1983 SC - Reviving after ~ 4 years dormant

[83_Silberpfeil]

Tony/PeteKz - continuing the thread from where I left off with LIRS6's thread that I hijacked....


I am trying to restart my 1983 SC, after letting it sit in the garage for past 3 years.

I've completed these items during past few weeks:
- oil change
- fuel filter change
- installed new H6 G48 AGM battery
- removed fuel tank bottom bolt, and drained old fuel
- installed new tank screen/bolt & gasket

Then I hit a wall. Tried run the FP to 1) make sure no fuel leaks; 2) build fuel pressure. But, the FP is not running. So, I've started asking for help in LIRS6's thread (http://forums.pelicanparts.com/porsche-911-technical-forum/978085-question-after-replacing-fuel-filter-accumulator-post11964774.html) , but got called out that I should have started my own new thread. So here I am, starting my own thread.

I'm going to repost my diagnosis, tests, and results here in the next few posts for continuity.

[83_Silberpfeil]

My latest test on the FP.

Using test leads that I put together, I connected FP directly to the car battery.

RESULT: As soon as the leads were connected to battery, I heard the buzzing from the CDI, the same buzzing you hear when the key is at "ON" position. But, the FP did not run. No sound, no vibration, nothing.

So, I do think that the FP is dead.

[83_Silberpfeil]

Other tests I've done, along w results, as guided by Tony and Pete Kz:

Tony & PeteKz --- Reporting back. I put together a proper jump wire w a 20 amp fuse and on/off toggle switch. See foto below.

The result : FP not running; I stuck my head under the car, and hand touching the belly pan where the FP would be just above. Did not hear anything; did not feel any vibration, or any signs of a moving mechanism down there.

Here's what I did, exactly:

FIRST TEST:
- removed red FP relay
- inserted one jump wire (JW) test lead (TL) into slot # 30 (6 o'clock)
- inserted the other JW TL into slot # 87a (11 o'clock)
- toggle switch in JW is "OFF"
-inserted car key, move to "ON" position
- flipped JW toggle switch to "ON
- CDI buzzing goes on
- I crawl under car to listen, put hand on belly pan near the FP position --- nothing moving, no sound down there. FP not turning on.

SECOND TEST:
- one jump wire (JW) test lead (TL) into slot # 30 (6 o'clock)
- other JW TL into slot # 87a (11 o'clock)
- toggle switch in JW is "ON"
-inserted car key, move to "ON" position
- CDI buzzing goes on
- I crawl under car to listen, put hand on belly pan near the FP position --- nothing moving, no sound down there. FP not turning on. Same result.

What's next? Connect battery power directly to FP? What is the procedure? What equipment do I need?

Thanks!

[83_Silberpfeil]

Additional tests/results, as prescribed by Tony/PeteKz

Tony & PeteKz --- Reporting back. I put together a proper jump wire w a 20 amp fuse and on/off toggle switch. See foto below.

The result : FP not running; I stuck my head under the car, and hand touching the belly pan where the FP would be just above. Did not hear anything; did not feel any vibration, or any signs of a moving mechanism down there.

Here's what I did, exactly:

FIRST TEST:
- removed red FP relay
- inserted one jump wire (JW) test lead (TL) into slot # 30 (6 o'clock)
- inserted the other JW TL into slot # 87a (11 o'clock)
- toggle switch in JW is "OFF"
-inserted car key, move to "ON" position
- flipped JW toggle switch to "ON
- CDI buzzing goes on
- I crawl under car to listen, put hand on belly pan near the FP position --- nothing moving, no sound down there. FP not turning on.

SECOND TEST:
- one jump wire (JW) test lead (TL) into slot # 30 (6 o'clock)
- other JW TL into slot # 87a (11 o'clock)
- toggle switch in JW is "ON"
-inserted car key, move to "ON" position
- CDI buzzing goes on
- I crawl under car to listen, put hand on belly pan near the FP position --- nothing moving, no sound down there. FP not turning on. Same result.

