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

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

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!

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.

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!

with Dave.

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

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

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

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

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

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.

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.

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.

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

Click to view attachment

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".

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.

Click to view attachment Click to view attachment

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

I'll reply later tonight, I have Bio Statistics class in 20 mins.

The dual relay could of been jumped out for various reasons, but for now remove that jumper wire.
That jumper was most likely jumping 86c to 88d, which is switched ignition 12vdc power on pin 86c and 88d is the fuel pump pin. The problem I have with this setup would be running fuel pump current thru the ignition switch. The ignition switch will most likely fail before too long by running high current thru its contacts. It's far better for the ignition switch to drive a small coil, versus a power hungry fuel pump.
So, with that jumper removed, look at the 2 square connectors that plug into the double relay. Inspect the pins within the connector for corrosion, also make sure the pins are seated within the plastic molex connector.

Next, locate your Air Flow Meter, and remove the flat electrical connector. Now study the pins on the AFM. You will be looking for pin 36 and pin 39. After finding these 2 pins, probe these 2 pins with your multimeter (set for resistance). Initially, you will see a reading of OL or infinity on the meter. Next, if you remove the air filter, you can sneak a screw driver inside to push a metal flap inside the AFM. With an extra set of hands, one person measure the resistance on pin 36 and pin 39, while the other person pushes on the flap. With the flap deflected, you should read close to 0 ohms.

Next, inspect the AFM flap, it should move freely and spring back. If your 914 backfired, due to a vacuum leak, this can cause the AFM flap to warp. If the flap warps, it won't move and will hang up.

Now set your multimeter to the DC voltage setting and reinstall the flat electrical connector back on the AFM, and then turn your attention back to the 2 connectors that plug into your dual relay. (make sure the dual relay isn't installed and that jumper has been removed)
Your black meter lead, find a place to ground it somewhere on the battery or chassis. Find pin 86a on your connector (not the dual relay), and insert your red meter lead. Turn the ignition on, you should have 0 volts dc, however if you turn the key to the "start" position, you should see 12vdc. You may need someone to help you turn the key while your watching the multimeter.

Next, find 86b on the connector, and put your red meter lead in that slot. With the ignition on (not start), you should be seeing 0vdc. Reach over and nudge that AFM flap (make sure the connector on the AFM is reinstalled). As you move the AFM flap, you should see 12vdc.

This is a good start, try this and let us know what you get.

Minor screw up, that last test pertaining to you testing pin 86b for voltage. You will not see voltage while performing this test, with the dual relay not inserted.

So, before probing pin 86b for voltage, I'll need you to build a small jumper wire. Attach one side of the jumper wire to the positive side of the battery. The other side of the jumper needs to go in slot 88a. After adding this temporary jumper, probe pin 86b for voltage when you deflect the AFM flap. Be certain that 86b has 0 voltage when the AFM flap is at its resting state.

sorry for the mix up.

Thanks so much. I'll print this out and report back. Can't thank you enough

JAA

Your welcome and it's my pleasure! I know we have deviated from your original problem, but what you have found needs to be fixed pronto.
Here are some pictures from the Ljet manual to help aid you tomorrow. One last thing, when testing with the ignition switch turned to the "on" position, be mindful to not leave it on too long. You can ruin your points or your pointless module if you have one. It may be safer to temporarily remove the negative wire from your distributor to the ignition coil.
Click to view attachment
your Airflow meter

Click to view attachment
this is the pinout for the connector that plugs into the AFM

Click to view attachment
The pinout for the double relay or dual relay.

Anyone here wishing to have a PDF of the original VW L-jet troubleshooting manual should send me a request for one. Warning!: It's a large file and you MUST send me an e-mail address that can/will accept it. You get ONE shot at it, 'cause I don't have the time to waste making multiple efforts to send it to you. Send requests to trannysocket (at) gmail.com. (note the address is spamproofed to some extent, so fix it for use).

The Cap'n

I can't believe how helpful everyone here is. I work in public service and let me tell you America would be better if politicians were like the folks on 914 world helping me.

JAA

I'd love the PDF
jallmand@mac.com

Here's a nice write-up on how the dual relay works: http://www.ratwell.com/technical/DoubleRelay.html

Hello everyone---- this has been great and I've learned more than I ever expected- or planned on- but I do enjoy it.

So I started digging into the relay issue and it appeared to me that whoever short-wired etc really tinkered around in moved wires all over the place. The more I looked, many leads went nowhere. So I thought I'd try to map it all out. For a non-electrican this has been a task.

I have since learned that Bosch 0 332 514 120 was for the bus.

0 332 514 121 - according to my local import VW cool guy shop is for the 914.

Is he right? I brought it home just incase, but now the wiring diagrams don't seem to jive.

