Fuel Pump Replacements 1973.5 CIS

[HarryD]

Hi All,

I suspect my fuel pump may be on it's way out due to some high speed acceleration issues. I am thinking it will be prudent to have one ready for the "day".

I see this one in the Pelican Catalog:

https://www.pelicanparts.com/More_Info/91160811056.htm?pn=911-608-110-56-M14&bc=c&SVSVSI=4247

It says "Only for cars with CIS fuel injection. This brand is a universal type replacement. Minor modifications may be required for installation."

Does anyone know what mods are needed to install this on my 1973.5 car with the fuel pump under the rear seat?

TIA

[PeteKz]

Harry, that's what I'm using on my 1973T with the 3.2 CIS engine (the one you drove). It's not hard to adapt. But before you go down that road, do a fuel pump delivery test to see if the pump is below spec. Don't forget about the fuel filter and the strainer in the bottom of the tank. They might be restricting flow.

[E Sully]

BoxterGT, Len Cummings has helped out with correct lines for things like this. I would say contact him and see what can be done. Len.Cummings@verizon.net

[BoxsterGT]

Just came across this, and thank you E Sully for your recommendation.

I have done quite a few fuel system upgrades for the 73.5 & 74 CIS models using the latest Bosch "Flow-Through" fuel Pump.

This can be mounted in the original rear location....



or can be upgraded to the later 76 - 89 fuel system layout with this same Bosch "Flow-Through" Pump......



...mounted up front with my custom front pump mount.

For info, please email me: len.cummings @ verizon.net but without the spaces.

I am happy to help.

Len

[HarryD]

Thanks all.

I am kind of a DIY guy when given the chance (like to exercise my engineering brain).

My question: Is the high pressure from the pump to the engine room one piece including the rigid line section that passes through the wall into the engine room? From what I tell, the line starts at the banjo (at the pump), becomes a flexible hose and then is connected to a rigid line that enters the engine room. A separate flexible line connects the hard line to the accumulator.

[eastbay]

Originally Posted by HarryD

Thanks all.

I am kind of a DIY guy when given the chance (like to exercise my engineering brain).

My question: Is the high pressure from the pump to the engine room one piece including the rigid line section that passes through the wall into the engine room? From what I tell, the line starts at the banjo (at the pump), becomes a flexible hose and then is connected to a rigid line that enters the engine room. A separate flexible line connects the hard line to the accumulator.

My 74 is set up just like that, many parts and pieces for one line. Very Rube Goldbergian. In 75 they went to a one piece polymid line from FP to FA before moving the pump up front in 76.

No reason you couldn't or shouldn't go all one piece from FP to FA.

I kept the original piecemeal system in my car because I'm easily amused by quirkiness and looking at it makes me smile. (car lives on a lift)


Pic of as purchased

[HarryD]

Originally Posted by eastbay

My 74 is set up just like that, many parts and pieces for one line. Very Rube Goldbergian. In 75 they went to a one piece polymid line from FP to FA before moving the pump up front in 76.

No reason you couldn't or shouldn't go all one piece from FP to FA.

I kept the original piecemeal system in my car because I'm easily amused by quirkiness and looking at it makes me smile. (car lives on a lift)


Pic of as purchased

Thanks! I'll probably stick with the Rube Goldberg setup as well.

I'll pull the line and see if I need to bring it to my hose shop to get some crimps made. At a minimum I will replace the flexible rubber line.

[BoxsterGT]

This Bosch "Flow-Through" Fuel Pump upgrade I offer eliminates the multiple connections and hose clamps used by the factory.....







This hose is E85 Rated and is expected to last for the lifetime of the 911. It is one-piece from Pump to Accumulator.

It essentially matches the hose routing from the 75 models through to the 89 3.2 Carrera.

Our host offers this Bosch "Flow-Through" pump for under $150 if I remember correctly.

For more information, please email me: len.cummings @ verizon.net but without the spaces.

Len

[HarryD]

Len,

Just sent you an e-mail.

