Lift pump seems to work

Jeger · **Posted:** Fri Oct 19, 2007 8:49 pm

Thanks for the update.

Its funny I just had the though tonight that drilling and tapping the banjo bolt would be an easy way to tap in a pressure gauge....what size did you tap in?

Serendipity · **Joined:** Mon Nov 20, 2006 10:51 pm **Posts:** 45

1/8" NPT.

gmctd · **Posted:** Fri Oct 19, 2007 9:10 pm

Need to verify the flow-rate of that Lucas pump in gph - is the mfr label or p\n still visible?

Also, put a 0.020"dia orifice in the pressure gage base to remove the pumping pulsations

Serendipity · **Joined:** Mon Nov 20, 2006 10:51 pm **Posts:** 45

The only number on the pump is E1004. I haven't found a cross reference for this pump yet, but it is about 10 years old. I could time how long it takes to fill a 5 gallon container and get fairly close to the GPH. The pulsation was fixed by a needle valve. I figured it would be a little more versatile than a dedicated gauge snubber.

warp2diesel · **Posted:** Fri Oct 19, 2007 9:49 pm

Good quality gauges often have a small screw in the inlet port to restrict the flow and dampen out the needle vibration, tighten the screw a little if you have one. If you gauge does not have a screw you could put a dimple in the area around the hole with a small center punch to reduce the flow and dampen out the vibration.

Steve

Serendipity · **Joined:** Mon Nov 20, 2006 10:51 pm **Posts:** 45

The gauge is cheap. It has a porous piece of brass in the inlet. I had hoped this would dampen it, but it didn't. The needle valve did the trick by restricting the flow, and it is adjustable too. The column of air in the hose also provides a cushion, but I can't count on it staying in the hose.

Anomious · **Posted:** Fri Oct 19, 2007 10:07 pm

Part No.
P74019 Carter Fuel Pump: Universal; Electric; 12 Volt
Fuel Pump: Universal; Electric; 12 Volt
Warranty: 1 Year Limited Warranty Not lifetime warranty...

Ships in 1 day
$43.99

I still don't know which one to buy. LK

gmctd · **Posted:** Fri Oct 19, 2007 10:17 pm

Or, just do a quart and interpolate......................

Serendipity · **Joined:** Mon Nov 20, 2006 10:51 pm **Posts:** 45

I just figured 5 gallons would make errors fairly insignificant. It would do a quart pretty quick. I rarely have help when I do this stuff so I try to make plans that are easy to do alone.

gmctd · **Posted:** Fri Oct 19, 2007 11:09 pm

Thinkin' out loud here - the pulsations indicate the pump is low-volume, or the valves are leaking - it's not keeping up with demand (thus the pulsation), so may be ~15gph, suitable for a euro ~2.0L 4-cyl gasser (patooie!), but not for a 2.8L CRD turbodiesel at WOT.

30gph, like the Facet 109\equiv will help, if your WOT experience occurs at some duration greater than driving at some lesser throttle angle.

IMO, of course...................

BTW - I just wanted to tell all you guys that I do recognize that you've put some considerable time in on this and other stuff - lift pump, transmission, coolers, filters, emissions, etc - B4 I came aboard, and I appreciate and professionally commend your time and effort in solving the problems with this little mule.

I just retired from my own career as professional troubleshooter in computers and process control, and as my lifelong hobby has been the infernal combustion engine in various wheeled environments, I tend to note what has gone before, then approach any problems from my experience and viewpoint, with no intent to offend - I am driven to know the why of it

So, thanks for your efforts and solutions - and, now back to your regularly assigned programming.............

retmil46 · **Posted:** Sat Oct 20, 2007 11:59 am

I installed one of the Mr Gasket 15 psi gauges downstream of both filters the other day. Key on engine off, operating off 12.5 volts from the battery, the Kennedy pump supplied 3 psi downstream of the filters. Engine running at idle, 14 volts from the alternator, it supplied roughly 3.75 psi downstream of the filters. No pulsations, nice steady pressure due to being a centrifugal pump.

gmctd · **Posted:** Sat Oct 20, 2007 1:32 pm

Correct - with added benefit that it is a magnetically-coupled pump - the motor shaft spins a magnet which drives a magnet in the pump rotor - the motor and pump are isolated into separate housings, requiring no rotary seals - added benefit is the pump can supply rated volume as required, but not cause aeration at lower volume demand - the rotor simply slows as demand decreases - the motor can maintain constant rpm due to the magnetic coupling.

