fuel pump fail, I think it's the pump... Options

[wonkipop]

Interesting Wonkipop, I hadn't really considered building my own lines in the tunnel. I had forgotten about that pressure issue too. Just worried about reliability now. When you guys say you put it on the firewall, what do you mean? Where did you put it exactly? Filter too?

by firewall i mean in the original position for 74.
which is the cabin/engine wall area.
strictly speaking its mounted off the metal panel off the edge off the longitudinal.
jambed right up in that corner underneath to get it as far from radiant heat sources as factory could. think earlier cars than 74 had it mounted on rear wall of cabin, engine side.

i've gpt a standard old style plastic cube filter pre pump. (have a stash of those in a box i bought 30 years ago). clipping still into the clips in that area the factory fitted.
its fine because that line is still gravity feed (or weak suction take your pick) from the tank.

after the pump and up in the engine bay i have a full flow high pressure filter (larger metal cylinder type) and i mounted that off the bracket that the decel valve bolts to.
thats not standard and i did it for two reasons.
1) i probably got the last set of original bosch injectors i will ever find. though thanks to mr. p i know now the datsun and other ones i could get. but i wanted to protect those injectors.
2) modern pumps when they spit their internal guts can put it through the fuel lines.
interestingly having pulled apart two original three port pumps those pumps i believe would never blow their guts into the fuel system. the way they are built and engineered.
you would have to be really unlucky. probably why porsche and vw left off any kind of high pressure filter post pump.

post above by @Rob-O brings up interesting point.
think possibly fuel lines on 75 on had different diams due to pressure as well.
but really don't know.
i imagine the ss line kits with whatever diams they are work just fine as folks seem to do them with pump up front and it all works.

(IMG:style_emoticons/default/beerchug.gif)

i've always wondered how many pre 75 914s are out there as ticking time bombs with 80s front pump conversions but still have low pressure clear plastic fuel lines through cabin.

(IMG:style_emoticons/default/blink.gif)

EDIT
making your own fuel lines is fun.
but you don't want to be on a cold garage floor trying to endlessly fit them trial and error.
i think it took me about 3 days.
but i had to take a lot of breaks, walk away and come back.
i also had a person assist me at crucial times when i was actually test fitting to guide the upper end through the upper end of tunnel.
you get all the curves and kinks right for the tunnel and when they fit well,
you pull them out and do the last set of tight and tricky bends out of firewall and into engine area.
thats the fun bit when you go back to do the final fit.
intense.
you need the car well up in the air and take the rhs rear wheel off.
and once they are in have about 15 beers to celebrate.
also i found it a good idea to protect with reflective insulation where they travel across rear of cabin.
when you drive the car and stop the magnesium fan shroud is a heat sink and gets real hot and radiates right at those metal lines.
the original plastic lines did not have that problem.
so all the vapor lock problems get intensified without proper attention to remedies.

[Aerostatwv]

If you want to have the factory pump rebuilt, these folks can do it: https://fuelinjectioncorp.com/
They rebuilt mine and offer an 18 month warranty on their work.
Good Luck!
Chris

[Van B]

Not trying to be an (IMG:style_emoticons/default/bootyshake.gif) Had you tested with a DMM for power at the fuel pump rather than (IMG:style_emoticons/default/smash.gif) with a screwdriver you would have data and facts to work with and we wouldn't be guessing. (IMG:style_emoticons/default/poke.gif)

At least you had the fuel gauge which is data about the fuel pump output (i.e. fuel pressure). (IMG:style_emoticons/default/smilie_pokal.gif)
What we don't know is that the fuel pump had input (12v & free-flowing fuel at the pump inlet)

Yeah yeah yeah... that would require me to go downstairs into the basement, find the multi meter, back up into the yard, yadda yadda yadda, look up that thread on fuel pump trouble shooting, take the top off the relay board, figure out which way is the front of the car...
blah blah blah. The screwdriver was there in my hand. It was made for whacking.

It has fuel, it is the question of power that I will have to pursue... maybe even with your damn multimeter.

I’m not gonna lie @Superhawk996 emery makes a convincing case.

As a military man, I would take it one step further and remove that pump from command due to loss of confidence in its ability to run fuel delivery operations.

Leaving it there sets a bad example for the other parts on the car and the next thing you know, they’ll stop working as well! (IMG:style_emoticons/default/blink.gif)

[wonkipop]

Not trying to be an (IMG:style_emoticons/default/bootyshake.gif) Had you tested with a DMM for power at the fuel pump rather than (IMG:style_emoticons/default/smash.gif) with a screwdriver you would have data and facts to work with and we wouldn't be guessing. (IMG:style_emoticons/default/poke.gif)

At least you had the fuel gauge which is data about the fuel pump output (i.e. fuel pressure). (IMG:style_emoticons/default/smilie_pokal.gif)
What we don't know is that the fuel pump had input (12v & free-flowing fuel at the pump inlet)

Yeah yeah yeah... that would require me to go downstairs into the basement, find the multi meter, back up into the yard, yadda yadda yadda, look up that thread on fuel pump trouble shooting, take the top off the relay board, figure out which way is the front of the car...
blah blah blah. The screwdriver was there in my hand. It was made for whacking.

It has fuel, it is the question of power that I will have to pursue... maybe even with your damn multimeter.

I’m not gonna lie @Superhawk996 emery makes a convincing case.

As a military man, I would take it one step further and remove that pump from command due to loss of confidence in its ability to run fuel delivery operations.

Leaving it there sets a bad example for the other parts on the car and the next thing you know, they’ll stop working as well! (IMG:style_emoticons/default/blink.gif)

words like that make me wish the entire world was run by the us military.

i have had the joy of working for the cops here as clients.
i just love chains of command.


......although there is always the possibilty you could strike the potentially insane ECU at the end of all the wires.

[ClayPerrine]

Interesting Wonkipop, I hadn't really considered building my own lines in the tunnel. I had forgotten about that pressure issue too. Just worried about reliability now. When you guys say you put it on the firewall, what do you mean? Where did you put it exactly? Filter too?

Here is a how to do it article I wrote before the kits were available:


http://www.914world.com/specs/tech_fuellines_ss.php

Now I just buy the kits from Tangerine Racing.

Clay

[Superhawk996]

I’m not gonna lie @Superhawk996 emery makes a convincing case.

As a military man, I would take it one step further and remove that pump from command due to loss of confidence in its ability to run fuel delivery operations.

Leaving it there sets a bad example for the other parts on the car and the next thing you know, they’ll stop working as well! (IMG:style_emoticons/default/blink.gif)

(IMG:style_emoticons/default/lol-2.gif)

Ya' all welcome to swap as many parts as your budget affords but the fact remains we don't know if 12V was present and/or whether fuel was flowing freely. The fuel lines under the tank are notorious for kinking and of course the in tank fine mesh fuel filters have been know to get clogged. I guess I don't know for sure but it seems we are discussing an old 3 port pump - rear mounted? Temporary vapor lock?

I know I'm stretching a bit at the mesh sock being temporarily clogged but to say it wasn't is an assumption. I don't normally replace parts on assumptions that I haven't verified.

If anyone makes a good case, it's Clay - buy the new pump to ease draining tanks and then if you need it, you have it and can relocate to the front.

[emerygt350]

For the couple hundred bucks it is worth avoiding the cold garage floor. I am tempted to move it up into the 74 position though. At least if it has issues I can reach it easier.

And I can make an example of it to the rest of the engine.