[scoutcamper]

Hey everyone,

My parents are using the truck today to move my brother to school in Klamath Falls, they got most of the way there, went to pass someone on a hill, and at WOT the truck would not pass 60mph and "Started Running Rough". They got to the top of the grade(6 or 7%, not huge) and the truck smoothed out and went back to doing 75 no problem.

I did send them with an elm327, got them to pull codes and it had a p1209 stored. Had them pull hydra, and they are currently back on the road, with gauges up on the phone for HPOP and Duty cycle. They will be monitoring them if it exhibits the same symptoms, right now at around 75mph(foot control not on cruise) they have seen HPOP as low as 721 and as high as 1470psi, hovering around 950psi, and right at 25% IPR.

What am I looking at for a cause here? Had Dad check the ICP, no oil on the connector, have recently done the fuel bowl pressure regulator that is on the return line, and the hutch mod. Also the mechanic did a Napa HPOP about 3 months ago.

 

[RT]

It could be the HPOP is a bad unit. It could be an IPR issue, or it could be a biased ICP. Since your dad can watch the ICP and IPR duty cycle, I would have him do the Swamps HPOP test. Here's a link - https://swampsdiesel.com/files/hpop.pdf

This assumes the ICP is reporting accurately - the only real way to verify this is to plumb a mechanical gauge and compare the readings.

 

[scoutcamper]

Just had him do the swamps HPOP test, it leveled off at 2600psi, so for a napa pump its actually pretty good, assuming the ICP is good.

Is it possible that this is a fuel issue? That is what I am leaning towards because we have been fighting fuel issues off and on for months on this truck now. Did the hutch mod, the fuel bowl pressure regulator and the IPR, and have replaced all fuel filters(this was all at the 217,000 mile maintenance . Only things left in the fuel system that are not new are the check valves, fuel pump, and fuel lines.

 

[RT]

Low fuel pressure requires higher IC pressure, so that is definitely a possibility. I believe we should ALL be running a fuel pressure gauge.

 

[scoutcamper]

I think i will be ordering a fuel pressure gauge tonight. For now with no chip the truck is running OK, still acts like its starving for fuel at WOT, so they are going to drive it home carefully, and hope they make it.

I am suspicious that the factory fuel pump may be on its last legs(it has 222,000 miles on it) but I plan on confirming that before I replace it.

Is there a reason to buy the bosch/ford oem over the napa fuel pump? I know on some things brand really matters(see also CPS), but I don't know if fuel pump is one of those things.

 

[scoutcamper]

Alright, they have the truck at home now.
Apparently it ran trouble free the whole way home(almost all downhill).

Thought: We have been fighting the same issue for months now, it all started with the truck bogging and missing pulling our boat home from the lake in june, but only when the motor was under load, driving around town it ran fine, mechanic swore it was the IPR, replaced it, and injector #8 went out, so we replaced all 8 injectors with brand new ford ones, issue still existed, mechanic did the hutch mod for us(i observed him do it, it was done right), issue appeared to go away, however we have noticed that on the first and only first startup of the morning, for about 15-30 seconds the truck has a miss and smokes white, then it cleans up and works fine rest of day(not cold, 80F at night here).

The truck pulled our 12,500lb travel trailer to the coast(between redding and the coast is 4 8% or greater, longer than 2 mile hills) without any issues other than the white smoke and miss on first start.

Now it did this. Is it possible that this is all related in the fuel pump? It seems really unlikely that the truck would be fixed, then not, then fixed and pull the heavy trailer, then break again. If it is related, the only thing i can come up with is the fuel pump.

Does this make sense to anyone else? Is it possible my white smoke+miss is related to fuel pump somehow? If not, I am open to suggestions as to what it could be, did a new HPOP, it tested good, settles at 2500PSI on a WOT run.

