Fuel Pump Fun?!?!?!?

[aveale]

Well, I am sure this is a rite of passage.

I have been having some serious fuel issues for my 73 2.0.

My original fuel pump (fp) did not leak until i decided to change some of the hoses....

Ordered used replacement from a nice chap in Toronto at Porschapart but it leaked too.

Ordered a new one for a 1975 (?) and up and slid her into place. As all of YOU know, the old pump as 2 Return outlets (D and R) and the new one has one, so I "T'd" everthing together so that it receives fuel from the out port on my new pump.

It does not want to start...occasionally I get some sputters...whereas before it would start at the first crank!!

So, my questions are.....

1- was having everything joined (T'd) together the correct thing to do?

the present set up is - Tank->Filter->FP->two splitters that go to both fuel rails and the fuel return line(?)

2- do i have to prime the blasted thing or any of the lines?
3- how many cranks to get fuel to the injectors? - is it more than 100?
4- has anybody had success with the fuel pump upgrade that they can share?
5- why did I get myself into this?
6- will my wife ever forgive me for spending 40+ hours in the garage sniffing and smelling like gas?

Ahhh life is funny.

Thank you everyone!

T

[Dave at Pelican Parts]

It sounds like you T'd the wrong things together. That may be causing the problem, or it may be incidental.

S == saugen ("suction")
D == druck ("pressure")
R == rückkehr ("return")

So you want to have the tank go to the filter, then to the "S" port. You want to have the "D" port go to the right-side fuel rail, and from there go across to the left-side one, then to the fuel pressure regulator. From there, you go to a T-shaped (or Y-shaped) splitter. One of the arms of the T goes to the "R" port on the pump, the other goes back to the fuel tank again.

See the hose diagrams elsewhere on this site for more details.

--DD

[aveale]

Thanx D,

I will check it out.

it kind of makes sense now !!!?!!

T

[Tidybuoy]

Just my 2 cents worth:

When I moved my fuel pump to the front on my 1974, I used a '76 style pump. At that point, I completely eliminated the "T".

My setup goes: Tank > Filter > input side of FP > input side of fuel rail> back to tank.

I'm not sure which fuel line is the input side of the fuel rail but I just followed the old setup. I believe the "return to tank" side is the side with the pressure regulator (which basically keeps pressure in the lines surrounding the engine).

I did all of this about 2 years ago and I have never had any problems.

Vern

[aveale]

your reply is worth more than 2 cents!

Thanx, and I have a good handle on it now.

T

[BigD9146gt]

Vern, your absolutly right. The pressure regulator is the last stop before the fuel heads on back to the fuel tank.

[Tidybuoy]

While your at it, why not move the pump to the front.

Some of the problems with the "under the battery" location:
1) Fuel gets hot & can cause vapor loc (although I never had this problem)
2) fuel pump can get corroded from battery acid & fuel lines too
3) it's pretty easy to install
4) much easier to change the fuel filter in the future
5) The fuel lines under the battery area will be much neater & cleaner looking.
6) It's really cool.

I managed to get the whole set up from a 1976 donor car & so, I got the factory cover for the front hole that you must cut out. As far as wiring, I got the wire from the '76 but trying to get an orig wire to run thru the orig harness is next to impossible. I eventually tapped into my existing wiring to my old fuel pump. The whole project took a couple of hours.