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Discussion Starter #1
Gas leaked on a broken fuel pump hose and I drained the gas to empty the tank.
I did not replace the hose right away for maybe 3 months and when I finally replaced the hose and filled the tank, the car won't start.
I replaced the fuel pump and still won't start.

I would really appreciate any ideas and recommendations to get the car running again.
 

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1999 E320 - 2012 Porsche Cayman - 2003 S500 -2020 X5 BMW
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are you getting fuel to the /fuel rail injectors? Lots of items in between pump and injector spray
 

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450slc5.0cab 280sl5sp 280se4.5 500se+500slAMG +250seStkW108 350sl4spdX3 500secEuro
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1978? K-jetronic.

Do you have a wire clip next to the fuel distributor? If so, disconnect it to run the fuel pump constantly and press on the air pressure sensor plate to see if there’s pressure and the injectors squeal releasing fuel into the cylinders and intake runners. Don’t let it run too long because it could fill cylinders with open intake ports and you can hydro lock the engine.

Can you elaborate on your issue?

Have you tested to see if you have spark / combustion by putting something combustible into the sensor plate area?
 

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Spark - air- fuel .
 
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Discussion Starter #6
1978? K-jetronic.

Do you have a wire clip next to the fuel distributor? If so, disconnect it to run the fuel pump constantly and press on the air pressure sensor plate to see if there’s pressure and the injectors squeal releasing fuel into the cylinders and intake runners. Don’t let it run too long because it could fill cylinders with open intake ports and you can hydro lock.

Can you elaborate on your issue?

Have you tested to see if you have spark / combustion by putting something combustible into the sensor plate area?
Please be patient with my limited knowledge of mechanics terms because I'm just a beginner on this car. You mentioned wire clip next to the fuel distributor, do you mean an electrical connector? There is an electrical connector in the fuel distributor body. Does the wire clip directly activates the fuel pump without the ignition switch?
There is spark from the coil wire and to the spark plug wires. I sprayed starter fluid in to the air pressure sensor plate but no firing happened. When I pulled out the spark plug, it's wet with gas.
The engine turns but no ignition.
 

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So you are confident that the spark plug wires are getting timed spark to them? Have you also tried grounding a spark plug and connecting it to a spark plug wire to assure it is actually sparking?

Because if you are spraying combustible stuff into the intake (and plugs are wet with fuel), and you have spark, you should get at least a little combustion.

Please be careful not to have exposed spark anywhere near fuel or fuel vapors.
 

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If the plugs are really wet and fouled they need a fresh set. Then make sure you have a strong spark at the plugs.
 

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Discussion Starter #9
So you are confident that the spark plug wires are getting timed spark to them? Have you also tried grounding a spark plug and connecting it to a spark plug wire to assure it is actually sparking?

Because if you are spraying combustible stuff into the intake (and plugs are wet with fuel), and you have spark, you should get at least a little combustion.

Please be careful not to have exposed spark anywhere near fuel or fuel vapors.
I have to get a new battery and grounded a spark plug with the a park plug wire connected. Spark on the spark plug was good and smelled gas on the air intake. Is it possible that the timing was off? Reading a book and timing should be 0 TDC.
 

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Discussion Starter #11
When you turn the key in the ignition, does the fuel pump run?
I did not hear a pump running when I turned the key on the ignition, so I left the key turned on and checked the voltage on the pump terminal. There was 0 voltage, so I went to the fuse box and checked the fuse for the fuel pump (fuse#6). The fuse is good. Does the fuel pump have a cut-off switch after running for a certain time? This is a new fuel pump that I just installed.
 

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Discussion Starter #12
When you turn the key in the ignition, does the fuel pump run?
When you turn the key in the ignition, does the fuel pump run?
I turned the key to the ignition and did not hear the fuel pump running. So I left the key turned on in the ignition and checked the voltage on the fuel pump terminal. It was zero voltage. So I went into the fuse box and checked the fuse for the fuel pump (#6 fuse). The fuse is good. Is there a cutoff switch for the fuel pump to limit the time when it is on after the ignition is turned on?
 

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I turned the key to the ignition and did not hear the fuel pump running. So I left the key turned on in the ignition and checked the voltage on the fuel pump terminal. It was zero voltage. So I went into the fuse box and checked the fuse for the fuel pump (#6 fuse). The fuse is good. Is there a cutoff switch for the fuel pump to limit the time when it is on after the ignition is turned on?
Yes. If you have a plug wire on the passenger side of the distributor, you can unplug it and the pump should run constantly when the key is on I believe.





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Discussion Starter #14
Yes. If you have a plug wire on the passenger side of the distributor, you can unplug it and the pump should run constantly when the key is on I believe.





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I disconnected the plug wire as shown on your photo and turned on the ignition but the fuel pump did not run. I checked the voltage on the terminals and it's zero. I decided to find and check on the F/P relay. It was not clicking when the ignition key is ON. I ordered a new F/P relay which will arrive in 7 days. I'll keep you posted when I install the new relay.
I really appreciate your effort in helping me get the car running again. Do you have any suggestion as to what I can do on the car while waiting for the part?
 

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Fuel pump relay can be jumpered to make the pump run constantly, but it’s VERY important to remember to shut it off quickly because injectors could fill cylinder(s) and hydrolock the motor causing damage.
 

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Fuel pump relay can be jumpered to make the pump run constantly, but it’s VERY important to remember to shut it off quickly because injectors could fill cylinder(s) and hydrolock the motor causing damage.

No joke. I have a friend that bent a rod on a 6.9 from hydrolock.
 

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Have you put 12V directly to the fuel pump to see if it runs? It is not unusual for new, out of the box electrical parts to fail. Very frustrating to your diagnostic efforts.
 

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Discussion Starter #18
Have you put 12V directly to the fuel pump to see if it runs? It is not unusual for new, out of the box electrical parts to fail. Very frustrating to your diagnostic efforts.
Not yet because I'm concern of flooding the engine and the effect of hydrolock mentioned by Fonzi in a previous thread.
Out of curiosity while waiting for the pump relay to arrive, I found 2 pump relays from the previous owner's "used part" and I bench tested them for functionality including the one that I removed from the car. They all function well and passed the circuit test. I re-install one of the used relay but still 0 voltage on the pump terminal.
Any suggestions as how to get power to the fuel pump?
 

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Not yet because I'm concern of flooding the engine and the effect of hydrolock mentioned by Fonzi in a previous thread.
Any suggestions as how to get power to the fuel pump?
Don't worry about hydolock, you are only going to run it for a brief moment to see if it works. Suggest a wire from the positive battery terminal or any other source of unswitched power. If you have a loose battery sitting around simply run wires from the battery terminals to the terminals on the pump.
 

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Discussion Starter #20
Not yet because I'm concern of flooding the engine and the effect of hydrolock mentioned by Fonzi in a previous thread.
Out of curiosity while waiting for the pump relay to arrive, I found 2 pump relays from the previous owner's "used part" and I bench tested them for functionality including the one that I removed from the car. They all function well and passed the circuit test. I re-install one of the used relay but still 0 voltage on the pump terminal.
Any suggestions as how to get power to the fuel pump?
I rigged out a test light connected to the terminals of the fuel pump so I don't have to disconnect them. No light when the key is ON but the light turns on when I tried to start the car. I also re-installed the pump relay prior to this test and the relay clicked when the key is on but the light is off.
 
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