Help with fuel system diagnostics

[PLohr]

Guys,

Good idea. I plan to remove the tank / bed or have it removed to have the fuel filtered and the tank cleaned.

I removed the pre-lift pump fuel filter. It was very difficult to blow through. Definitely restricted. I drained and kept what was in it for inspection. There was one 1/4" drop of water and very fine sediment particles. I cut the filter open and more fine sediment (not adding up to much). I don't think either of these are the cause of it being severely restricted.

This is not a screen-type fuel filter as mentioned by BigPapa. It has a paper element. Do you think the diesel fuel might be incompatible with this paper element, and perhaps the fuel plugged the paper element? This filter was on the truck for a short time - 7 months and probably only a few thousand miles.

Contents of filter housing:




Scraped the inside of the filter housing:

 

[cerberusiam]

A small paper element on the suction side of a diesel pump is not the best idea as you have seen. A large paper element of the push side will not have anywhere near the problems noted.

Considering what we know now you should move to an in-tank pump with multi-pass filtration for best efficiency. A 10 um WS to 5 um WS to 3 um solids filtration is about as good as filtration gets and likely will not plug even if you get bad fuel. Even a stock in-tank LP will push thru that filtration adequately for stock fuel requirements. Truck won't run right if fuel is really bad but it should get run.

Your best solution is where you fuel up and keeping those fill ups to 1/2 tank or so if your luck runs out. Water separation is the only way to fix excess water in the fuel, when the WS plugs you change it and keep going given the filters are downstream of the pump. You can treat the fuel with additives to help the pump and contamination easier with an in-tank pump.

Unless the fuel is just sludge even moderately solids contaminated fuel won't stop the truck in its tracks with multi-pass filtration and large filters. The stock cannister will keep a lot out of the fuel system so you just have to deal with floating fines, that can mitigated by limiting fill amounts.

Unless you are sure the plugged filter cam from fuel on the trip, I would change home filling sources as a first step.

 

[PLohr]

Thank you for thinking this through, cerberusiam.

Good thoughts. I especially like the three filter idea.

 

[capt fast]

Hello, guys.

I almost posted this in the 911 section. We are about 6 hours from home. But the truck is running, although not very well.

We topped off (8 gallons) with diesel fuel near Pinehurst, GA then the truck lost power. Wouldn’t exceed 60 MPH. Stopped at a rest stop to check things out. Took a 1/2 cup fuel sample from the filter housing drain to check for water with the engine still running. The diesel proceeded very slowly out of the valve. Eventually the injectors started sounding very erratic then the truck died while I had the drain valve open. I didn’t think opening the drain valve caused it to die but maybe that’s possible. After the engine quit, I primed the filter housing by cycling the key. It didn’t restart right away but eventually it did restart. Anyways, more of the concern is the loss of power.

The low pressure electric pump is working. I checked that.

Does the CP3 pump fail in this manner? It’s not totally dead yet.

Is it possible to get water in the fuel and never see the light come on?

2003 3500 2wd manual transmission. 180,000 miles.

Thank you for any help,
Paul Lohr

first thing always is renew fuel filter. feed pump pressure and timed flow check. sock in fuel tank. wif valve is before filter media in the housing. cp3 feed is inside filter on a standpipe that prevents picking up strange stuff that make it thru the filter. feed pumps have a finite life time. renew it on general principals. just as much hassle to check it out as renew it. pu tube sock in the fuel tank is something to check when empty, if there is one. damage to feed lines betwixt tank and feed pump sucking air. consider better filtration of some sort.

 

[capt fast]

A small paper element on the suction side of a diesel pump is not the best idea as you have seen. A large paper element of the push side will not have anywhere near the problems noted.

Considering what we know now you should move to an in-tank pump with multi-pass filtration for best efficiency. A 10 um WS to 5 um WS to 3 um solids filtration is about as good as filtration gets and likely will not plug even if you get bad fuel. Even a stock in-tank LP will push thru that filtration adequately for stock fuel requirements. Truck won't run right if fuel is really bad but it should get run.

Your best solution is where you fuel up and keeping those fill ups to 1/2 tank or so if your luck runs out. Water separation is the only way to fix excess water in the fuel, when the WS plugs you change it and keep going given the filters are downstream of the pump. You can treat the fuel with additives to help the pump and contamination easier with an in-tank pump.

Unless the fuel is just sludge even moderately solids contaminated fuel won't stop the truck in its tracks with multi-pass filtration and large filters. The stock cannister will keep a lot out of the fuel system so you just have to deal with floating fines, that can mitigated by limiting fill amounts.

Unless you are sure the plugged filter cam from fuel on the trip, I would change home filling sources as a first step.

been having good results with a cat filter ~3 micron filtration. makes the cp3 a happy puppy.

 

[slowmover]

Exactly, id be surprised if it was still filter mounted at 180K miles.

(Cough, cough). Well, I’ve replaced mine once. At about 175k as I recall. Better had to get in line behind other priorities.

Good advice above on how to deal with potential problems posed.

.