fuel pump conversion questions Options

[Scott-thundercat]

hey didnt see this one when i searched- is it possible to use a different fuel pump for our car? i have a pump out of a mercedes 190E. its fuel pressure is 85 lbs. i was wondering- since our regulator would keep it at 34 or whatever- cant i use this one as the excess will just flow to the return on the tank? i'm asking cause i have it sitting here and it would be easy to make it work assuming i wouldnt destroy the fuel system in the car...

[Cap'n Krusty]

You may not yet know me, Scott, but I'm sure you'll become familiar with my attitude "problem" sooner or later. I've spent the last 33 years as a professional German car technician and shop owner.

That said, here's my answer to your question. DON'T DO IT. The regulator isn't made to deal with pressures well over 100PSI, and with the kind of flow rate the MB pump has. Sooner or later, there's gonna be a problem. Furthermore, I sell a lot more of those than I do the 914 pumps, 'cause they go bad all the time.

If you want to convert to a "more modern" design, use the pump made for VW bugs/busses/vanagons and 75-76 914s. Just replace the "Y" fitting in the return line with a straight tube and be done with it. You'll also have to use the later filter and a short piece of 12 mm fuel hose, but that's generally not a problem as they're readily available. BTW, you'll notice I called that setup a "return line". It's not a mechanism for preventing "vapor lock", it's a bleed off of excess fuel pressure at the pump (released by the check valve on the pump itself).

The Cap'n