Help me get fuel into 1975 1.8 L jetronic, 1975 1.8 L type fuel problems Options

[Oregon74]

Hello everyone. This is my first 914 world post and ask for help.

I am trying to get fuel into the L jetronic system on this 1975 1.8. I have power to the fuel pump- put in a new fuel injected type fuel pump, new fuel filter. When I put power on I can hear the pump gasping. It is loud and sounds like it is not getting enough fuel, however the fuel from the tank flows in just fine (I've checked- and rechecked).

So I think it is not building pressure in the system. So I've followed the lines around the engine to what I think is the pressure regulator. In the manual I have the pressure regulator has an adjustment on it. The one in this car doesn't. I can't find anywhere where there might be an adjustment.

Please someone guide me. The car appears to have new fuel lines and I'm told it ran once before until the fuel pump quit. It should have been plug and play.

A few more facts: Its got fresh gas. I don't think it has run in about 8 years. Stored inside- I was told. Clean car really. The owner died and his widow has asked for a hand.

I put a fresh battery in to.

Thanks in advance.

Jason
Central Point Oregon

[Dave_Darling]

How is the pump hooked up? Should be from the outlet on the tank (I forget which fitting that is, sorry!) to the filter to the pump, and from there back to the engine bay.

Unhook the fuel-filter-to-pump hose from the pump. Any fuel coming through it? If not, you may have found the problem.

Unhook the fuel-pump-to-engine hose from the pump. Force the pump to run. Any fuel coming out? If not, you definitely have found a problem.

Are the power and ground wires hooked to the correct places on the pump? IIRC, the pump will try to run backwards if you swap them. Which doesn't work that well, predictably.

--DD

[Oregon74]

How is the pump hooked up? Should be from the outlet on the tank (I forget which fitting that is, sorry!) to the filter to the pump, and from there back to the engine bay.

Unhook the fuel-filter-to-pump hose from the pump. Any fuel coming through it? If not, you may have found the problem.

Unhook the fuel-pump-to-engine hose from the pump. Force the pump to run. Any fuel coming out? If not, you definitely have found a problem.

Are the power and ground wires hooked to the correct places on the pump? IIRC, the pump will try to run backwards if you swap them. Which doesn't work that well, predictably.

--DD

I'll look, but I think I've got all that right so far. Thanks DD

[timothy_nd28]

The fuel reg is non adjustable on this car. Also, the fuel pump is somewhat loud, especially when air is present in the fuel lines. A fuel pressure gauge is an excellent tool to have in your garage. It will be hard to tell if anything is wrong at this point, without hooking up a pressure gauge.

How are you applying power to this pump? Are you deflecting the airflow meter flap to activate the pump, or are you hardwiring power to this pump?

[Black22]

The fuel reg is non adjustable on this car. Also, the fuel pump is somewhat loud, especially when air is present in the fuel lines. A fuel pressure gauge is an excellent tool to have in your garage. It will be hard to tell if anything is wrong at this point, without hooking up a pressure gauge.

How are you applying power to this pump? Are you deflecting the airflow meter flap to activate the pump, or are you hardwiring power to this pump?

I was hoping you would chime in Tim! (IMG:style_emoticons/default/first.gif)

Oregon74...listen to what timothy_nd28 say and take notes, he (along with others here) helped me through my L-jet troubles.

You are in good hands.

[wrightee]

Please someone guide me. The car appears to have new fuel lines and I'm told it ran once before until the fuel pump quit. It should have been plug and play.

A few more facts: Its got fresh gas. I don't think it has run in about 8 years. Stored inside- I was told. Clean car really. The owner died and his widow has asked for a hand.

I put a fresh battery in to.

Thanks in advance.

Jason
Central Point Oregon

Are all of the fuel lines new? (including the ones on the front coming to and from the fuel tank)? I recently got mine started with Tim's help, but the first issue I had was with these lines and the fuel strainer sock in the tank. They were all gunked up from sitting. I had some fuel come through the line when I removed the fuel pump, but it was not a free flow. I'd recommend checking at the source 1st, then work your way back, and follow Tim's advice!

[McMark]

(IMG:style_emoticons/default/agree.gif) with Dave.

It's not uncommon for the pressure line and the return line to get flipped.

[Cupomeat]

I find that these pumps are only loud for three possible reasons;
1. Your pump is about to die (unlikely here as it is new)
2. Your pump is priming and getting the air out (This lasts seconds at worst case)
3. You have a restriction on the suction side. (Causes a real noise from the pump and poor pressure)

To me it is likely #3 as these pumps are poor at sucking and very good at building pressure.

Check your feed lines for a kink or other restriction.

Pull the pump out of the firewall (front) and try it with the lines as straight as possible. I once pinched the feed line between the tank seam and the body which caused poor pump performance and serious noise.

If I let pressure build I could get the car to run for a bit, but the line pressure would slowly fall to 0psi and the car would obviously die.

1.8l L-Jets are VERY reliable once you get it sorted, so don't worry

[Oregon74]

The fuel reg is non adjustable on this car. Also, the fuel pump is somewhat loud, especially when air is present in the fuel lines. A fuel pressure gauge is an excellent tool to have in your garage. It will be hard to tell if anything is wrong at this point, without hooking up a pressure gauge.

