Replacement Fuel Pump - What do you do with Third Fuel Line? Options

[ChrisFix]

The fuel pump in my 74 1.8 L-Jet seems to be dead. I plan to pick up the Bosh single inlet/single outlet pump at Napa (Part Number: BSH 69133). The dual relay at the battery checks out good, and when I turn on the ignition, I get a single click from the fuel pump, but no priming/whirring sound - and no fuel delivery. Engine will fire if I squirt a bit of starter fluid in the intake snorkel, then quickly dies.

What exactly do you need to do with the 3rd fuel line on the current pump? I've found a few posts that simple say "convert it to 2-line pump", but I'm out of my depth with knowing what to do that won't compromise the car's, or my, safety. I searched but couldn't find any drawings or pictures of how to route the lines, or what to do with the 3rd line.

Any detailed advice would be welcomed!

Thank you,
Chris

[Cap'n Krusty]

Simply remove the "Y" from the return line, running the piece from the engine directly to the piece to the tank. Rather than splice it, it's a good idea to replace the 2 old hoses with one new one.

The Cap'n

[dlee6204]

FYI With L-Jet, when you turn the ignition on, the pump will not prime... That is only on djet.

The fuel pump only comes on when cranking and running with LJet. If you turn your ignition on and then operate the flap inside the afm, you should hear the pump run.

[timothy_nd28]

(IMG:style_emoticons/default/agree.gif)

[ChrisFix]

Thank you for your help.

When the flap is moved in the AFM, I just get a click from the dual relay, but no fuel pump activity.

I've ordered a new dual relay to test (or as a spare if current is indeed good as I believe).

What type of fuel line do I need to buy to replace the section from the engine directly to the piece at the tank? Is the correct type available at a FLAPS or is it a special order affair?

Thanks again for your help and support...

[Cap'n Krusty]

Be aware the replacement relays available today may not be plug 'n play. Once you hack on it to make it fit, it's yours. BTW, there were more than 1 double relay, and they're functionally different. Look at the relay diagram printed (or embossed) on the side. Before you do anything else, put a test light on the FP power wire on the relay and see if it lights up when you activate the flap. Next, make the same test at the pump connection. Test the ground there at the same time.

The Cap'n

[ChrisFix]

Be aware the replacement relays available today may not be plug 'n play. Once you hack on it to make it fit, it's yours. BTW, there were more than 1 double relay, and they're functionally different. Look at the relay diagram printed (or embossed) on the side. Before you do anything else, put a test light on the FP power wire on the relay and see if it lights up when you activate the flap. Next, make the same test at the pump connection. Test the ground there at the same time.

The Cap'n

Thanks, I'll take a look at that tomorrow when I'm home. I purchased the relay with 11 pins, like the one that I have on my car (they sell one with 13 pins as well). This is what I bought:

http://www.autohausaz.com/search/product.a...%20Pump%20Relay

Hopefully, it is a direct replacement. It won't arrive until early next week.

Also, do you know what size & type (and how much) of fuel line do I need to get if I put in a new Bosch fuel pump and bypass the Y connector?

[ChrisFix]

Got under the car this afternoon, and there is power and ground to the fuel pump (with ignition on and AFM flap activated)...just no pumping. Bought the generic "Airtex E8445 Universal Replacement In-Line Electric Fuel Pump for Fuel Injected Systems" for $70 at my FLAPS, and tested it briefly without hooking up the fuel lines. It fired right up as soon as power was applied.

So, just a dead 40 year old fuel pump!

I do need to redo all my fuel lines. They are 100% original and very brittle. The line from the fuel filter is kinked, and the clear lines are very hard. So this looks like the opportunity (or challenge) of pulling the fuel tank, cleaning it, replacing the fuel sock, and all the lines back to the engine. Should be fun?!

[brant]

I hate to tell you this.
But you should consider replacing the yellowed plastic hard lines through the tunnel. If the are original

Metal is the preferred way. And easier with the engine out

[RJMII]

74 has the fuel pump up front?

I have replacement fuel pump in mine. (Not exactly a 1.8 L-Jet)

I pulled fuel from the tank to the walbro-xxx; then on the pressure side I have a 'T'. One one part of the T is a modern plastic High Pressure fuel pump fuel line that goes through the tunnel, and to the engine. On the other part of the T is the fuel pressure regulator. The pressure side goes in on the side, and the relief side goes out the bottom, and back to the tank.

I just have the one fuel line through the car now, and it is modern stuff that doesn't break down like the older plastic ones.

