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Discussion Starter #1 (Edited)
I picked up my 76 Shadow a few days ago after having the oil changed, new AC compressor installed, and a new lower column input steering shaft installed. After driving it for about 80 miles the car began stalling. The amber OIL warning light came on and fuel gauge stopped working. I can easily start the car after it stalls and it runs great for about 4 minutes; then it feels like the fuel is being cut off and it stalls. After getting the car home I tested it in the driveway letting it idle. It starts right up and then after four minutes the idle drops quickly and stalls. I checked the oil level and it’s fine. There is no overheating. There is no rough idle when it’s running.

I was told once that these later cars have a fuel pump cut-off safety mechanism connected to the oil pressure switch, so I disconnected the wire from the oil pressure sending unit (thinking I could bypass it) and it made no difference. The oil light is still on and the fuel gauge does not work. I checked the fuses and they are fine.

I suspect it has something to do with the fuel safety cut-off mechanism given the car's behavior, but I do not know enough about it to check other possible issues.

All guidance is appreciated.
 

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If your fuel gauge stops working you are not getting power to the ignition system. Check that the ignition fuse is clean and the terminals are tight. Also could be problem with the contacts in the ignition switch which is fairly common. Rig up a test light on your coil positive terminal, if it goes out when the engine dies that will point to the ignition fuse or switch. Do that test and report back.
 

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The later models with the oil pressure switch cutout appear to have two oil pressure switches. Are you sure you haven't just disconnected the wrong pressure switch.

I've no experience of these switches as my car is a 74 model. I was just curious as 4 minutes seems to be the time it would take to empty the float chambers, which is so consistent with the fuel pump stopping once the engine has started.

Geoff
 

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Discussion Starter #5
If your fuel gauge stops working you are not getting power to the ignition system. Check that the ignition fuse is clean and the terminals are tight. Also could be problem with the contacts in the ignition switch which is fairly common. Rig up a test light on your coil positive terminal, if it goes out when the engine dies that will point to the ignition fuse or switch. Do that test and report back.
Thanks. I did your test. I attached a test light to the positive terminal on my coil and it stayed on after the car stalled.
 

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Discussion Starter #6
The later models with the oil pressure switch cutout appear to have two oil pressure switches. Are you sure you haven't just disconnected the wrong pressure switch.

I've no experience of these switches as my car is a 74 model. I was just curious as 4 minutes seems to be the time it would take to empty the float chambers, which is so consistent with the fuel pump stopping once the engine has started.

Geoff
Thanks. Geoff. My car only has one switch.
 

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did you check the fuel filters? Mine will run well and then fail when fuel consumption is more than clogged filters will allow to pass - I have a rusty tank that I should replace. Maybe the oil warning is an unhappy coincidence?
 

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Discussion Starter #10
The next test should be to hook up your test light to the positive side of the fuel pump and see if it stays on after the car has started.
Interesting! The test light never came on. So I checked the fuel pump fuse and it was blown. I missed that when I was checking the fuses last night (embarrassing). This was an original fuse, almost 45 years old (see pic). So now the question is why did it pop while I was driving? Because it was an old weak fuse? Maybe I have a short? One thing is for sure, I'm going down the auto parts store and buy replacements for all my old fuses.

If anything comes to mind, please share your hypothesis of why this fuse popped.

Many thanks for getting me back on the road!
 

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Discussion Starter #11
did you check the fuel filters? Mine will run well and then fail when fuel consumption is more than clogged filters will allow to pass - I have a rusty tank that I should replace. Maybe the oil warning is an unhappy coincidence?
I have not checked the fuel filters in five years. It's something I need to do.
 

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Fuel gauge not reading was the relevant clue. Fuel pump fuse is also ignition fuse which powers the gauges. Fuses can look fine but the element can be making intermittent contact with the end caps. Clips can also be loose from overheating causing the same symptoms.
 

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Discussion Starter #13
Fuel gauge not reading was the relevant clue. Fuel pump fuse is also ignition fuse which powers the gauges. Fuses can look fine but the element can be making intermittent contact with the end caps. Clips can also be loose from overheating causing the same symptoms.
I just got back the store with new fuses and have replaced them all. Thanks Jim.
 

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I picked up my 76 Shadow a few days ago after having the oil changed, new AC compressor installed, and a new lower column input steering shaft installed. After driving it for about 80 miles the car began stalling. The amber OIL warning light came on and fuel gauge stopped working. I can easily start the car after it stalls and it runs great for about 4 minutes; then it feels like the fuel is being cut off and it stalls. After getting the car home I tested it in the driveway letting it idle. It starts right up and then after four minutes the idle drops quickly and stalls. I checked the oil level and it’s fine. There is no overheating. There is no rough idle when it’s running.

I was told once that these later cars have a fuel pump cut-off safety mechanism connected to the oil pressure switch, so I disconnected the wire from the oil pressure sending unit (thinking I could bypass it) and it made no difference. The oil light is still on and the fuel gauge does not work. I checked the fuses and they are fine.

I suspect it has something to do with the fuel safety cut-off mechanism given the car's behavior, but I do not know enough about it to check other possible issues.

All guidance is appreciated.
 

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I have a 1979 shadow oil light was not on but stalling like yours put a new fuel filter in and fixed my issue
 
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