Inconsistent fuel delivery

[tsmall07]

**Update at the bottom**

So I finally got this thing running again after about a year. I had to replace the fuel pump and had other things going on and was gone for the whole summer so I didn't get it done. I wired in an electric pump to replace the mechanical one a few days ago. The truck ran fine before I let it sit for a year.

I got it inspected and took it on its first decent trip since I got it running (90 miles round trip). The truck seems to surge and drop off as I drive. It's not enough to really change my speed, but enough to be noticeable. Twice after a stop, it acted like it was going to shut off (no throttle response) and once it did shut off as I was coming up to a stop. It started right back up again after the shutdown. I bought a new main fuel filter, but I don't really know how to do it. Is there any way to drain the filter before you pop it off? I tried unscrewing the thing on the top, but all the fuel just ran out the drain to the side of it.

Could this problem have anything to do with the trans? The shifter lever is very inaccurate and it is hard to get it in the right position.

What could happen to the truck while it's sitting to make it behave like this? (please don't say I need a new IP... )

Edit: M1008, btw. Don't kn ow if it matters.

 

[mangus580]

Are you sure the electric fuel pump you put in has enough flow??

 

[mutt1966]

what would be the flow rate for a electric pump. thanks Scott

 

[tsmall07]

I think it should. I got the pump for a later model 3500 with the 6.5

 

[tsmall07]

I did also put in a rather cheap in line fuel filter before the pump. I guess that could limit the flow, but it has 5/16 inlet and outlet.

 

[hogtruck]

Should be a drain on the bottom of filter base, pax side (-10, p3-7, -20, para 3-17). After new filter installation, be sure to bleed filter as per the TM.

 

[mangus580]

I did also put in a rather cheap in line fuel filter before the pump. I guess that could limit the flow, but it has 5/16 inlet and outlet.

That might do it!

Cheapie inline fuel filters arent really well suited for diesels. Keep in mind, the system flows alot more fuel than the engine uses, and returns it back to the tank.

 

[tsmall07]

So what should I look for in an in-line filter to be sure I get the right thing? I definitely don't want to run without a filter at all.

Also, how could it surge if the fuel is limited? Seems as though it would only lag.

 

[tsmall07]

I'd say I found the problem! The filter sock in the tank is completely clogged. I'm surprised it would let enough fuel through to even let it idle (that's all the truck would do by the time I parked it. I guess that's algae that has clogged it.

Anyone know where I can get a new sock filter? Neither the local parts house nor Chevy say they can get it.

 

[hovenga67]

I had the same problem. I just ripped it off and I run a cheap clear fuel filter before my elecric pump. It has plugged up 3 times from the junk in the tank. But it is easy to replace. I'm glad I didn't put a new sock in because it would be plugged by now. I wouldn't put a new sock in without taking the tank out and cleaning it. I just slid my box back to get at mine. I went thru the same crap to figure this out I replace my injector pump and my lift pump for nothing. At least I had the injection pump laying around.
Brent

 

[CUCV85]

So what should I look for in an in-line filter to be sure I get the right thing? I definitely don't want to run without a filter at all.

Also, how could it surge if the fuel is limited? Seems as though it would only lag.

What do you mean by in-line? Don't use them!
Do you mean a Spin-On Fuel filter/Base Assembly?
Usually guys mount it right where the Stanadyne 80 filtration system was.
The "Box style Filter AC Delco TP1006"
Chevrolet Car Parts Surplus half way down the page!
Military Truck Filter 6.2

 

[tsmall07]

I'm glad I didn't put a new sock in because it would be plugged by now. I wouldn't put a new sock in without taking the tank out and cleaning it.

I was thinking about not putting another one in. Glad to hear it worked for you. I'm taking the tank tomorrow to have it cleaned.

That really sucks about your IP though.

What do you mean by in-line? Don't use them!
Do you mean a Spin-On Fuel filter/Base Assembly?
Usually guys mount it right where the Stanadyne 80 filtration system was.
The "Box style Filter AC Delco TP1006"
Chevrolet Car Parts Surplus half way down the page!
Military Truck Filter 6.2

I just put a filter in line to save the electric fuel pump I put in. I still have the stock filter box under the hood.

 

[tsmall07]

Somebody told me it is more likely asphaltene instead of algae.

I dunno. Whatever it is, it's going away.

Link:

Diesel Fuel Facts

 

[hovenga67]

I also still use the factory fuel filter off a 83 half ton diesel.