Missing fuel pump

930cabman · 09-30-2012, 03:04 PM

My 1975 911S quit a few weeks ago and was flat bedded home, first time. I finally found a little time to explore what is going on. My information tells me the pump is behind the "guard" under the front of the car. I removed the guard to find no pump. Two rubber fuel lines run from the tank to the tunnel. I suppose a prior owner must have moved the pump to the rear of the car for some reason. Has anybody else seen this modification? why?

thanks

dipso · 09-30-2012, 03:07 PM

My 75 had the pump in the rear. I thought that was the stock location.

Quicksilver · 09-30-2012, 03:27 PM

PET shows "for cars with auxiliary support -steel" as having the fuel pump in rear and "for cars with auxiliary support-aluminum" as having a front fuel pump.

930cabman · 09-30-2012, 04:12 PM

Quicksilver,

Thanks for the info, but who/what is PET? My factory manual shows the pump under the "guard" near the steering rack. Our host sells a "universal" for a 1975, is a pump a pump regardless of it's mounting location?

ossiblue · 09-30-2012, 05:39 PM

Quote:

Originally Posted by 930cabman

Quicksilver,

Thanks for the info, but who/what is PET? My factory manual shows the pump under the "guard" near the steering rack. Our host sells a "universal" for a 1975, is a pump a pump regardless of it's mounting location?

75's had the pump in the rear, above the left rear wheel, from the factory. If the "universal" pump you mention is for a 75, the location will not matter. What will matter is the size of the inlet/out ports on the pump and the fittings on the pump.

Now might be a good time to move the replacement pump to the later, factory location--on the front steering beam. It is a better location for the pump in that it is not exposed to the heat from the engine/heat exchangers, and it is easier on the pump to "push" the fuel than it is to "pull" it to the rear. It's not a difficult task and there are lots of threads to show you how to affix the pump to the beam.

spuggy · 09-30-2012, 08:15 PM

Quote:

Originally Posted by 930cabman

Quicksilver,

Thanks for the info, but who/what is PET?

PET is the Porsche Parts catalog. Invaluable resource when you have a car that has some parts that were used for 1 or 2 years only, and you're trying to figure out if they're all the same or not (e.g. if a part from an SC is the same part).

Or what other parts you need to be compatible if you upgrade one part in a group to a later type.

Our hosts sells it on CD-ROM: Pelican Parts - Product Information: 000-043-400-05-OEM

There's also an interactive program used by the Parts Counter at the stealer, with the same name. This isn't offered for sale.

Tidybuoy · 09:13 PM

Quote:

Originally Posted by 930cabman

Quicksilver,

Thanks for the info, but who/what is PET?

At anytime, you can access the PET catalog directly from the Pelican Parts sight. When looking at any parts page on Pelican, on the upper left of the page is a section "Try Our New Parts Diagram". This is merely a link to the PET. From there, choose your car and year (i.e., 911 944, etc). This will give you diagrams of every single section of the car in great detail - it's the factory parts manual. I use this before any project on my car because it has great diagrams.

Also, if you need to buy a part but don't know what it's called....find it in PET and then enter the part number on Pelican Parts.

You can also access it directly by clicking this link:
Porsche Classic Genuine Parts Catalogue - Classic Genuine Parts & Literature - Porsche Classic - Dr. Ing. h.c. F. Porsche AG

Vern.

930cabman · 10-01-2012, 02:48 AM

Thanks for the help guys, I may move the pump to the front if the change is not that difficult.

BoxsterGT · 10-01-2012, 12:39 PM

930cabman-

I am curious as to what you have for tunnel lines. Are they white or brown nylon as these posted by JeremyD ?.........

Porsche started using these in model year 1974. They were plain tubes without any ferrules or beads to retain the hose. Porsche got away with this for a while, as a rear pump required only low pressures on the suction & return lines in the tunnel.

Some time later between 1975 and the SC models in 1978 they relocated the fuel pump up front and went to black Polyamid tube that used permanent one-way fittings and crimped hoses. The black Polyamid tube seems to last forever, and is now used worldwide by most auto manufacturers. The only issue for the 911 that developed over time was the aging & subsequent failure of the rubber fuel hoses themselves.

If you have the white/brown tunnel lines, NOW is the time to get them out. Lots of posts re: the cracked and split and crumbling nylon tubes in the mid-70's 911 models.

Lots of posts on replacing these lines. Its not technically difficult, just time consuming and a bit of a pain to do.

Let us know what you find.

Len

930cabman · 10-01-2012, 04:52 PM

Len,

I have not disassembled anything yet, but my 1975 911S has two braided hoses that run from the tank to the tunnel, secured with hose clamps at each end. It appears the "metal tubes" in the pic as posted are copper? All things equal I will probably mount the new pump in the stock location.

BoxsterGT · 10-01-2012, 05:31 PM

Apparently the original nylon tubes have been replaced w copper tubing. How are the hoses connected? Are there any ferrules or has the hose been slipped over the copper tube & clamped? OK as long as you keep the fuel pump at the rear.

Once you try to move the pump up front, you need the correct tunnel tubes and Hi-pressure fuel injection hose & fittings. These will be capable of 100 psi or more.

Len