Normal rotary pumps are directly driven and usually positive displacement - if demand requires rated volume, everything is copasetic, fuel flows, engine runs, no fuel aeration - however, if demand falls way below rated volume, the hard-driven rotor then churns the fuel into frothy meringue, not even good for carburetion, much less injected Diesel systems.

Where demand requires a rotary positive displacement pump, the ECU usually controls pump motor speed according to demand.

Low output Diesel systems usually function best with the easily applied solenoid-shuttle pulsed flow type pump - modern shuttle-type pumps are electronically driven, where internal solid-state circuitry shuts down at rated pressure - these can maintain pressure at minimal or normal demand, but may drop off at high demand - it's not really a big deal as long as positive pressure is maintained at all demand levels - even 1/2psi at WOT equates to more volume than the engine requires.

Lift pumps for Diesel service are purposely spec'ed at low ratings to prevent aeration of warm Diesel fuel in normal street use - hi-performance and racing applications require increased volume and pressure - but, the upgraded fuel supply can be detrimental when granny uses the vehicle to get her hadacol from the local drug emporium
This becomes a really big problem where the performance-enhanced vehicle is hard-flogged at the track, then easily driven home on the street with all conveniences in-place and functional, incl the a\c

Long story short - that magnetic-drive type pump is excellent for this service, but way too expensive for my purposes, as the pulsed solenoid-shuttle pumps are equally functional.

A primary requirement is that each be flow-thru at fail, such that the CP3 can draw fuel from the tank to get you home

retmil46 · **Posted:** Sat Oct 20, 2007 3:34 pm

Other day I got to experimenting with the old '87 MB. Mechanical injection pump, with a mechanical pushrod plunger type supply pump mounted on the side of the high pressure injection pump operated by an internal cam. I'd seen on some of the MB parts websites where some people had experimented with adding a Walbro lift pump back by the tank for when they ran SVO, and commented that even on regular diesel it had put some spring back in the car's step, making up for a tired mechanical supply pump.

Specs on the supply pump from the W124 FSM stated that delivery should be 300 cc/min cranking at 150 rpm, minimum pressure specs > 4 1/2 psi at idle and > 7 psi at WOT, measured downstream of the filters.

Supply from the tank isn't a problem - it's mounted up inside between the rear seat and the trunk, fuel will gravity drain quite readily when you disconnect the supply hose in the engine bay. But first it has to get sucked thru a mechanical fuel thermostat and coolant heater before getting to the suction of the supply pump.

I've got one of the 7 psi Facet thumper pumps that's been sitting around for a few years from another project. I tried plumbing it in prior to the mechanical pump, in series supplying suction pressure. Didn't seem to make much difference at idle, except for smoothing it out some. Didn't have a pressure gauge installed at the time and wasn't able to learn much.

Since then I've installed a 15 psi gauge in the line prescribed by the FSM. At idle the pressure swings rapidly back and forth between about 6 and 9 psi. Once sped up to around 1000 rpm or above, the pressure pretty much steadies out at 9 psi, and climbs up to around 12 psi when sped up to highway rpm.

Old beast has quite a pronounced metallic clack at idle, two things I noticed - at idle, the clack seemed to be in time with the swings of the pressure gauge, and once rpm had picked up enough to where pressure stabilized at 9 psi, the clack disappeared. Perhaps some injector nailing caused by insufficient supply pressure to the injection pump?

Gonna do a little more experimenting over the weekend, try the Facet pump again in series and then in parallel with the installed pump, and bypassing the thermostat on the suction side in case that beast is sucking air.

Bill.Barg · **Posted:** Sat Oct 20, 2007 3:58 pm

I checked into this option for a lift pump;

http://www.heathdiesel.com/P/HDP1300/

No tech info on the website. I asked for more details and got this;

Ian from HDP wrote;

"The pump puts out around 9 psi at idle and should maintain above 3 psi under
full load conditions."

