New fuel pump, still low pressure

[bigfords]

Heres the quick story...I must be missing something.
I installed a Fuel pressure gauge on my truck 2 Thursdays ago. Drove my truck home from work (about 8 miles), then back to work again in the morning with no problems. On my way home Friday night, started up a hill towards home and fuel pressure started to drop until truck would hardly run. Babied it home (after having to prime the fuel system several times with KOEO) Figured I needed a fuel pump so I ordered a Bosch from Strictly.

I just got the fuel pump in and I still have the same problem! Only builds 20-25 psi and truck will fire but then die. Fuel tank is about 1/4 full.

The guage that I installed is an ISSPRO EV2, and put the sender in the lower port on the rear of the stock fuel bowl (until I get an RR fuel system).

What is my problem? Tank restriction? That first Thursday driving was fine, truck was holding 60 psi or so until I would get about 3/4 -full throttle.

Everything mostly stock except for 238/100s. Just hope I didn't hurt the injectors with the low fuel pressure.

 

[Strictly Diesel]

Put more fuel in and see if the problem goes away. If it does, 10 to 1 the pickup strainer foot at the bottom of the sending unit is broken off.

If that doesn't change anything, could be a problem with the stock fuel pressure regulator, could be a restriction between the tank and the pump (kinked hose, plugged screen or filter, etc).

All of this is assuming no external, obvious, fuel leaks.

 

[lariat 7.3]

pick up foot snaps off and run out at a 1/4

 

[bigfords]

Thanks Dennis! I'm going to run out and get some fuel right now. Funny thing I got the pre-pump kit with the Bosch pump, I just need to get it to the shop to put it in and I'm stuck at home. I'll try adding fuel first.

 

[ghohouston]

If adding fuel doesnt help, your sending units fuel strainers are probably clogged to hell. Ive seen it on countless 7.3's with higher mileage

 

[TyCorr]

If adding fuel doesnt help, your sending units fuel strainers are probably clogged to hell. Ive seen it on countless 7.3's with higher mileage

Its funny, I was a little worried, last winter I did all my tank mods. The previous winter I had an issue with the fuel bowl and removed it to rebuild it. There was dirt in it. Ok. Whatever. Then I had to use drillbits to get through it near the drain. I had to chip it out with a flatbar. I kept recalling that when I prepared to mod the tank pickup, draw straw, and vent lines. I pulled the pickup foot and mixing valve and was afraid to look at the foot. Buuuut there was grass on it! :shrug: not enought to plug it. It was still.green too. Weird. So i went straight to the bottom of the tank. Nothing. Clean. Nobody was more.shocked than me.

262k miles and the tank is clean.

 

[ghohouston]

Weird. I think the reason most of them ive seen so clogged, are from filling up from fuel trucks out in windy, extremely dusty conditions, and god only knows what else gets in there

 

[bigfords]

Good news...just added a few gallons of fuel and the pressure built right up to 63 psi or so! The truck has been sitting in my driveway for a week and a half and all I needed to do is add fuel. haha I'm glad for an easy fix, and now I've got 2 SD pumps for my dual setup in the future.

What are the odds that I put a fuel pressure gauge in my truck, and the next day this happens? oh well...

Now I just need to keep the tank half way full until I get the pre-pump kit in.

thanks again guys.

 

[CSIPSD]

My screens in the tank got so plugged up that I could not hold 20psi!!!

http://www.youtube.com/watch?v=lqy1138spFw

 

[TyCorr]

To the OP- gonna put a sump in?

 

[Powerstroke Man 6.4]

Weird. I think the reason most of them ive seen so clogged, are from filling up from fuel trucks out in windy, extremely dusty conditions, and god only knows what else gets in there

I pulled the tank because I installed my Beans diesel sump last month and put the walbro in and I thought it was clogged causing low fuel pressure. opened the tank pulled the sending unit guess what tank clean no algae, dirt anything. Pulled the filters was little dirty not bad pickup was intact everything was fine.. I was surprised 309,000 miles and the tank sparkling clean LOL.

 

[bigfords]

Nah, just going with 3/8 pick-up. I actually just got the pre-pump kit from Strictly today, hopefully I'll get that put in within a week or so. I'm not planning on pushing much more than 500 HP, so I think that will suffice.

CSIPSD, was that with the stock pick-up? Did it damage your injectors?

 

[Powerstroke Man 6.4]

Nah, just going with 3/8 pick-up. I actually just got the pre-pump kit from Strictly today, hopefully I'll get that put in within a week or so. I'm not planning on pushing much more than 500 HP, so I think that will suffice.

CSIPSD, was that with the stock pick-up? Did it damage your injectors?

I was running 20 PSI for a while IDK if it damaged my new singles that I put in but... It ran like sh** though lope at idle no power. Finally found out that it was a tired pump new walbro now its all good.

 

[CSIPSD]

Nah, just going with 3/8 pick-up. I actually just got the pre-pump kit from Strictly today, hopefully I'll get that put in within a week or so. I'm not planning on pushing much more than 500 HP, so I think that will suffice.

CSIPSD, was that with the stock pick-up? Did it damage your injectors?

More then likely it did... but who knows. They went another 40k before I blew the motor and had them rebuilt at P.I.S...

I was running 20 PSI for a while IDK if it damaged my new singles that I put in but... It ran like sh** though lope at idle no power. Finally found out that it was a tired pump new walbro now its all good.

Be careful with that Walbro, infact I would go ahead and order a quality Bosch pump right now to have on standby...

http://www.riffraffdiesel.com/mm5/m...de=GZ-21-006&Category_Code=F731-FS-FUEL-BOSCH

The Walbro is not rated for diesel... It will fail, its only a matter of time.