What's next? Connect battery power directly to FP? What is the procedure? What equipment do I need?

Thanks!

[83_Silberpfeil]

And more tests/results:

Pete/Tony: just go back from garage, after completing 12 V test at FP terminals. I didn't get 12 Volts, but not 0 Volts either. Two readings: 8.7 V and 9.5 V. And resistance across the FP terminals at 0 ~ 1.5 Ohms.

During testing, the pump did not turn on, did not run; no sound, no vibrations. After the test, the FP was warm to the touch; definitely a noticeable difference warmer than other parts down there.

- FP relay removed
- jumper wire w probes in pins #30 and # 87a
- jumper wire toggle switch "ON"
- key at "ON" position

First Test w Multimeter MM:
MM + probe to FP + terminal
MM - probe to FP - terminal
MM reading: 8.7 V

Second test w Multimeter MM:
MM + probe to FP + terminal
MM - probe to cross member bar as a grounding point
MM reading: 9.5 V

Third Test, Ohms w MM:
MM + / - probes to FP + /- terminals
MM reading: 0 ohms ; sometimes 1.5 ohms depending on where I contact the probes .

[boyt911sc]

Jonathan,

If I were in your shoes, I would perform these tests not necessarily in this order.

• Confirm that the FP relay is good and working.
• Test the 5 FP relay terminals are all functioning accordingly with the ignition switch at OFF/ON/START positions.
• Test the FP in situ and on the bench.

Since this motor has not run for many years, it would be prudent to test the FP either in situ or on the bench but requires some additional work like removing the heavy metal skid plate. This is a good time to look and inspect the condition of the fuel lines and wiring terminals.

Are you aware of the KISS method? The FP could be bad and we don’t know that as a fact. If you have a light bulb in your house that does work with the light switch ON, what would you do? I would remove the “non-functioning light bulb” and replace it with a known good light bulb. That’s how I would test it. Keep us posted.

Tony

[PeteKz]

As Tony said, keep it simple. If you have a spare relay, plug that in and see if it makes any difference. If you don't have a spare relay, I'll go counter to Tony here, because by jumping from the battery directly to pin 30, you have bypassed the relay, and a different relay "should" not work any better. The troubleshooting you have done so far strongly indicates that the problem is downstream of pin 30.

Did you whack the FP while you had the battery jumped to it? Try that too. It might start running. Could be that after that sitting, some crud has the FP jammed.

Looking at the results you have posted: something that jumps out at me is that you only measure 9.5 volts at the FP + terminal when you have 12 volts from the battery jumped directly to pin 30 in the relay socket (check your meter by measuring the battery voltage at the battery, should be 12.5 volts or slightly more). That pin goes directly to the + FP terminal, so it should read 12 volts. Sometimes the probes from the meter don't make good contact, so make sure you got good contact (also why you read between 1.5 and 0 ohms across the FP). If you still are not getting 12V, I am starting to suspect the wiring has a bad connection. However, it seems you have a good enough connection to pass enough current to heat up the FP. I would try loosening the + and - terminals on the FP, wiggling the wire "eyes" back and forth to scrape loose possible corrosion and retighten. Then test the connections again.

The ohms across the FP (from + to - terminals) should be zero, or just a couple tenths of an ohm. Recheck after you retighten the terminals. 1.5 ohms could be a poor contact to your probes, or corrosion on the terminal connections. If it stays at 1.5 ohms-ish, then my money is on a bad FP.

Question for Tony: In the later SCs, does the FP relay also power the CDI box? The printed out wiring diagram I have for a 1981 SC does not show a connection from pin 30 to the CDI. Remember, I have a 1973.5, which doesn't have this FP relay silliness.
I ask because he said that he heard the CDI box buzzing when he put power to pin 30.

