Mechanical lift pump to electric conversion

[opusd2]

NOW!

I completely understand why most people upgrade from the mechanical lift pump to an electric unit - the electric pump is so much easier to install. That mechanical pump is a real ***** to try and install! I'm pretty much committed to finishing the job tonight by putting the new mechanical guy in there, but I am just swearing at the lack of room and messed up angles with which I need to work. I have to figure out this pig and get it in tonight as I am only parked halfway into the girlfriend's garage and the city has shown more crime all the time.

Had I known earlier it was 10 pounds of **** in a 2 pound bag, there would be a little electric guy down on the frame. Oh well, live and learn...

 

[MIDNIGHT RIDER]

I don't remember it being such a hassle when I had to remove/replace the mechanical-pump on my old 6.9.

As best I remember, there was nothing wrong with the pump, but I had to remove it to replace a line that had split or some-such.

If I had it to do over, I would replace the fittings with JIC adapters, replace the hard-lines with rubber/JIC, and put studs in the bolt-holes.

A little planning ahead like that can make a tough job into a simple chore.


I would also go ahead and plumb in an electric-pump; NOT for the main pump, but as a stand-by, and for priming the system.

 

[Exekiel69]

Yes the angles on the IDI for the lift pump are a little difficult that was one of the reasons I changed to a electric pump.

Good thing is now the location for the piston pump I'll install on the cummins is right where I can just bolt it ON.

 

[opusd2]

I KNEW posting would bring some good ideas! Just going with a set of studs would bring the job to a quick completion. And I have thought of an electric pump both as backup and for priming purposes would really simplify the problem. Plus, ever since the pump wet out that was on the truck when I took control of it, it has used a gravity fed system with a combine tank in the bed which worked great on the farm before I bought it, and even after I bought it. But now I just wanted to take advantage of the stock twin tanks on-board. But maybe keep the pony tank for used ATF mixed with K1 or something fun like that, ported off manually. Who knows...? At least hooked to a feed pump it is legal. The colored contents, not so sure...

The truck looks like a mess, and sure needs a LOT more work than I knew of when it was just a farm truck I drove off road only. But since I took possession of it and decided to make all of the little things work, it has snowballed into one hell of a project. But it's been a lot of fun, especially since I got the truck to gain 6 mpg with just simple work, and running my own blend of chemicals through the system I usually run through my vehicles to clean things up. And then there's the Power Service I am running to add some lubricity to the system...

After this mess I am hitting the cruise control system and am hoping to find the failure. The diesel just runs so damn smooth that it gains speed so easily I don't notice I am doing much higher speeds than I want to, or should be. Even with the 4:10s.

I am still so amazed that I never considered studs for this. It would make it so much easier. So guess what I am doing first thing in the morning!

 

[MIDNIGHT RIDER]

On the Cummins, I up-graded to a piston-lift-pump.

Advantages are steady 16-PSI after several filters/seperators/etc., no diaphragm to rupture and pour fuel into the crank-case, strong manual primer-pump that will develop as much pressure by hand as it will with engine running, and completely rebuildable should it ever need so.


I then incorporated a Carter electric-pump in a check-valve protected "BY-PASS" line.

This electric-pump is plumbed/wired to perform a host of useful duties.

It can take over and run the truck, should the mechanical-pump ever fail.

It will fill and bleed all the various filters, sediment-bowls, bacteria-killers, and water-seperators, while purging any trapped air.

It will prime the system, completely negating the need for any "line cracking", whenever the engine happens to run dry of fuel, usually firing at the first piston lift, with no bleeding necessary.

I have THREE tanks, plumbed via TWO manual fuel-selector valves, one is DRAW, the other is RETURN; I have a RETURN-line by-pass valve that I can set to pull fuel out of any tank and return it into any other tank, without that fuel passing through the injection-pump.(this little convenience is more useful than it would first seem, such as being able to relocate fuel out of a tank that might need some sort of repair)

I also have a valved Quik-Couple, along with a removable/stowable hose, that I can pump fuel out of any tank I choose and into anything from a pop-bottle to a bull-dozer.

These are just a few of the many conveniences that can be had with an electric-pump and a little imagination.

 

[Mat J]

I am going to go electric on mine soon . I just want to save myself trouble in the future with the lift pump and to help bleed the system.

Can an electric pump be used along with the stock lift pump or does it need to just be blocked off?

 

[opusd2]

Well, I will definitely say that there is a distinct advantage to having a lift pump versus a gravity fed system. I swear I have a new truck now. And there's even a **** of particulates out the tail pipe to show I have a better feed. Plus, when I just give it a rumble when she is sitting, the torque from the engine almost twists the body into a full helix. It was worth the headaches it took to replace the stock mechanical pump.

At some point (when I have the funds) I plan on plumbing a electric pump into the system as both backup, and for moving the fuel around, etc... I still have the piggy back tank plumbed in via manual valve, but it's just there for backup. The best part is that I had absolutely NO problems with air in the line. I guess if you can't be good, be lucky!

I really want to keep the engine as free of electrics as much as possible, and in fact would love to convert the shutoff on the IP to a manual lever or cable. That's just what I want, something as close to a tractor engine as possible that can run without any battery source if necessary. But it is going to have that backup electric pump in the future just in case, of who knows????

 

[snicklas]

I am going to go electric on mine soon . I just want to save myself trouble in the future with the lift pump and to help bleed the system.

Can an electric pump be used along with the stock lift pump or does it need to just be blocked off?

Mat,

If you are wanting to have both, you will need to plum in a bypass and run one of the other. If you run an electric throught the machanical lift pump, eventually the pressure against the diaphragm in the mechanical pump will rupture and fill the crankcase with diesel.... unfortnually diesel is not a good engine lubricant. There are some members here that have a bypass system set up so they can run the truck off the mechanical, or the electric pump. Some even have 2 electric pumps set up in a bypass for a "belt and suspenders" type of backup.

If you do remove the mechanical pump completely, a Big Block Chevy fuel pump block off plate is a direct bolt in cover.....

 

[MIDNIGHT RIDER]

If you do remove the mechanical pump completely, a Big Block Chevy fuel pump block off plate is a direct bolt in cover.....

This leads me to ask a question that I have been pondering over for years.

I have read in numerous applications to use a "big block Chevy" pump block-off plate; then I have also read that there is no difference in the plate for big block or small block.

This has made me wonder just how much difference is there in mechanical fuel-pumps from one engine to another.

The distance and elevation of the cam-shaft in relation to the pump-flange is the only governing factor in pump-lever length/shape.

Is it maybe possible that the flange and bolt-pattern of most all lift-pumps is the same ??

Thanks.

 

[Agnem]

then I have also read that there is no difference in the plate for big block or small block.

.

Ask my son who made the mistake of not verifying with his own eyes what the guy at the chrome parts counter thought he was giving him. He hands it to me all proud saying "I got the block off plate you told me to get dad". I looked at the front of the package for about 100 milliseconds, then handed it back to him saying "read the back". (Dad's love doing this.... guessing wildly that it will say Chevy small block without actually looking, thus appearing to have x-ray vision). It was indeed for a small block, and despite whatever you have read, it was obviously not written by someone who had to make 2 50 mile round trips to get what they wanted.

 

[razorback]

something that i dont know if everyone does, but id reccomend installing a shut off valve before it goes into the fuel filter-the pump that way when you change filters, you dont get a bath in diesel.. i used a simple "gas" shut off valve i got from lowes.