JAA

I'm gonna need some more info on what your seeing. You have wires that are cut? If so, which pin does it correlate to on the dual relay connector? How many wires are we talking about? How about some pictures.

My 1974 1.8l uses the 0 332 514 120 part numbered relay.

I think your guy is wrong?

You can verify this on the Pelican Parts website.

Pictures enclosedClick to view attachment

Click to view attachment Click to view attachmentClick to view attachment

I'm not seeing the many leads going to nowhere as you stated earlier. I maybe see one wire that is frayed or not connected.
Click to view attachment

The black connector plugs into the dual relay, and serves the ignition side. The white connector plugs into the same dual relay, and serves your FI side. The white FI connector looks pretty corroded, you should soak that connector in a glass of Coke for an hour.

The only thing that I can see wrong with that black connector is possibly a missing or frayed wire in that picture (I circled what I think the problem area is in red). Is there a terminal in the black plastic connector housing that happens to have a electrical connector in the slot, but no wire going to it?

If I counted the wires in the schematic correctly, you should have 8 white wires going to the FI connector (white connector) some wires may be doubled up on the same terminal. Whereas the black connector (ignition connector) there should be 5 wires, varying in color. The schematic doesn't show any wires doubled up on the ignition connector, but its possible your 75 914 can be different than the 74 schematic.
I wish I had my 914 here at my house, but I let my brother borrow it for a couple of weeks.
If you have a wire connector in the connector slot that's missing a wire, let me know what pin it is. Look under your dual relay, and you will see tiny numbers. Line up the dual relay with the connector and tell me what pin numbers are missing a wire if any. If you have loose wires that are taped off or not going to anywhere, tell me what color wire it is and the thickness of the wire.
Nonetheless, I don't see anything crying out from your pictures other than a corroded connector, and possible a frayed wire that maybe fell off its terminal.

Tim-

Here is a picture of the relay.
How the left side goes in. Yes, 8 wires. Not all leads connect to the tab on the relay.
The right side how it goes in. Note the brown wire is the fuel pump. Not connected.
Another angle of the right side where the wires go in

All Coke cleaned

black connector, pin 85 should be the brown ground wire

Pin 88d is your fuel pump wire on the black ignition connector. The 88d wire should be red/green,,this drives your fuel pump

Cool Brown is ground

I have yellow to 85 right side of the 3rd pic
88f is that red duallydo thingy someone made

middle of the relay

88b the other end of the red wire
88e empty
88c empty

left side of the relay

86 black wire
88a red and black wire
86b empty

I have wiring diagrams for both the FI and Ignition harnesses available for free download on my website if you need them. They show which wires go to which cavities in the connector housings to help you verify things.

http://bowlsby.net/914/WiringHarnesses/

I don't think that relay will work. Your 121 series relay has no pin 85 by the 88z pin. Where is your 120 series relay?

got it right here

Click to view attachment
Click to view attachment

slight difference between the two, notice how pin 85 the gnd wire is on a different relay

Using the 120 series relay

pin 85 should be brown (ground wire)
pin 88z should be a big red wire (gets power from battery)
pin 86c should be smaller black wire "schematic calls for red/black" (gets power from ign switch (on))
pin 88d should be big black/red stripe wire,,really should be green with red stripe but looks like black/red stripe to me (fuel pump wire)
pin 86a should be yellow wire (gets power from ign switch (start))
pin 88y should be big red wire jumped to 88z

Great- will report back- JAA

Ok Tim-

I follow your instruction to the tee- any let the world know she starts right up. I don't know who you are other than a 914 doctor, but I'd love to buy you lunch. Thanks a million.

No, before you order desert:

I'm laughing at myself now- I push down the accelerator pedal and the cable on the air flow housing side (I almost said carb side- but caught myself) came un buttoned.

For the life of me I can't fiqure out how it connects. If a part came undone, I don't know what I am looking for.

Secondly, she runs nicely for about 20 seconds and shuts down. This might be because for the last two hours I have been trying to fiqure out the cable connect issue. However, when i give it throttle with my hand it still dies.

One major mystery and a fuel pump replaced, now two more.

JAA

It must be a throttle cable bolt- but why did it fall off and I can't find it?

throttle fixed

fires up every time

dies in 20 seconds

Cool,

Try this, pull the connector off of the cold start valve, then try starting the engine. With this connector off, does it even start? If it starts, does it still run for 20 seconds?

If it runs and nothing is different, reconnect the cold start connector.


Try this next, pull off the connector off of the aux air valve, and try starting the engine, same thing as above.

Remember that white connector that plugs into the dual relay. I know you cleaned it, but pull the connector off and on 33 times. This will help provide a better connection.

Towards the throttle cable, did you find the barrell nut that fell off?

If the above 2 steps fail to show any results, grab a can of starting fluid and spray around the vacuum hoses and different parts of the engine, to look for vacuum leaks. Double check your oil filter cap.