[Cory M]

Are you putting your hand in the airbox and actuating the plate to turn the fuel pump on? On the SC the fuel pump doesn't turn on and start buzzing as soon as you turn the key like it does on a Carrera

[PeteKz]

Cory, he already did that. He is troubleshooting the FP because lifting the metering plate/arm did not make the fuel pump run, and even removing the relay and putting a jumper in the appropriate socket pins is not making it run.

[boyt911sc]

Originally Posted by PeteKz

Question for Tony: In the later SCs, does the FP relay also power the CDI box? The printed out wiring diagram I have for a 1981 SC does not show a connection from pin 30 to the CDI. Remember, I have a 1973.5, which doesn't have this FP relay silliness.
I ask because he said that he heard the CDI box buzzing when he put power to pin 30.

Pete,

Both the CDI and FP Relay will get power when you turn the ignition switch @ RUN. That’s normal. If you apply 12-volt to terminal #30, it could energize the CDI under these conditions:

• The ignition switch @ Off position.
• A good FP relay is installed.

Normally Closed (NO) 87a-30 is present for a good FP Relay. So if you apply 12-volt to terminal #30, power goes to the FP and 87A. Since the line to 87A is connected to S11 and S11 is connected to CDI @15, the CDI will be energized.

Not clear to me if Jonathan tested terminal #30 with the FP relay installed. If the FPR was removed, the CDI should NOT be effected.

Tony

[pampadori]

I feel like most of us are putting money on it being the fuel pump.

After meeting other g body owners and reading on these forums for 8 years, here are the super common failures I see mentioned most often:

• fuel pump no worky
• CDI no worky when hot
• turn signal/high beam stalk
• oil lines behind right rear wheel leaking at crimps
• crankcase vent tube hard and cracked/leaking
• rear sway bar mounts broken off chassis
• fresh air blower let the smoke out
• odometer gear broken inside speedo
• oil level sender
• oil pressure sensor

[83_Silberpfeil]

Tony - The two tests I conducted on Post #4 were done with FP relay removed. I can't visualize testing with FP inserted --- how?

Originally Posted by boyt911sc

Pete,


Not clear to me if Jonathan tested terminal #30 with the FP relay installed. If the FPR was removed, the CDI should NOT be effected.

Tony

[83_Silberpfeil]

Pete/Tony - thanks for further advice, and encouragement (on Post #7), and keep it simple. The next test I'm going to do tomorrow is:

- remove the wire/connectors from the FP
- FP relay removed
- Jumper wires into pins #30 and #87a
- Key @ "ON"
- apply MultiMeter probes to the two wires/connectors (for the FP)
- measure Voltage --- hopefully I will see 12. If I do, then I know FP is likely bad, then will remove and test on the bench. If I don't see 12 V, then there is problem w wiring, and I'll go up the path of the wire to the relay, to battery.

BTW, I took a few fotos of my FP. It doesn't look that bad at the terminal/connection.

[PeteKz]

Jonathan, don't forget to give it a friendly whack while you have power to the pump.

[boyt911sc]

Originally Posted by 83_Silberpfeil

Pete/Tony - thanks for further advice, and encouragement (on Post #7), and keep it simple. The next test I'm going to do tomorrow is:

- remove the wire/connectors from the FP
- FP relay removed
- Jumper wires into pins #30 and #87a
- Key @ "ON"
- apply MultiMeter probes to the two wires/connectors (for the FP)
- measure Voltage --- hopefully I will see 12. If I do, then I know FP is likely bad, then will remove and test on the bench. If I don't see 12 V, then there is problem w wiring, and I'll go up the path of the wire to the relay, to battery.

BTW, I took a few fotos of my FP. It doesn't look that bad at the terminal/connection.

Jonathan,

Put away the VoM and use a test light. I use the TL for checking voltage and continuity for this kind of investigation. This is how I set up the TL:

• Connect one end of the TL to a power source (12-V) to look for ground.
• Connect one end of the TL to a ground source to look for power.

You want to verify and confirm if the TEST LIGHT will lit or not. This is my version of a continuity test and very effective to identify your problem/s. You are on the right track.