 

[scoutcamper]

UPDATE: Just drove the truck with my datalogger on it, when it starves for fuel IPR hist 62% and HPOP is at 2500psi. What does that mean? I know its not supposed to clear 50% Basically when it happens, if you keep boost at 0 it luggs but it works, if the turbo spools at all it starves for fuel.

 

[scoutcamper]

More Detail now that I have a 2nd person in the truck. Leading up to when it starves for fuel the HPOP is hovering around 900PSI, and the IPR skyrockets to 62-63%, when it actually starts missing the IPR drops back to the 35% area and the HPOP skyrockets to 2500PSI.

 

[scoutcamper]

Truck just threw P1211 AND p1209, it is dropped at the mechanic who is going to do diagnosis only, will see what he thinks, his initial thoughts after a quick test drive with me in the truck is that it is the oil strainer on the HPOP pickup tube inside the timing cover is plugged and that the HPOP is starving for oil, based on the fact that everything else is new.

Tomorrow he is going to put a real fuel pressure gauge and a real HPOP gauge on it so he can see in real time what is happening.

 

[scoutcamper]

Question: What would happen to ICP and IPR if suddenly fuel pressure went to zero? Would they spike? Fall? both? Something entirely different?

 

[RT]

They would spike in an effort to maintain fuel delivery.

 

[scoutcamper]

Update: Talked to the mechanic this morning, apparently he had some free time on Saturday so he went down the the shop, threw a fuel pressure gauge on the truck and road tested, at idle you see roughly 45 psi, at 65mph you see 10psi. He changed the fuel pump, and now you never see below 45psi, he is going to do some more road testing today, and then pending no other issues surface, on Thursday I will go get the 12,500lb toy hauler and haul it up the biggest mountain within an hour of me, roughly 8% grade for 5 miles with lots of narrow switch backs(299->Burney for those familiar with the redding area) and will hope that it is fixed, but will have backup truck on standby in case its not fixed.

 

[scoutcamper]

Also: Here is a video my parents shot of the OBD Gauges as the truck started doing its thing, finally had time to post it. At one point(not on camera) they got it to shake so bad that it threw the phone off the dashboard, but this is what it was doing: https://www.youtube.com/watch?v=ahpojT-cm4k

 

[RT]

Fuel pressure is much better - BUT 62 psi is stock. Some guys run stiffer springs in the regulator to knock that up to 70psi. 45 is still in the area where you could damage injectors.

I'd start with rebuilding your fuel pressure regulator - especially since its not moving down at throttle. If that doesn't get you to normal, then you need to drop the tank and clean those screens or do the Hutch mod.

Rebuild Kit for the 1999-2003 Fuel Bowl Pressure Relief Valve

Welcome to guzzle's In-tank Hutch Mod Web Page

 

[blue99stroker]

If I remember he just rebuilt the fpr and got rid of the screens.

Diesel Orings carries a billet fpr housing with stiffer springs. And it's only like 40 bucks

 

[scoutcamper]

Talked to mechanic again, he is going to do some more strenuous road testing but is ready to give it back. He changed all the filters(inline pre-pump from hutch mod and the bowl filter), pressure came right up to 62 @ idle and 56-62 @ WOT from 65mph-80mph. Sounds like the inline pre-pump was apparently pretty clogged, have put 5K miles on it since the hutch mod, will be keeping a much closer eye on it from now on(also, no more buying the cheapest diesel in town, I worked for a fuel jobber for 3 years, I know better now ).

blue99stroker is correct, i need to update my signature but i did the hutch mod and the FPR about month ago.

 

[scoutcamper]

Got the truck back last night, it road tested great! Will be towing heavy with it on Saturday, but for now I am optimistic, it starts easier than it has in years and runs smoother than I ever remember it running. I may drop the tank in a few weeks when I have some time and really clean it out, but for now its running, I have spare fuel filters in the truck ready to change out if needed.

 

[blue99stroker]

that's great it was an easy fix.

ya it only takes one bad tank of fuel to do some damage.