dpearl, how is the Stanadyne 5 mic pre working?

[CntrlCalDmax]

dpearl river,

Just wanted to know how your Stanadyne 5 micron pre filter with lift pump is working out. How often do you have to change the element? Do you notice any benifet or problems from the lift pump?
I am thinking about installing one and would like you commnets.

I am fighting an air leak up stream of my JK post oem secondary filter. I'm thinking the lift pump would give positive pressure and eliminate the air getting into the system.

Leo

[srubrn]

You might want to re-think about putting a lift pump on your truck. The engineer at Stanadyne told me that would not be good idea. He mentioned some technical jargon that was over my head about the factory fuel pump was not designed to be fed fuel and told me it might damage the OEM pump. He also agrees with "Racor" about the use of even a 10 micron pre-filter and let the OEM filter do the rest. I am running a Stanadyne 2 micron filter. They just don't last long. I did go to a bigger 2 micron filter and I don't know yet how long it will last. It only has 1k miles on it.

[dpearl river]

CntrlCalDmax,

Well no problems with the Stanadyne lift pump. I do not have a lot of miles on the 5 micron element (approx. 3500 miles). However, towed a flatbed trailer & Ford Tractor last week with no problems on acceleration or cruising speed. Rig was probably around 15K pounds total.

As to Srubrn's comments from the engineer at Stanadyne: I recieved conflicting information about a lift pump. Actually, my investigation into the DMAX pump system revealed that in actualitity, Dmax fuel pump has a prelift pump prior to the injector pump in one unit. Which is unlike Dodge and Ford lift pumps being separate units. Also, the folks at Stanadyne were comfortable with the Dmax have this lift pump onboard. I was informed that a relief valve exists to bypass fuel that is not needed and returned to the tank.

I can say the lift pump solves the problem of manual bleeding the system. Much easier to turn my ignition switch to prime the filters as opposed to manual pumping the OEM filter pump.

The ability to visually check the water bowl on a weekly basis and manually drain it is insurance. I'm not convinced the OEM filter (Racor) is doing an adequate job of removing water from everyone's fuel. The looks of my OEM filter and from everyone else that has posted pics indicates that water maybe wicking into the fuel and destroying those injectors. At least from what I understand about water in the fuel, per Kennedy and Morrison, I don't want it around. I know you can TREAT the fuel - but I like my warranty.

Will keep everyone posted about life of filter and if there are problems as I add miles to the truck.

[CntrlCalDmax]

dpearl river,

Thanks for the reply. I too talked with a very knowlegable tech rep at Standayne today. He assured me that there was no problem installing the lift pump on a Dmax. It puts out only 8 psi should have plenty of flow for our trucks. He also said several have been installed on Dmax trucks and he has not heard of any problems. I'm hoping a small head of pressure on the system will eliminate the air problem.

The only down side of the lift pump is no fuel will flow if the lift pump quits or losses electrical power.

Leo

[ 04-02-2003: Message edited by: CntrlCalDmax ]</p>

[Kennedy]

I have found that pumping the primer up hard (at least on my engine when cold) can cause some odd idle characteristics like deep rattling and loping etc. Hard pumping the primer is past the 10psi reading on the factory restriction gauge. 8psi may be fine, AND the ECM may just need to adjust, but proceed with caution...