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

[emerygt350]

So, was running fine, going to double check my timing, wouldn't restart (tried, but couldn't keep running). No pump sound and no pressure on the gauge (I love you, fuel pressure gauge). Whacked the pump with a screwdriver handle, nothing. Pushed it into the garage, figured I would give it one last listen in the quiet, heard a little bit of something, then a little grumble from the pump and I had pressure again. Started up just fine.

To me that says fuel pump, not relay. Any other experienced folk have some wisdom?

I need to move my pump up front anyway but I was planning on keeping the original.


now that I am thinking about it, it did struggle to start earlier in the day as well but cleared up.

Car sat for a couple months during the winter.

[ClayPerrine]

So, was running fine, going to double check my timing, wouldn't restart (tried, but couldn't keep running). No pump sound and no pressure on the gauge (I love you, fuel pressure gauge). Whacked the pump with a screwdriver handle, nothing. Pushed it into the garage, figured I would give it one last listen in the quiet, heard a little bit of something, then a little grumble from the pump and I had pressure again. Started up just fine.

To me that says fuel pump, not relay. Any other experienced folk have some wisdom?

I need to move my pump up front anyway but I was planning on keeping the original.


now that I am thinking about it, it did struggle to start earlier in the day as well but cleared up.

Car sat for a couple months during the winter.

That sounds like a pump to me. Move it up front, and replace it with an Aritex E-8445 pump. It is functionally equivalent to a 75-76 pump, but not physically identical. And it is available at your FLAPS.

Clay

[Superhawk996]

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)

[emerygt350]

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.

[emerygt350]

or maybe i will do nothing and call it my quantum anti-theft device...

[windforfun]

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.

Such is life with a 50 year old car. They can be a PITA.

[emerygt350]

I guess the good thing is that with current gas prices, running tank empty so I can pull it is almost second nature. Keeping the car running long enough might be harder.

[ClayPerrine]

I guess the good thing is that with current gas prices, running tank empty so I can pull it is almost second nature. Keeping the car running long enough might be harder.

(IMG:style_emoticons/default/idea.gif)

So buy the new electric pump like I suggested. Hook some hoses to it, and some wires with alligator clips on the other end, and use it to transfer the gas out of the 914 tank into some other vehicle.



I actually keep a spare pump in my garage setup for this task. And if the pump fails on one of the 914s, then I have a spare already available.


Clay

[Superhawk996]

The screwdriver was there in my hand. It was made for whacking.

So true. (IMG:style_emoticons/default/grouphug.gif) Probably would have been my 1st instinct too. Then the DMM (IMG:style_emoticons/default/happy11.gif)

[DRPHIL914]

So, was running fine, going to double check my timing, wouldn't restart (tried, but couldn't keep running). No pump sound and no pressure on the gauge (I love you, fuel pressure gauge). Whacked the pump with a screwdriver handle, nothing. Pushed it into the garage, figured I would give it one last listen in the quiet, heard a little bit of something, then a little grumble from the pump and I had pressure again. Started up just fine.

To me that says fuel pump, not relay. Any other experienced folk have some wisdom?

I need to move my pump up front anyway but I was planning on keeping the original.


now that I am thinking about it, it did struggle to start earlier in the day as well but cleared up.

Car sat for a couple months during the winter.

the last time this happened to me it was a short on the rear relay board, the FI circuit was shorting out. So, it could be fuel pump relay or the board. It was hard to diagnose and first because when i took the board out to test it with the almighty DMM all circuits tested fine, no loss of continuity, but when in the car, just the movement of the car or the vibration and it would stop. finally figured it out by accident ,happened to push down on the relay whic was enough pressure to make good contact and the pump primed. new board, no issue.

just might be your issue, its not always the pump,

[GregAmy]

Any time someone discusses a fuel pump prob, my first recommendation is to make a jumper wire for the relay.

I chased my tail on a "fuel pump" prob before it was finally isolated to the relay/board.

There's so many ongoing issues with relays and the board that "electrical" is always my initial go-to. Get that possibility eliminated first.

[emerygt350]

Thanks guys, yeah, that will be my job this afternoon. I will see about bypassing that relay.

[emerygt350]

Hmmm... Power to the pump and no signs of issues. Set my timing, drive around loving the new found peppiness and exhaust growl. Got it nice and hot, turned it off, pump sounded fine, started up without issue.

Would a dying pump recover like that or does that seem more like a relay behavior? In my experience pumps would just kind of poop the bed or at least make terrible noises.

[Bartlett 914]

Hmmm... Power to the pump and no signs of issues. Set my timing, drive around loving the new found peppiness and exhaust growl. Got it nice and hot, turned it off, pump sounded fine, started up without issue.

Would a dying pump recover like that or does that seem more like a relay behavior? In my experience pumps would just kind of poop the bed or at least make terrible noises.

This is always the problem with intermittent issues. The FI circuit will shut off the pump if the car stops running. Jumping the fuel pump relay will eliminate the FI electronics as the cause. Then if there is no pressure, you can measure to insure that that you have voltage at the pump. Use a DMM to make sure and do not assume because the relay is bypassed that there is voltage there. It could be a bad connection with the supply and or ground connections. Once measured that you have voltage at the pump and no pressure (pump not running), You will know if the pump is bad or not. Go from there

[emerygt350]

But for that it has to be in a failed state. I wonder about checking the draw on the circuit there. If the pump is failing I bet it is drawing more or less amps than normal. Would that work?

[wonkipop]

Hmmm... Power to the pump and no signs of issues. Set my timing, drive around loving the new found peppiness and exhaust growl. Got it nice and hot, turned it off, pump sounded fine, started up without issue.

Would a dying pump recover like that or does that seem more like a relay behavior? In my experience pumps would just kind of poop the bed or at least make terrible noises.

a dead pump usually does not recover.
but i suppose there is always the exception.

the typical failure mode is internal failure.
brushes wear down and jamb up commutator.

take mr. p's advice. change it anyway.
use the pump in the car to do the fuel transfer trick.
i'm going to follow the tip.
fuel prices are f'n nuts here.
i drove up country a couple of weekends ago in the big citroen.
first time in years i was touching the go pedal with a feather and driving under the speed limit. got into drafting semis.

[SteveL]

If you move the pump to the front, isn't it a best practice to also replace the tunnel fuel lines with stainless? The factory lines were not spec'd to be under 35psi, correct? I have my replacement 2 port fuel pump mounted on the engine firewall for this reason.

[wonkipop]

If you move the pump to the front, isn't it a best practice to also replace the tunnel fuel lines with stainless? The factory lines were not spec'd to be under 35psi, correct? I have my replacement 2 port fuel pump mounted on the engine firewall for this reason.

yes

i've left mine on the firewall for same reason.
but did replace the internal fuel lines with mild steel tubing.
discovered that original lines were not only brittle at exposed end but also for a good 6 or so inches back into the tunnel. the rest of the fuel lines were in remarkable condition.

what i have noticed is modern design turbine style two port does not like that location nearer engine as much as the old original pump.
suffer more in hot weather. i've rebuilt the original and a spare of the original to go back in.

think if i was committing to an inline long term i would go front end location.
+ steel pipes through cabin.
stainless makes me nervous. its brittle under stress.
thinking worst case scenario of a serious collision.
pray it never happens to me or anyone else in their 914.
but ss kits are a brilliant convenience.
i had to make my own anyway, differences due to rhd.
discovered its not that difficult to make your own lines if you have time and patience.

[emerygt350]

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?

[Rob-O]

Lines for the ‘75 and ‘76 were made for pressure since the pumps were in the front of the car on those years. But even then it would be wise to replace with stainless.