fuel pump leaking

[michel richard]

All,

Converting my car to MFI and I've run into an issue.

The fuel pump I got used leaks around the electrical connector. Has anybody tried fixing this ?

I seem to remember a discussion of this somewhere, but I can't find it in any archive.

Alternatively, what happens if I swap the little vane and rollers from that pump onto a 914 D-jet pump ? in other words, did Bosch manufacture a bunch of pumps by using the same motor and using different vanes to alter pressures and volumes ? Seems to me that is something a company might do.

I'm almost done, apart from that.

Michel Richard

[TimW]

You should be able to swap parts between the head and motor, between years, without any problem. I successfully mixed parts from a ’70 and a ’73.

The ’70 is on top, and the ’73 is on the bottom. Note the heads are slightly different.


One gotcha I ran into is that the round plate the ‘70 used is off set slightly. You can see that the space between the gasket mark and the hole itself is not symmetric. If the orientation is off the pump won’t work, and will likely burn out the motor because everything gets jammed up inside.

[michel richard]

Tim,

Great, thanks. What side does the offset go on, or how do I assemble it so it is right ?

TIA

Michel

[TimW]

I was afraid someone might ask me that some day. My answer is “I duno”.

Your best bet is marking the motor body and the head parts on both pumps you intend to use. Then upon reassembly of the good parts make sure you’re lined up correctly. Work in a clean, confined, area so when you drop parts (the seals and/or the little metal cylinders) you don’t loose them or get them all dirty.

Regarding the 4 screws – they will be buggers to get out, but they will come. After all, they probably haven’t moved in 20-some years. Use lots of Liquid Wrench and NO HEAT! Wear gloves so you don’t slip and jam your hand with the Phillips screw driver. And like most things, patients is key. You can probably do the whole thing in under an hour, but if you get sloppy it will just cause you more grief.

The important thing is knowing the offset is there, it’s so close it can go un-noticed if you didn’t know about it. It’s also so close that you can actually reassemble the parts in all four orientations and get different results in each. In one incorrect orientation the pump will spin but not pump fuel, another will jam up the motor and likely burn it out. Of course one way is the correct way, and I don’t remember what that last orientation will do. It’s really only an issue with the two piece heads because of that plate. Regardless of the model the spring relief will always face the same way. Keep track of the orientation by the power connector and not the bracket since it can move.

And of course my lawyer would tell me to remind everyone to use this information at your own risk, it is pumping fuel you know.

[michel richard]

I did'nt mark the little ring when I took the thing apart. I'll just watch it closely when I first put power to it ! Thanks for the heads up.

[TimW]

The thing isn’t exactly the easiest part to install, so you may want to bench test it rather than test it in the car.

Also, the plate on mine obviously has very distinctive wear marks. Yours may too, and they should clue you into the correct orientation.

Good Luck!