restriction in fuel, I dropped my tank earlier this year when doing the hutch mod and wiped out the inside with shop rags until they started coming out clean.

At that time, I also discovered that my fuel pickup foot/screen had come apart. Instead of ordering a new one, I just bent the bottom of the new pickup tube at a 90 so it was parallel to the bottom of my tank and cut the end at an angle to increase the surface area of the opening. There is no screen across the opening to prevent large particles from getting sucked up.

Possibly Relevant Information:
This truck sat in my driveway from 2012 until the start of this year without being started. It ran great when I parked it and started right up after new batteries and new fuel. All driving up until August has been in my neighborhood due to needing new tires before it could pass inspection.


  • I know the first picture of the fuel filter isn't normal, but is it normal to have stuff like that at the bottom of your filter after less than 100 miles?
  • Is there anything else I should be doing/looking at other than monitoring ICP/IPR readings and Fuel Pressure while trying to recreate the conditions that caused the problem?
  • If it turns out not to be a fuel problem and there are no visible oil leaks, where should I go from there?
  • I'm not much of a mechanic, more of a part changer. So, any advice you could give would be greatly appreciated.


· Premium Member
15,558 Posts
I think you're on the right track with the fuel pressure. Are you planning on running the gauge such that you can see it when the problem occurs. I think you'll find you have normal fuel pressure when the truck is idling in your driveway and that it drops when the issue occurs. You might be sucking up something that's blocking your intake in the tank that drops away when the truck is off. When your fuel pressure is below normal, the PCM commands a higher ICP pressure which can throw the P1211 code.

· Registered
12 Posts
Discussion Starter · #3 ·
Are you planning on running the gauge such that you can see it when the problem occurs.
Yes, I plan on getting a long enough hose to reach up behind the hood.

All the material I've read regarding testing fuel pressure as well as IPR/ICP data states that you should test them under WOT. Unfortunately, I can't really find anything that tells me how to determine if my throttle is wide open. While driving, I assume the only way to judge this is by looking at RPM's. If this is correct, can anyone give me an approximate RPM range when I will be at WOT? Sorry if this is a stupid question.


· Premium Member
15,558 Posts
Well - I've never really thought about it - WOT just means you've got the pedal against the carpet. There's not really a throttle on these trucks per se. Its fly by wire so at "WOT" you're just sending maximum output from the throttle position sensor.

The more important aspect is you're trying to test the engine under load. That would imply hooking a trailer and towing uphill. Since that's not feasible, just flooring it when you're going about 45 MPH will put a reasonable load on the engine. You're trying to push it hard enough that something that only rears its ugly head when the engine is really working will show up. Like fuel pressure - might be fine at idle, but when you're really burning a lot of fuel, the pressure might plummet.

· Registered
12 Posts
Discussion Starter · #5 ·
Just wanted to post an update on my situation.

After my parts came in from DieselOrings, I got everything rigged up and proceeded to drive around my neighborhood while monitoring fuel pressure and live ICP/IPR data.

Fuel pressure was around 60-65 PSI and 50-55 PSI while cruising. I found that the fuel pressure would consistently fall into the 20-25 PSI range while flooring it in second gear and climbing a steep hill. If stayed on level ground immediately after that it would quickly rebound back to 50-55 PSI. If I went up another hill right after that it would drop even further and take even longer to rebound back to cruising level.

ICP/IPR data appeared normal going off the numbers given here

Not really wanting to have to drop the fuel tank again, I decided to rebuild my FPR. This had no effect, so I was forced to drain 20+ gallons of fuel and drop the tank.

After I got everything down, the problem revealed itself immediately after I blew air up the pickup tube:
Pipe Auto part Metal

All of this headache due to the fact that I failed to check my compression fitting under vacuum before reinstalling the tank.

Got everything back together and it feels/sounds like a totally different truck. It is noticeably quieter inside the cab. I drove around town for about an hour today and fuel pressure pretty much sticks between 67-70 PSI while cruising and drops about 3-5 PSI under hard acceleration.

I am concerned that the lack of fuel pressure may have damaged my injectors. When I'm accelerating and change gears my truck kind of stutters between 1500-1800 RPM's. Once I get above 1800, all is good. I was hoping it was just residual air in the system, but it didn't seem to get any better after driving 30+ miles today. I don't know if I'm up for another battle so soon after this one, so hopefully it clears up on its own.

· Registered
628 Posts
Get some lube to those injectors. Put some Lucas in your tank for at least the next few tanks.
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