Who hid the fuel pump!

[555meranda]

I have a late 73 911S Targa and a few weeks ago it "failed to proceed!" this was a fuel problem which I believe by the lack regular noise at start up to be the fuel pump. I quickly reached for 101 Projects for your Porsche 911 which revealed that the pump was under the front of the car and seemed an easy fix. So I then ordered a new pump and filter from or hosts and after a couple of weeks [ I am in Australia] it arrived. Then i put the car on the hoist to find no pump as shown in the book but that the pump was mounted on a factory bracket on the rear cross member and more importantly it was a completely different style of pump. I have two questions . 1 is this style of pump available and if not with end of the replacement pump shown is the input and which is the output!

[75 911s]

Green is your input, black the output. It does look different, but it might work if the specs line up for (what I assume is CIS)

I also have a rear mounted fuel pump. They were rear mounted 73-75.

Here it is using included parts, by removing the end fitting shown in the picture with the black shipping cover, and replacing it with a bolt style fitting that was on the original pump.



Here's the end cap that Len Cummings sells. So you would put the existing fuel banjo over the end and then use the cap. Hey maybe the Bosch comes with the cap?



After replacing the pump I had hot start issues. I figured it was the check valve was somehow defeated in my new pierberg pump with the bolt style fitting.

[buster73]

Just prepared a spare pump for my 73.5 CIS which should be similar to your late 73 model. I used a 90° fitting so the pump will fit in the original orientation and no changes to the fuel hoses will be necessary. You probably will have to extend your wiring because the electrical ports of the new pump are on the "wrong" side.

[Mark Salvetti]

Time out, the 1973S has mechanical fuel injection, not CIS. It has one electric pump near the fuel tank that feeds the MFI pump on the engine. The MFI pump is driven off a camshaft.

I don't know that much about MFI, but I'm surprised the pump was moved to the rear. Do you still have the MFI system in place?'

Mark

[75 911s]

There was a 73 with CIS too.

[buster73]

Late 73 should be model year 74 hence CIS. The old pump shown clearly is an early CIS pump (NLA). Of course MFI would be another story.

[djpateman]

http://www.early911sregistry.org/forums/showthread.php?151025-Fuel-pump-bracket-1971-911T
The research I did found that the fuel pump moved to the rear in Oct 1970.
davep

[Mark Salvetti]

The PO said he had a 1973 911S. That's MFI for the entire 1973 model year. Only the 911T went to CIS.

I'm just wondering if his engine was converted to carbs. Isn't the low-pressure fuel pump that feeds carbs usually located in the engine bay?

Like I said before, I don't know the workings of MFI very well (or carbs), but I'm certain if he has a 1973 911S it should be MFI.

Mark

[Mark Salvetti]

Originally Posted by djpateman

http://www.early911sregistry.org/forums/showthread.php?151025-Fuel-pump-bracket-1971-911T
The research I did found that the fuel pump moved to the rear in Oct 1970.
davep

Dave, that thread is about a 1971 911T, which had factory carbs. Did the fuel pump for MFI engines ever move?

Mark

[75 911s]

OP must have a Model Year 74, with a production of late 73.

[Mark Salvetti]

Yeah, I think you're probably right. And I didn't look at the photo closely enough to see the pump is mounted under the car. I was thinking it was mounted to the cross member between the shock towers inside the engine compartment.

So it's really an early MY1974.

Mark

[djpateman]

Originally Posted by Mark Salvetti

Dave, that thread is about a 1971 911T, which had factory carbs. Did the fuel pump for MFI engines ever move?

Mark

My post in that thread clearly shows that all models changed:
Fuel pump is relocated to the left rear torsion bar tube as of these VIN's.
911T 9111100562 & 9111110790
911E 9111200312 & 9111210244
911S 9111300331 & 9111310214

[555meranda]

Originally Posted by buster73

Just prepared a spare pump for my 73.5 CIS which should be similar to your late 73 model. I used a 90° fitting so the pump will fit in the original orientation and no changes to the fuel hoses will be necessary. You probably will have to extend your wiring because the electrical ports of the new pump are on the "wrong" side.

Thanks for this I managed to obtain one like this from a company called Partsklassic in New York but the pumps no longer come with the rubber glove on the outside. This is not a problem as I can manufacture one from our local rubber supplier. I guess the rubber replaces the original shock mount which is good as mine was in bad condition anyway. I will mount it in the original mount using a big cable tie.

[BoxsterGT]

555meranda-

If your original pump is a "side outlet" as in your photo, then you have a CIS motor.

The original pump is triple or quadruple the cost of this one, so Pelican did you a great service sending this pump.



All you need are the correct hose & fittings like this....



I offer this conversion in E-85 Rated Hose to use with your "Flow-Through" pump. It is routed above the rear firewall crossmember at the Left corner, as with all 76> and later 911 models.

With the higher fuel pressures of CIS, this is a far safer hose routing that eliminates the "hose through the side frame member" with 4 or 5 hose clamp connections.



For more information, please email me: len.cummings at verizon.net

I hope this helps.

Len

[djpateman]

Originally Posted by BoxsterGT

The original pump is triple or quadruple the cost of this one, so Pelican did you a great service sending this pump.

Len, you are correct in so far as the pump can be used. However, they do a disservice by not explaining that it is not a drop in replacement. They should have an included note showing the differences, and explaining what is required to install it and make it useful.
A good thing that you can provide something to aid in the conversion.