Tony

[83_Silberpfeil]

Originally Posted by PeteKz

Jonathan, don't forget to give it a friendly whack while you have power to the pump.

Thanks for the reminder PeteKz --- will be sure to do that!

[83_Silberpfeil]

Great suggestion Tony --- but I don't have a test light. Will either order one from Amazon, or pick up one on next trip to Harbor Freight.

I like the idea of using a Multimeter because in addition to checking for power, I can read the voltage --- looking for 12 V. From what I've seen, the basic automotive TL pen doesn't read/display voltage, only confirms there's some power. Correct me if I'm wrong.

Recall in one of my previous posts, I got reading of 8.7 V using the MM with probes on the +/- posts on the FP.

For my next test, instead of reading at the +/- posts of FP, I will read at the +/- wires and connectors from the car. Hopefully it will read 12 V.

Originally Posted by boyt911sc

Jonathan,

Put away the VoM and use a test light. I use the TL for checking voltage and continuity for this kind of investigation. This is how I set up the TL:

• Connect one end of the TL to a power source (12-V) to look for ground.
• Connect one end of the TL to a ground source to look for power.

You want to verify and confirm if the TEST LIGHT will lit or not. This is my version of a continuity test and very effective to identify your problem/s. You are on the right track.

Tony

[boyt911sc]

Originally Posted by 83_Silberpfeil

Great suggestion Tony --- but I don't have a test light. Will either order one from Amazon, or pick up one on next trip to Harbor Freight.

I like the idea of using a Multimeter because in addition to checking for power, I can read the voltage --- looking for 12 V. From what I've seen, the basic automotive TL pen doesn't read/display voltage, only confirms there's some power. Correct me if I'm wrong.

Recall in one of my previous posts, I got reading of 8.7 V using the MM with probes on the +/- posts on the FP.

For my next test, instead of reading at the +/- posts of FP, I will read at the +/- wires and connectors from the car. Hopefully it will read 12 V.

Jonathan,

You are making the troubleshooting more difficult than it should be. You could be trying to resuscitate a dead body. You had used a lot of your time. This simple diagnostic test should take only a few mins. to determine the condition of a suspect FP.

You don’t need to know at this point the voltage or resistance, what you need to know is the continuity between two (2) points or terminals. Look for the culprit causing the problem. Just test the FP by applying 12-volt to the positive (+) terminal of the FP with or without a test light hooked up. The FP will not run without a good ground.

Tony

[83_Silberpfeil]

I got back under the car. I conducted three tests (one of them was a re-test). I can confirm the FP is dead.

Test 1 (I tested this a few nights ago, re-testing to be absolutely sure):
- FP in place, with car wiring connected to terminals of FP
- using test lead, connected FP directly to battery
RESULT: FP does not run ; CDI buzzing comes on

Test 2:
- remove/disconnect car wiring connectors from the FP terminals
- connect car wiring connectors to Multimeter +/-
- remove FP relay
- jump relay socket pins 30 & 87a
- turn key to "ON"
RESULT: MM reads 12 V --- I have power all the way to the wiring connectors

Test 3:
- remove/disconnect car wiring connectors from the FP terminals (still removed)
- using test lead, connected FP directly to battery
RESULT: nothing also; FP does not run ---

@PeteKz --- I did give the FP a few polite whacks before the tests.
@Tony --- totally get it that this should be simple, easy, taking only a few min. I'm very new at this type of wrenching, and don't have a TL pen. So did what I could, w a MM. I may have made it more difficult that it had to be, but this is a learning process that I needed to go through.

TEST 1


TEST 2 and 3

[boyt911sc]

Jonathan,

Your next test is to connect the (+) and (-) wires of the FP to a test light to mimic a load (FP). If you could not make the light bulb to lit by bridging terminals 87A & 30 with ignition switch @ RUN, there is something preventing to complete the circuit.

But if you could get the TL to lit doing the above test, you are good and will only need a replacement FP. Good luck.

Tony