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Discussion Starter · #1 ·
Hello everyone, been a while. Lucille has had no issues for several years since I worked the bugs out, but I suppose we're due for some trouble.

I had her running in the driveway for several minutes, just about to charge the A/C, went to connect the hose and she sputtered and died. I restarted, immediately started up and immediately died. Okay, check fuses, check spark, check fuel -- add fuel. Nothing. Starts and dies.

Pierburg pump. I hear it, good power. It pressurizes and stops. Turn the key and it starts immediately, then dies immediately.
Wouldn't think a fuse if it starts at all, and I can hear the pump running in any case. I pulled all the ones used for ignition and they look fine.

Once again, it was running when this happened. Backed it out of the garage, opened the bonnet, connected the A/C hose. That's it.

What are we thinking next, fuel pressure sensor maybe? I've replaced it once with a GM one of the same thread, but I suppose anything is possible at this point.
 

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Check for spark. Most likely Opus ignition module withinthe distributor. Checking for spark when turning the key will confirm. Pull the coil lead out of the distributor cap and hold approx 1/4" away from a metal item that is chassis ground.
 

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Pierburg should keep running as it is a circulatory system. Pull off float vent hoses on fuel receiver to eliminate a fault with the anti run on or weakener solenoids. Maybe you dislodged a connection on one of those when connecting to the low pressure AC port. No power to a particular one will put full engine vacuum on floats and the engine will stall out. Will start for a second then stall out quickly again when vacuum builds.
Or is this a late California spec car with FI?
 

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California cars with fuel injection were 1980 only and available from March 1980 thru December on Shadows and Wraith II's. SY cars.
 

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Discussion Starter · #6 ·
Thanks Jim. I never did get around to replacing the anti run-on solenoid, but I'm not sure it's even getting power to the wires. Nothing's changed though. I do have an extra solenoid somewhere if I have to wire it in.

This car has always had a double-start issue, that I've isolated to something with the smaller oil pressure switch (part of why I replaced it with the GM one). It always dies on first start, after 60-90 seconds of running, and I have to "catch" it and restart quickly before the oil pressure goes down all the way. I've never been able to find the relay. I've replaced several, but the wiring diagrams are... well, you know. I'm hoping the relay finally didn't die, because I'm all out of ideas on where to look. Yes, I tried under the dash.

But this was after the car was running just fine for several minutes. It just suddenly shut down, and will not proceed.
 

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Discussion Starter · #7 ·
Swapping out the anti-run-on solenoid with a working one did nothing. I'll have to see if I can post a video. It doesn't strike me as the same type of dying -- it's not dieseling and then dying, it just cuts off. Like if you sprayed starter fluid into an engine that wasn't getting fuel. Just up and right back down. One 'vroom' and it quits.

Is it possible the relay that drives the oil pressure sensor is stuck? That's been a theory I've had for a while with the double-start issue, but the more I think about it, that relay drives the fuel pump, doesn't it? I wouldn't hear the Pierburg at all if that was the case, right?

The other thing, Jim, is that yes everyone says it's a continuous flow system, and in fact I had to rebuild part of the return line once, but it's always pressurized and stopped on this car. It's weird.

I'm stuck, guys. I don't know what else to look for. All these are the usual culprits, and I checked them before posting. I did remove the carb vent hoses. Might be time to replace those little bits of hose -- they're crispy and loose. Maybe that's why the solenoid has never been an issue, I don't know.

I'm stuck. And I was going to do a wedding tonight, too. Might have to ruin someone's wedding. =\
 

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Jump the oil pressure switch to ground and see what happens. If I remember, it's a white wire with brown stripe.
 

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Explain what you mean. The pressure switch actually continues to ground when oil pressure is reached allowing the car to start .It needs approx 15lbs of pressure to close the switch. It's a safety feature that does not allow the car to start unless pressure is proven.
 

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Discussion Starter · #11 ·
Well I unplugged the wire, jammed my test light in it, and clipped it to the frame. Never came on.

I thought the way it worked was that a relay ran the fuel pump until oil could get to pressure, then it clicked over. Maybe I had it wrong.
 

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There is no voltage at the sensor. It simply grounds out when pressure is reached. Voltage is at the relay. Take a test lead with alligator clips on both ends and put one on the lead and another to the chassis and see what develops.
 

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JA, I meant to just pull the vent hoses off wherever is easiest to open the carb float bowl vents to atmosphere, removing any possible fault in a solenoid from the equation. I was thinking you may have dislodged a wire around those solenoids when you were attaching the AC connections near them which is now affecting the carb float bowl venting. Try pulling the wires off both small oil pressure switches and leave them off to see if pump then works and engine starts. Next would be to find the relay up under the dash above steering column that the no oil pressure switch controls and jumper terminals on it to make pump always run with ignition switched on. Perhaps before doing that though run a 12 volt source directly under car to fuel pump and see if it will start up then. Odd that the pump stops when pressurized, maybe faulty and it's stalling out when pressure on it but I wouldn't think it would last very long doing that.
 

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First you have to prove if the problem is the ignition or the petrol. You can test the ignition with a direct wire from the battery to the coil. When starting the central lead has to spark and keep the motor running.
For the petrol you can prove if there is petrol in the floatchambers of the carbs when the motor stalls. With this knowledge the search is much easyer.
 

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Discussion Starter · #16 ·
Yeah I can test at plugs but it does turn over, good strong start. Just dies immediately. I tried starting without the oil pressure connected. No dice.

Today I removed and checked fuel filter, looked great. Then connected fuel pressure gauge at engine, 7psi. Interestingly, return fuel line was dry.

I’ve looked for the relay you’re describing and simply can’t find it. I’ve been over every one under the drivers dash and replaced a lot of them with modern relays. Guess I’ll take another stab at it.

I like the idea of direct powering components though. I’ll see what that reveals.
 

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Discussion Starter · #18 ·
Did you ground the wire when pulled off the oil pressure switch? It has to be grounded.
With my test light, yeah. Clipped it to a bolt. But it sounds like that was the wrong order. I need to do as suggested, which is what I did the last time I messed with this. Alligator clip oil switch to test light, test light to wire. Set phone, start video, run around and start car. Around we go again.

If I do the same thing with the fuel pump wire and a second test light, I can see exactly what’s going on.

I’m betting it’s the relay. It acts like it. I just need to find it. OR - it’s the wire from the oil switch to the relay. Since I can’t find a bad one. I need to run a wire out from under the car, I just need to definitively find that relay.

For now, a question: Back to the solenoid, where do the wires on the anti run on solenoid terminate? I want to check the other end and try bypassing those too. I suspect they may be toast as well.
 

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John, get rid of the damn test light. It will prove nothing. For the last time simply ground the wire that was attached to the sensor.
 

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Discussion Starter · #20 ·
John, get rid of the damn test light. It will prove nothing. For the last time simply ground the wire that was attached to the sensor.
I did, both yesterday and this morning. I can try again with alligator clips instead of test light but I’m not sure of the integrity of the wire at this point since the light never came on. Then again, if the wire was crispy in there somewhere that might effectively ground it anyway.

The point of the test lights is to figure out if the oil switch is cutting off the pump. One comes on, one goes off, etc. I don’t know how else to see what’s going on.

Walk me down the wire here…
This is what I have for how it’s supposed to work:
  • Ignition turns to run
  • relay delivers power to fuel pump
  • car starts, oil comes to pressure
  • oil switch goes to ground, relay clicks over
  • fuel pump is now dependent on oil switch

Do I have that right, or am I missing something?
 
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