Well, my truck missed for the 1st time yesterday. I have noticed a slight loss of power over the past month or so, and less smoke. I don't have a pyro or boost gauge yet since my truck is not really turned up much at all. I was pulling onto my road, and was shifting from 2nd to 3rd, and it missed. I mean sounded like it had died for a split second, and then run smooth as glass like always. I do live on a dirt road that is kinda bumpy, so I suspected maybe the clip to the shut-down had gotten loose, so I wiggled it when I got home and it seemed tight with no corrosion.

When I 1st noticed a loss of power, I immediately ordered the parts for a fuel pressure gauge. Got the banjo bolt from Geno's, the correct snubber (Thanks Wannadiesel) and the gauge on order. Still waiting on the gauge, so when I get it (Hopefully today according to tracking) I will see if I have a lift pump going south.

I also have a few other questions:

1. Will a lift pump going out cause your truck to run rough or any other symptons than loss of power? The truck idles/runs really smooth.

2. I understand my fuel pressure should be around 7 PSI at idle, and no lower than 2 to 3 PSI at WOT - just wanting to confirm this should be my baseline.

3. What else should I look for in a truck that has my symptoms described above?

I meant to try and crank it this morning before I left for work (rode with my wife today). I seem to recall while searching the forum earlier in the week that if a lift pump is going out, it would just not crank eventually.

Sorry for the long post. I will be off tomorrow and away from my PC 'till Monday, so I wanted to give all the info I could so I might have a better battleplan while trying to troubleshoot this weekend.

Thanks!

 

When my lift pump went out, it did not miss at all. All it did was fall flat on it's face when I put the pedal to the floor. And I drove it like that for 250 miles. The only thing that I can think of that would cause such a miss is the shut down solenoid. Maybe check the whole wire and not just the connection.

 

How old is the fuel fitler? If it did it right before a shift, it could be either filter or the LP.

DP

 

Good question I should have included into my original post. Since the entry of ULSD in my area, my 1st thought was a clogged fuel filter. It was my understanding the ULSD would "clean" the tank and make for alot of trash getting into the lines. I have since changed the Filter twice in the last two months thinking I was getting years of trash out of my tank from the new fuel. The current filter is two weeks old.

 

Replace the push terminal with a ring terminal to eliminate that as a possibility. Then see if it does it again.

 

Hoooked up my fuel pressure gauge and I'm running 2.5 psi at idle and it pulls down to less than 1 psi at 65 mph. Is this standard for the diaphram pump?

 

That is very substandard. Get a new lift pump. I had a Delphi unit from usdieselparts.com (under $40 with shipping) that made 8 psi at idle.

 

Digging this one up from a week and a half ago to thank everyone for their direction on my problems. 1st thing I did was replace those clips with good ring terminals to aleviate that from the equation as well as checking my wires, which appear to still be in good shape.

Next came my p-lift pump. Thanks to the sticky write-up, this install took less than an hour. The hardest part was trimming the insulation, and that was just because its an akward place to whittle with a razor knife. My fuel pressure is now happily at 10 psi at idle, and only pulls down to around 4 psi and WOT. I must say the new lift pump woke my sluggish old ride up. If anyone is having a decline in power, get a fuel pressure gauge to make sure this is not your problem. Here are the parts I used for my fuel pressure gauge:

1 - Geno's tapped Banjo Bolt
1 - Snubber # 4034K64 from McMasters-Carr (Thanks Wannadiesel)
1 - 1/8 NPT needle valve from the local Hydrolic shop
1 - Oil pressure gauge plumbing kit from the "HELP!" Section of any autoparts store
1 - 16 psi fuel pressure gauge from surpluscenter.com
1 - 2 & 1/16" gauge mount

I have the gauge mounted on the side of my break controller mount. My loss of power was nothing drastic, but over the period of a few months. Again, thanks to everyone who helped me out.