Not sure if this helps for the 1.8 setup you have, but it works for what I'm running. :-)

[ChrisFix]

I hate to tell you this.
But you should consider replacing the yellowed plastic hard lines through the tunnel. If the are original

Metal is the preferred way. And easier with the engine out

Yes, I agree....hence the "opportunity and challenge" aspect of going through the fuel system...but it is obviously time for my 914...

I spoke with Chris at Tangerine racing, and figured out what I'll need. I'll be buying his metal tunnel lines.

[ChrisFix]

74 has the fuel pump up front?

I have replacement fuel pump in mine. (Not exactly a 1.8 L-Jet)

I pulled fuel from the tank to the walbro-xxx; then on the pressure side I have a 'T'. One one part of the T is a modern plastic High Pressure fuel pump fuel line that goes through the tunnel, and to the engine. On the other part of the T is the fuel pressure regulator. The pressure side goes in on the side, and the relief side goes out the bottom, and back to the tank.

I just have the one fuel line through the car now, and it is modern stuff that doesn't break down like the older plastic ones.

Not sure if this helps for the 1.8 setup you have, but it works for what I'm running. :-)

74 1.8 has the fuel pump under the car tucked up beside the passenger side longitudinal - right beside the heat exchanger. The electrical connector was scorched on the outside!

I'm looking at replacing the tunnel lines with metal. What type of plastic lines are you using? Sounds like they might be less expensive and easier to install?

[kmwvmarip]

I replaced mine with the engine in and it was not bad at all. A good friend can help nudge it through the tunnel.

I do however wish that I had the engine out for convenience when replacing the vacuum hoses and fuel lines in the engine compartment. Live and learn. In the end it all stayed in the car.

I swear that the zee Churmans had a race of monkeys with a few extra wrist joints to do some of the things they had to do.

[ClayPerrine]

Consider moving the fuel pump up front under the tank when you do the install. Also, I used a ford carburetor fuel filter on the intake side of the pump to protect it from crud in the tank.

Tangerine racing lines are great. I have installed close to a dozen kits now, and they fit perfectly every time.

[ChrisFix]

Consider moving the fuel pump up front under the tank when you do the install. Also, I used a ford carburetor fuel filter on the intake side of the pump to protect it from crud in the tank.

Tangerine racing lines are great. I have installed close to a dozen kits now, and they fit perfectly every time.

After seeing the heat marks on the electrical connector for the fuel pump, I'm inclined to believe getting it away from that heat is a good idea.

When you say "under the tank", is this the location the 75-76 models used, or is there an alternate location that doesn't require the specific cover plate Porsche used?

[ChrisFix]

I replaced mine with the engine in and it was not bad at all. A good friend can help nudge it through the tunnel.

I do however wish that I had the engine out for convenience when replacing the vacuum hoses and fuel lines in the engine compartment. Live and learn. In the end it all stayed in the car.

I swear that the zee Churmans had a race of monkeys with a few extra wrist joints to do some of the things they had to do.

I think I'm going to drop the engine at the same time...I have very leaky push rod tubes that need to be addressed, and a thorough going over is not out of order at this point. To my knowledge, the engine has never been out of this car (only has 43K miles), but after 40 years, there are plenty of things that could use some TLC. And with the engine out, I can replace all the engine/injector fuel lines and vacuum hoses very easily.

[JawjaPorsche]

No need to move your pump to the front, just relocate to the firewall. I moved mine 15 years ago and never had a problem. The original location is just too damn hot for a fuel pump.

Chris at Tangerine Racing is great. Got my steel tunnel lines from him. Get new rubber grommets too for firewall. Here is link to video to install lines: https://www.youtube.com/watch?v=hxFRQTWLetw

There are two plastic fuel lines that go from fuel pump to engine bay that probably needs to be replaced too. Chris has those too. Replace fuel sock in tank too.

I had to get a fuel line adapter piece from Chris too.

Good Luck!

[brant]

Under the fuel tank (above the pan) is the front relocation spot.

On a track car we always moved weight forward and down.
Plus the pump gets to push instead of pull.

[ClayPerrine]

When you say "under the tank", is this the location the 75-76 models used, or is there an alternate location that doesn't require the specific cover plate Porsche used?

I have the fuel pump under the tank in the well by the tank connections. The Airtex E8445 pump is small enough to mount there without interfering with anything else. Plus, I have a Ford carburetor fuel filter on the inlet side, both to make sure the pump doesn't get crud in it, and to use as an adapter to the suction side fitting on the tank.

Lots of people put it in the steering rack well so they can get to it in case of failure. Frankly, I never had a problem with pulling the tank to replace the pump. It's not that bad of a job, and you don't have to push the gas back uphill to the lines.

[ChrisFix]

Lots of great information and suggestions....Thank you all!!