How are you applying power to this pump? Are you deflecting the airflow meter flap to activate the pump, or are you hardwiring power to this pump?

Thanks for the help Tim.

Power is just from the wiring already present when I took on this project.

Not sure how to deflect the airflow meter flap.

Thanks again for the help

JAA

[Oregon74]

I find that these pumps are only loud for three possible reasons;
1. Your pump is about to die (unlikely here as it is new)
2. Your pump is priming and getting the air out (This lasts seconds at worst case)
3. You have a restriction on the suction side. (Causes a real noise from the pump and poor pressure)

To me it is likely #3 as these pumps are poor at sucking and very good at building pressure.

Check your feed lines for a kink or other restriction.

Pull the pump out of the firewall (front) and try it with the lines as straight as possible. I once pinched the feed line between the tank seam and the body which caused poor pump performance and serious noise.

If I let pressure build I could get the car to run for a bit, but the line pressure would slowly fall to 0psi and the car would obviously die.

1.8l L-Jets are VERY reliable once you get it sorted, so don't worry

I'm thinking about pulling the tank and following everything closely. If I can get off the phone early enough Thursday I'll jump in. I did buy a fuel pressure gauge today.

Thanks.

JAA

[Black22]

The fuel reg is non adjustable on this car. Also, the fuel pump is somewhat loud, especially when air is present in the fuel lines. A fuel pressure gauge is an excellent tool to have in your garage. It will be hard to tell if anything is wrong at this point, without hooking up a pressure gauge.

How are you applying power to this pump? Are you deflecting the airflow meter flap to activate the pump, or are you hardwiring power to this pump?

Not sure how to deflect the airflow meter flap.

From the throttle body side you can do it with your finger or pencil. Same for the air filter side.

[timothy_nd28]

A fuel pressure gauge is an excellent tool to have, glad you purchased one. Towards this fuel pump noise, I'm still confused. Do you hear the fuel pump when you turn the ignition key switch to the on position? Or can you hear this fuel pump thru the noise while cranking the engine?

[Oregon74]

A fuel pressure gauge is an excellent tool to have, glad you purchased one. Towards this fuel pump noise, I'm still confused. Do you hear the fuel pump when you turn the ignition key switch to the on position? Or can you hear this fuel pump thru the noise while cranking the engine?

As soon as I connect positive power to the battery the noise starts. The key is not even turned on.

[timothy_nd28]

That doesn't sound good. Sounds like your dual relay is stuck on. Try pulling the dual relay, then reattaching the battery cable. Hopefully you'll have no pump action.

[Valy]

The pump should only be on when engine runs or starts. If it always runs then the wiring is wrong, the AFM door is not closing, dual relay is bad or the ECU is dead (quite rare).
A fuel pressure gauge will help debug the pressure regulator.
However, I bet that after 8 years in storage, the injectors are stuck.

[Oregon74]

That doesn't sound good. Sounds like your dual relay is stuck on. Try pulling the dual relay, then reattaching the battery cable. Hopefully you'll have no pump action.

Thanks for this. The dual relay on this car doesn't look right. One one set of wires are going to it. I assume there should be two-one for each side. Is that correct? Do you have a picture? JAA

[timothy_nd28]

[timothy_nd28]

If your 914 keys are sitting on the kitchen counter, and the fuel pump turns on by simply attaching the positive battery cable to the battery, it can only be one of 2 things.

Someone ran a wire straight from your battery to your fuel pump. I find this very unlikely.
Since you stated that the keys are not in the ignition, and your connecting the battery and the fuel pump turns on, makes me believe that part of your dual relay is stuck in the closed position.
Even if the AFM fuel contacts were in the closed position, it wouldn't power up the fuel pump, unless the ignition key was "on".

[Oregon74]

The pump should only be on when engine runs or starts. If it always runs then the wiring is wrong, the AFM door is not closing, dual relay is bad or the ECU is dead (quite rare).
A fuel pressure gauge will help debug the pressure regulator.
However, I bet that after 8 years in storage, the injectors are stuck.

argh- so the plot thickens with the enclosed photo. I have tried the dual relay (one in the car and one I found in a pile of parts on the floor with the car)- tried wiring on both sides too.

The pump runs.

I disconnected the dual relay and pump runs.

One of the connecters I believe that goes inside the dual relay was wired as shown in the picture. Why would someone have done this?

If I disconnect the dual relay and leave this yellow wire in as shown on this picture, the pump runs without the key turned.

What is going on here?

Help my new 914 World Friends.

[Oregon74]

If your 914 keys are sitting on the kitchen counter, and the fuel pump turns on by simply attaching the positive battery cable to the battery, it can only be one of 2 things.

Someone ran a wire straight from your battery to your fuel pump. I find this very unlikely.
Since you stated that the keys are not in the ignition, and your connecting the battery and the fuel pump turns on, makes me believe that part of your dual relay is stuck in the closed position.
Even if the AFM fuel contacts were in the closed position, it wouldn't power up the fuel pump, unless the ignition key was "on".

Tim-
Your posts have been so helpful. I hope you have a minute to see the picture I just added to the topic.

Thanks

JAA