[PeteKz]

Harry, my 1973.5 was like yours too. I removed the hose/metal line/hose arrangement and made a fuel line like Len's except I used hose clamps instead of Len's nicer crimped ferrules. Then I ran the hose from the pump up ahead of the cross brace at the front of the engine bay, which makes it far easier to access and service the FA and filter.

[HarryD]

I have ordered/received the Bosch 69459 Replacement pump.

Sadly, the pump does NOT include any of the miscellaneous parts to complete the install. They did not include:
1-Nuts and washers for the electrical terminals (sourced them from my local ACE Hardware store);
2-Crimp connectors for the wires and the rubber boots to cover the wire and electrical terminals on the pump (I have an assortment of crimp connectors);
3-A 12mm cap nut for the Banjo fitting (furnished to me by Len Cummings along with a custom high pressure fuel line from the pump to the accumulator).

Does anyone know where I can get the rubber boots for the wires?

[rant]I seems silly for the supplier to not provide these parts as most users will need some or all of them. For the supplier, the parts would cost a dollar or two and they would add at least $5 to the product cost for the value added and I would think that most purchasers would not care about the higher cost.[/rant]

[PeteKz]

Harry, When I replaced the pump in my 1973.5, I didn't use the boots. 6 years later, and still running. I think it's fine without them.

[HarryD]

Originally Posted by PeteKz

Harry, When I replaced the pump in my 1973.5, I didn't use the boots. 6 years later, and still running. I think it's fine without them.

Pete. Thanks for your thoughts. I will most likely end up in the same place.

However, it would be nice to give the install a finished factory look.

[PeteKz]

That sounds like a "winter project" to me!

[HarryD]

Finally got around to replacing my fuel pump. My current one was installed in mid 1980 and was making noises. At a HPDE track day, I was unable to rev over 5000 rpm. Replacement of the fuel filter and tank screen allowed the car to rev to 6500 again but it got me thinking that my pump was weak.

I bought the universal Bosch Replacement pump as the "official" Porsche one cost over $800 and the universal unit was under $100. I ordered a replacement pressure line from Len Cummings (Boxster98).

My friend Bob generously allowed me to use his lift to perform the work.

Old pump in it's cradle under the left passenger seat.



Old pump removed from it's cradle under the left passenger seat.







New pump installed in cradle.





The line from the fuel Tank was 10 mm but the pump inlet was 12 mm. Bob made me an adapter.



The new pressure line was routed into the engine room as shown by the yellow line.



And connected to the Accumulator.



Interestingly, the power to the pump was a blue and black wire. The blue was 12v and the black was ground. Added a pigtail to the factory wiring to reach the terminals on the new pump.

Started car with no incident and drove home in Stop and Go traffic without drama.

[PeteKz]

Yup, the wires to the pump are blue and black. Those go up to a connector on the left side of the engine bay, into the wiring harness. On the other side of the harness connector are the wire colors in the wiring diagram.

Good to hear you get her done.

[HarryD]

I was not happy with how I initially routed the fuel hose in the engine room. I moved it around to what I think is a better way. It enters the engine room along the fuel return line.

[PeteKz]

I decided to run my fuel hose up from the pump between the firewall and the crossmember, to the accumulator. It was the easiest routing.

[fintstone]

Harry...Nice work. I just swapped my similar pump for the Bosch 69459 pump as well. I need the same line and nut from Len as my old custom line is staring to weep a bit.

Not to be critical, but don't you have your filter (in your accumulator photo) turned around (with the inlet and outlet swapped)?

[HarryD]

Originally Posted by fintstone

Harry...Nice work. I just swapped my similar pump for the Bosch 69459 pump as well. I need the same line and nut from Len as my old custom line is staring to weep a bit.

Not to be critical, but don't you have your filter (in your accumulator photo) turned around (with the inlet and outlet swapped)?

Thanks. Interestingly, my filter flows the other way.



Looking at my collection of filters from left to right, you will note the leftmost 079 flows differently than the 016 and 003.