I just installed a lift pump pressure gauge to the fuel hose between the fuel filter and the IP inlet. It reads: 0 (zero) PSI... I can only guess that it's the lift pump. I am gettting a trickle of fuel from the T-valve but not a stream. I just put in a 5068 IP-under 300 miles- and I don't want to burn it out so I'm going to pick up a new supply pump in the morning and install it. The fuel filter is new - under 300 miles - should I change it as well? Also; could it be the OPS? I know that this is the way of the 6.5 but will I ever get a sense of security I so long??? WTF???
:rant:

Thanks in advance for any forthcoming advice.
Ed

That 0 at idle? is the pump runing at idle (feel the body it should be purring), if not Quick test unplug the connector to lift pump while running you should have 12v across the 2, if you do have power then shutdown & slave in a fused temporary wire direct to the lift pump with a manual switch pump shold remain on if it was running at idle, then go for a test drive if your gauge drops off with direct power pump needs replacing 4-5psi at idle is norm, dropping to 2 then recover to about 4 while lightly loaded on hiway if you drop below 2 heading toward 0 pump needs to go.

If pump maintains delivery while direct wired then OPS is failing under load, unless you really need it rite away, I'd take a close look at Kennedys's including the OPS bypass control as a replacement or Heath's they have higher output pumps than the OEM, and still maintain flow thru on fail design that wont leave you completely dead by the road side; I recently installed a Heath lift pump myself most of the time I'm hitting 8-9 psi idle, never drops below 5 "gittin on it".

I recently installed a Heath lift pump myself most of the time I'm hitting 8-9 psi idle, never drops below 5 "gittin on it".

Was that a direct replacement TD? Was it the FP905 or FP902 Delphi unit(s)?

T I recently installed a Heath lift pump myself most of the time I'm hitting 8-9 psi idle, never drops below 5 "gittin on it".
Carter fuel pumps package a kit for RV's P4602RV - Producing 5 3/4 psi max and 72gph good for gas and/or Diesel. Fuel will not draw thru so the factory included fittings to install a bypass and check valve - SO I WAS THINKIN.... As long as I am fitting a vaccum switch to tell me when my new fuel prefilter is plugging - Like you have - why not fit a normaly closed very low pressure switch at the manual drain (maybe 2psi). When it closes it could energise this new RV pump!
One step further I should I tie it into the OPS relay so it cannot run without oil pressure! But maybe Ill just use the ops relay power to close a second relay - (here we go) and draw 12v from an independent circuit - should my Lift pump fuse blow...... I really should just fix my low boost but thats this weekend. Rick

[quote=Turbine Doc;1130301]I'd take a close look at Kennedys's including the OPS bypass control as a replacement.quote]

Installed a new OPS. Have pressure – 6psi at idle at start up then drops to 3psi at idle after warm up. It dropped to 1.5psi at idle a few times but came back up to 3psi at idle after a run down the road. I’m guessing that the LP is going as per TD tips and one of my local shop has a Carter P74143 in stock. No specs on it but it has a lifetime warranty??? Anybody got anything on this pump? Output high ?

TurbineDoc, thanks for the tips and suggestion on Kennedy’s setup – it looks like the way to go.

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