Installed Kennnedy's control harness and it works like a charm. Problem is this: Upon key up I have 6-7 psi, after a short drive the pressure drops to 0 and stays until key off, at which time the pump is still running and I regain pressure at 3-4 psi till oil pressure drops. The lift pump is new but I'm wondering if it just dosen't have enough ball$ to keep delivering at a reasonable rate (3-4 psi) while under load.
Also is there something in the fuel tank like a sending unit that could be clogged? I have a small amount of vacum when I take the fuel cap off. It is the correct Stant Diesel Cap (red with pressure release button) but should I gut the innards?
Ed

No it does not have the balls, need a HO lift pump IMO see http://www.dieselplace.com/forum/showthread.php?t=42291&highlight=feeding+the+beast

& http://www.dieselplace.com/forum/showthread.php?t=75397&highlight=feeding+the+beast

I have a HO pump stock replacement and still I pull it down to 0 psi momentariliy when I get on it (but my frame mount fuel filter may be the extra load the HO pump is working against for the momentary loss as well), so back to the parallel with Cummins idea, & yes there is a in tank sock as well which could also be a possibility.

So to change this sock - I've got to drop the tank and find a place that sells an aftermarket sock. I'd love to hear some suggestions/heads up before embarking on this next 6.5L adventure.
P.S. The Kennedy "Control Harness" is a great upgrade. Always on (when running) and the push button primer is pure genius. More on my install in a future post.

The sock is available at the dealer for less than $10, I think. Yes, you have to drop the tank and remove the float.

I would love to know what the best replacement lift pump would be for us 6.5 owners. I've heard a lot of opinions but I would especially like to know the specs of the various direct replacement Delphi pumps. The Walbro 6065 looks pretty good.

What do you guys think?

http://www.walbro.com/category.aspx?id=134

I think this is their new product line?

I installed a Carter P74143 direct replacement lift/supply pump on my rig. It sends fuel on key up at a rate of 6-7 psi. After running the engine on the road (regular driving 30-65 mph) it drops to 0 (zero) psi. After shutting down and restarting it delivers at a rate of 3psi parked but as soon as I throttle it up a bit it drops to 0 psi (zero) psi - upon release of throttle it climbs up to 1-1.5 psi, again this is in standing still in park.
I guess I'm gonna order Heath's high output direct replacement as per Turbine Docs suggestion. Should have in the first place - I could have saved $89.00 (the price of the Carter).:duh:
I'd like to add that this is not a bash of Carter or any other pump manufacturer - my truck's fuel system just seems to need more psi from the lift pump. In another truck they may work out just fine.
Ed

What do you guys think?

http://www.walbro.com/category.aspx?id=134

I think this is their new product line?

I did not see where it said if it would flow through on fail?

I was told they would CR but can't remember where.:o:

I did not see where it said if it would flow through on fail?


Beat me to it CR that was going to be my comment,

Kennedy's pump looks like a good solution hi volume & flow through on fail,
as is Heath's HO pump, Heath pump maintains as long as I'm not getting into it hard (really hard).

Kennedy or Heath would be the 2 I'd look at as they are ones known to work, Walbro mite be an option if price is rite and it continues to flow on fail.

My Cummins pump was acquired for free so that is the incentive to make that work, they are readily available for others to copy as a solution if I can fabricate the correct set up.

I got the Heath pump because it was a direct plug & go pump no other plumbing mods required and I needed one ASAP, again it will work for most it does deliver better than a stock pump but I'm pushing the envelope all the time in the quest for more power, so more is better for me.

Do you know what the specs are or what model Delphi the Heath unit is TD?

Afraid not, I'm getting 10 psi @ idle, run 3-5 psi at cruise, get on it mildly drop to 3-1 psi depending how hard I hit it, if I'm already "into it" and go some more, I get a momentary drop to 0 then back up to 1-2 psi until I achieve cruise speed I'm after, wherein it comes back up to my 3-5psi range. The gauge I have plumbed in was/is an el cheapo so range of accuracy is unknown, I attempted to calibrate it to a 0-15 vac/press test gauge I have so it's sort of accurate, or it at least runs with the other gauge I have.

I'm using it more as an indication for pressure that the lift pump is delivering fuel period, someday I'll have an instrument quality gauge on it.

just a comment on the cummins lift pumps. I did a google search on them the other day. The lift pumps on the 98.5-2002 (I'm pretty sure they stopped using it in 2002) was prone to failure. The worst I read about was one guy having to replace his lift pump every 15K miles. The best results we'll never know about since if it isn't acting up, the owner/driver isn't likely to comment on it.

After 2002, Dodge went to an in tank sending unit. (again, I got this info off anothe web page, I think it's accurate, but don't shoot me if it's not;) )

This leads me to believe that the pre '98 cummins lift pumps are the better lift pumps. I didn't find any discussion about them on the net, so maybe they just do their job and nobody pays attention to them..


I was looking at my IP inlet barb last weekend. I've been leaning towards Tim's "Feeding the Beast" mod. One observation that I made is that the hose from filter to IP has a 90 deg bend in it at the LP. This may be a source of restriction.

Slightly off topic, but when I did the cummins lift pump google search, I found a page where a guy was describing his fuel delivery mods on his tractor trailer with common rail IP. He was getting good pressure at one point and zero pressure further down the line. He said that he replaced his rubber fuel lines with copper, because the old rubber hoses had swelled after prolonged diesel fuel exposure. Anybody know if this happens on our trucks. My truck is over 10 years old. I imagine that's enough time for things to swell up if our fuel lines are going to react.

Couple whiskey's and I can't stop typing.... There Done!:)

I'd use aluminum or steel line because iirc BIO attacks copper and we all know what direction the country is headed in regarding the use of BIO blends.

Cummins problems are why I'm using it as an augment pump when I need extra grunt, I would not use that pump solo, as for hose evenntually I'll be running braided stainless, I'll get for free off of a scrapped out jet engine I come across every now and again

I have A fuel leak on the return line to my tank. It's on the rubber piece between the tank and the frame rail. The rubber line itself looks great but both ends of it are badly rusted and I think thats where the leak is comming from. The rest of the line is steel and appears to be in good shape. I would like to know how much pressure is on this line and if I can get one at A local auto parts store? It only leaks when shut off overnight, wipe it all dry and drive it and it stays dry. I dont want to take it apart and not be able to get parts quickly as I need to take A 200 mile trip with it Sunday but don't want to drive it that far without repairing it. Thanks, Jr

I have A fuel leak on the return line to my tank. It's on the rubber piece between the tank and the frame rail. The rubber line itself looks great but both ends of it are badly rusted and I think thats where the leak is comming from. The rest of the line is steel and appears to be in good shape. I would like to know how much pressure is on this line and if I can get one at A local auto parts store? It only leaks when shut off overnight, wipe it all dry and drive it and it stays dry. I dont want to take it apart and not be able to get parts quickly as I need to take A 200 mile trip with it Sunday but don't want to drive it that far without repairing it. Thanks, Jr


there shouldn't be much pressure on the return line. That's a GM specific hose. I'd say it's a dealer only thing, but I think they are discontinued, iirc. Price was around $127. You're better off making your own. Flare a fitting onto the end of the steel tubes and get a new rubber hose to make the connection.