What do I do now???????

[Woodturner Nate]

Fuel pressure issue. Can't maintain pressure when going up a hill, long accels, etc.


-cleaned inlet screen and steel wool-type filter on pressure regulator
-replaced fuel pump
-replaced fuel filter
-replaced cam position sensor
-replaced leaky fuel tank

On short test drive, acted like it needed to be primed--I didn't bleed the line after cleaning FPR screen and FPR filter. Bled line, then eventually started and ran okay, but fuel filter light is on, indicating low fuel pressure. I don't have a fuel pressure gauge.

After bleeding the line, once it was idling right again, I pushed the schrader valve, and nothing came out; like it was equalized pressure or something. I just cleaned the whole thing out; no reason for it to get stuck or clogged now.

I don't know where to go from here. Is there a rebuild kit for the fuel pressure regulator? All the o-rings are kinda hard and the diesel green colored. Could it be sucking air in through one of the rings?

[jesilvas]

How much in the tank being used? And have you checked the pickup assembly in tank?

[Woodturner Nate]

It's on the rear tank now, which is half full. I just replaced the rear tank, and replaced the intake strainer at the same time. As far as I know, its sound otherwise.

[jesilvas]

Interesting.
I guess you could just use new o rings and replace the fpr, it can be worn out. I'd upgrade to the one from dieselorings.com.

I made my Samsung SGH-I997 send this.

[Woodturner Nate]

Just so I'm clear; do you mean replace the o-rings and replace the injector pressure regulator? There are so many acronyms that I'm confused. The o-rings I'm talking about are attached to the FPR attached to the fuel bowl. After reading a bunch of old threads, I'm now worried about the IPR injector pressure regulator attached to the high pressure oil pump. When it wouldn't start back up, the IPR relay was loose. I'm thinking that in all my wrench turning I've loosened the crimp-nut thingy on the IPR.


There is a kit for the IPR valve o-rings. If they were bad, wouldn't I have an oil leak? I mean there is a bit of oil on the HPOP reservoir seal, but it's been there since I bought the truck, and it does have nearly 400K after all. All the problems started happening within a couple days of replacing the glow plugs and glow plug relay. Side-note it starts fine when its cold now though. I'm just thinking maybe I loosened something or knocked something loose. I've checked and re-checked but I didn't really check to see if the nut on the IPR has any play at all. I'm going to get some electrical parts cleaner and clean every harness while I'm searching for a possible air-leak into the fuel lines.

[Patrick Feeley]

Generally if the IPR o-rings are bad, it won't start when hot/warm (and sometimes not at all. You should be able to snug the IPT "tin nut" down so the coil doesn't move around. For the fuel pressure, check to make sure that the Fuel Pressure Regualtor (FPR, driver's side of the fuel bowl) spring is not kinked or broken and that the plunger and it's bore are not scored causing it to hang open. Cheers!

[Woodturner Nate]

Thanks much Patrick!! Definitely no scoring on the bore of the FPR. Now that the mention of hard hot starts, I think the IPR is going or at least intermittently having problems. There have definitely been times when I've just shut it off, gone inside somewhere and come right back, and it has to crank a while before it will start.


I had a diagnostic done and all 8 injectors passed the buzz and cylinder contribution test, the only code was the cam position sensor, which the mechanic said must have been an old code, because it read "no activity" which he said would have meant a no-start situation. The cam position sensor I replaced didn't look original, but the plastic was brittle. Anyhow, I ordered a complete set of o-rings from dieselorings.com as well as banjo washers etc. New IPR, IPC, schrader and fuel restriction sensors also ordered. What I don't need I can send back, but GD this thing is gonna get fixed by this weekend.

[Woodturner Nate]

Well, all parts in. The IPR valve was really easy compared to how a bunch of threads seemed to describe it. Since I had the fuel bowl out to replace all the o-rings, there was plenty of access to clean the V. I put down the dirty paper towels underneath the IPR valve before loosening it, then hand-loosened the valve with the new one ready in my other hand. I probably only lost a few teaspoonfuls of oil, tops. The old solenoid was very loose, and the connector full of grease. Since I had already purchased a new IPR valve, I installed it, but it might've been just fine with just a cleaning, o-ring replacement, and tightening. The IPC sensor, on the other hand, was full of oil in the harness. I don't know how it got in there, as it wouldn't happen normally with oil seepage out of gaskets and such. If it was leaking, and not communicating correctly that might explain some of the symptoms?


I haven't actually been able to start it yet--doing some rehabbing of the lights at the same time, and I need the batteries out. Will post later with updates.

[Fordman247365]

Yes, if the ICP had oil in it, it's shot

[Woodturner Nate]

Well, today was not the best day. I got everything back together, looking pretty good, a hell of a lot better than it was before the problems started; cleaner, shinier, new parts, etc.


I tightened up the loose trim pieces around the headlights that had been really bothering me since I bought the truck, but broke one of the mounting pieces in the process. No sweat; probably $25 on Amazon, but on principle, I was pissed.


I put the batteries back in, and turn the key to the start position, and hear a bunch of clicking from near the power distribution box ( and the IDM). I start freaking out, and checking to make sure that I didn't do anything wrong, or hook anything up wrong. I get out the multimeter, start checking things, then notice that I put the batteries in on the opposite sides and decide to swap them just in case one was going dead or something. Long story short, I hooked up one in reverse. Glad I didn't blow anything up.

Switched the terminals, and things seemed fine. The clicking stopped, and more importantly, the truck started and seemed great. I let it warm up, it seemed fine, I went on a short test drive, and the fuel filter restriction light came on, but it seemed to have no issues, so I figured it was air trapped in the system. The light went off after I bled the line a bit. On a longer test drive, it seemed to do great. The light came back on, but no problems at first. I was really pushing it, trying to make sure the pump was keeping up with the demand, but driving on a dirt backroad. The road got really bumpy, and trouble started. After a little ways, it lost all power and stalled out. I immediately thought it was the IPR harness, which came off all too easily when doing the replacement. I pulled it, and found that one of the connectors was totally loose in the harness. Like a dumba$$, I went on my "short" testdrive with only a few tools. My needlenose pliers ended up stuck under the fuel bowl until a teenager whose house I stalled out in front of came out and lent me a pair. Got my pliers back, and the IPR harness reattached.

It'll have to be replaced. I'm ordering the pigtail harness, but I can't wait for it to get here. I might have to remove the solenoid and solder the wires right to it temporarily til the new harness comes. Once I got home, it must've been getting a weak connection, because when I revved it, it blew lots of white smoke, and wouldn't rev past 2500. On the start of the test drive, it would rev beyond 3000 no problem.



I'm hoping my luck with this truck gets better, because I'm about fed up.