They were unable to tell me what size fitting it has, however.

GMCTD.... do you think is this a solenoid type pump?

Any ideas if this is an option for us?

Bill

Joe Romas · **Posted:** Sat Oct 20, 2007 4:04 pm

Retmil.

On your Benz clatter.

I had a injector hang on a rabbit years ago and it sounded just like a rod knock :shock:

A few years later (1982) I owned a Datsun diesel pickup. It started banging one day so I took it to the dealer and told then the knock was being caused by a sticking injector

They thought "what does a dumb customer know

When I picked it up the service manager wanted how I knew what it was :lol:

Your metalic knock may be caused by a sticking one. Use the old screw driver to the ear trick and listen to each injector

Anomious · **Posted:** Sat Oct 20, 2007 4:40 pm

On a Benz that clatter usually called nailing is most often caused by a leaking pressure valve holder seal. They are cheap and easy to replace. It does take a weird wrench to loosen them.

I curse the day when I traded my "86" 300SDL for this jeep.
It had no rust, got 27 mpg, cruised at 130 and was reliable!

stupid-> LK :cry:

P.S. It would chirp the tires going into second!!

gmctd · **Posted:** Sat Oct 20, 2007 4:49 pm

Correct, Bill - that is one of the GM lp's I referred to back when I first signed on - it is flow-thru shuttle-solenoid type, for the '93 GM 6.5L TD 3500 4wd, commonly available at NAPA, O'Reilley's, etc - the fittings are metric o-ringed hi-pressure - you can cut the steel pipes and fittings from any of the '89-up 1500-3500 GM trucks in your local boneyard - the gassers (patooie!) have the fuel filter on the frame rail, the Diesel's have that lift pump at the same location - just take the lp with you for correct fitment, and don't overlook the o-rings.

As you may know, retmil46, series-stacking pumps can have the result of stacking pressure - if the MB requires 4.5-7.5psi at the IP, adding the 10psi Facet at the tank can result in 14.5-17.5psi at the IP, depending on how that pressure is regulated in the MB lift pump.

Far as the clacking, I'd use Joe's method of screwdriver-o-scope - the IP could use the hammer\anvil escapement method of effectively doubling pumping action at cranking rpm, disabling it with fly-weights as shaft rpm increased - that could account for the clacking.

Inet_CRD · **Posted:** Tue Oct 23, 2007 3:01 pm

Installed the Kennedy Diesel lift pump two weeks ago, big Thanks to all the contributers on this site! Made use of the 'factory' lift pump wiring, the 'factory' M12 threaded bolt on the frame rail beside the fuel tank for mounting, and Retmil's suggestion for the quick connector fuel repair kits for near 'factory' connection to the fuel line from the tank. I am happy to report the following:

Sh Sh Sh Sh udder at 55 - Completley gone. I used to get the 55 shudder every time after hard accelleration. Now it's COMPLETELY GONE.
Smooth consistant starts - No more intermittant 8-10 seconds of cranking to start. Now starts consistantly with 2 revoloutions, EVERY TIME.
May be my perception but off idle and low RPM performance seems WAY UP. Actually squeeled the tires unintentionally at a set of lights the other day.
Fuel primer is FIRM. Have checked several times and is firm with less than 1/4 of a squeeze.

Best $100.00 I've spent on the CRD yet!

1TDI4Me · **Posted:** Tue Oct 23, 2007 4:13 pm

INET CRD,
I would like to know if the lift pump is the solution for air collection in the
filter housing. Could you report back after a couple thousand miles and
tell us how much air bleeds out? Then we would be closer to determining
if the air is comming from the housing unit or from vacuum effect on the
fuel gassifying disolved air in the fuel. All this assumes you haven't
changed to an aftermarket filter setup.

Thanks

Stan Wright · **Posted:** Tue Oct 23, 2007 4:53 pm

Inet_CRD wrote:

...May be my perception but off idle and low RPM performance seems WAY UP...

Myself and others have noticed the same thing. The normally-aspirated part of the engine feels stronger.

Lift pump seems to work

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