Porsche MFI fuel pump conversion

[DJRporsche]

Hi everyone,

I need to change my failed fuel pump for my MFI system. I understand that a new fuel pump, which is not manufactured by Bosch any more (Porsche part 90160810500 or Borsch 0580970001) costs in the $400+ range. I have seen other forum posts with discussion on how you can use a Holley pump or other pumps with additional components to get the correct pressure in addition to using the return line, but no one actually fully explains a step by step of what needs to be changed or included a diagram for assurance.

Can anyone tell me which fuel pump and additional components I need to use, and how they would need to be arranged correctly (including part numbers). If there is a diagram included to help that would be perfect.

THANKS
Doug.

[Jim727]

My pump failed (also for MFI) and we got a rebuilt pump from http://www.fuelinjectioncorp.com/ - only about 500 miles ago, but working well so far. Pumps for carbs won't work.

Jim

[pjh69911]

I would guess any cis pump would be able to supply adequate pressure and volume for MFI. The filter console on MFI has a pressure regulator/relief valve thet will control pressure as long as there is adequate volume and the pump is rated over 1-2 atm. I have such an arrangement on a MFI Mercedes with no ill effects. Paul.

[donyount]

Ours failed and we added a pump from a turbo volvo that had simmilar output. Will let you know or i will follow this thread. Ran fine up to 3500 rpm and acted like its out of gas. We will hook up fuel pressure reader tomorrow to see. don

[sballard]

Parts Heaven has rebuilt ones but they are pricey.

Most experts here insist that the original spec Bosch pumps are required for MFI. LOTS of discussions on this in the archives.

[GrantG]

Jerry Woods Enterprises hooked me up with an aftermarket pump (forget the type) with Fuel Pressure Regulator that works great. You can call them at 800-383-0808 (ask for Rich).

[MikeDL]

I bought one for ~$450 on ebay from FuelPumpKing1 (no affiliation), and received it tonight. It appears to be the right pump based on the Bosch part number stamped into the case, and looks new.

There are five available, item 370103595013

[Biff]

I also purchased one from fuelpumpking1. Haven't installed yet, but its not the exact same size (smaller) and inlet/outlet orifice are different.

[Rot 911]

This guy has 2 of them for sale in the classifieds: MFI fuel pumps for sale

[obrut]

mine recently failed and was replaced with a new 'generic' electric fuel pump. it is a little noisier than the original unit but was a fraction of the price and works perfectly.

[tharbert]

I wonder if a correctly spec'ed main pump and a smaller scavenger pump to pull gas from the MFI back to the fuel tank would be fine? $500 for a fuel pump? There must be a more elegant solution.

[geshaghi]

Reviving this old thread. I'm also looking for 901 608 105 00 pump. I see that fuelnjectionking still sells these on ebay, but they look a bit smaller than the original pump. Any idea if the pump is correct or just a re-marked 914 pump? Has anyone had any luck with any other pump solutions? I've seen the thread on rebuilding these, but I am returning a car from carbs to mfi, so I don't have a correct core to even rebuild. Thanks

[tharbert]

It's funny you should ask. Someone started to have this same discussion a few days ago. Look here.

[al lkosmal]

I recently purchased a pump from fuelpumpking1 on Ebay. Part marked correctly, but it is a bit smaller, inlet diameter is smaller and the outlet and return positions are swapped. I have it hooked up to my 2.2E engine, on the test stand and it appears to work well.

Regards,

Al

[356RS]

I also tried one of the short "fuelpumpking1" pumps on the MFI flow bench and found that while the pressure read 1.1 bar when testing an MFI pump @ 500rpm, it went down to almost "0" bar at 3000 MFI pump rpm @ full throttle. At 3500 it was cavitiating. A good working 001 MFI fuel pump will stay at .4 bar when pushed to the 3500 pump RPM @ full throttle on a 2.2S MFI pump.

[geshaghi]

Al - Would love to hear how this works once you get your motor in the car. I need something for a 2.4E motor, and this is the last piece I need before I can put it back in the car.

Mark - Have you found any other solutions? The Holley pumps don't seem to be plug & play - it looks like the need some fabrication or add-on parts to work correctly in an MFI system?

[356RS]

George, I'm working on some solutions now.

[geshaghi]

Anyone had any luck with the solutions mentioned or an aftermarket pump? Zims has a replacement pump listed for $249 with no returnm here's the link:
Zims Replacement Fuel Pump for 911 69-73 w/MFI
Anyone try this yet?

[Flieger]

No return = no go. That pump is for carbs. It cannot flow enough to feed the MFI injection pump thorough all operating parameters. If it did, it would need the return line for the excess flow. The recirculating fuel also is a significant part of the MFI injection pump's intended cooling system design. That fuel flow helps carry the heat away and keeps the throttle response nice and snappy.

[geshaghi]

Originally Posted by Flieger

No return = no go. That pump is for carbs. It cannot flow enough to feed the MFI injection pump thorough all operating parameters. If it did, it would need the return line for the excess flow. The recirculating fuel also is a significant part of the MFI injection pump's intended cooling system design. That fuel flow helps carry the heat away and keeps the throttle response nice and snappy.

So the Zims part won't work then, despite the express claim that is is for 69-73 MFI systems and the statement in their instructions that "The new pump does not need or have a provision for this return line."? Has anyone actually tried this pump? If the Zims product won't work, does that leave only a rebuild as an option? Anyone have any sources for this? I still haven't heard of anyone's experience using the pump offered by Fuelpumking on eBay (see PORSCHE FUEL PUMP NEW 0580970001 1973-69:eBay Motors (item 370270867099 end time Feb-03-10 02:37:57 PST) ). Part no. is correct but the pump looks a little different.