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You can determine if the problem is fuel or ignition by having someone spray starter fluid into the air cleaner and then dis-engaging the starter. If the engine keeps running it is a fuel problem. If it quits, it is an ignition problem.

You could also disconnect the cold start solenoid from the starter and power the solenoid with a jumper from the battery while starting it. Same results as above.

Thanks for the suggestion Alfa69GTV1750 but all rods are attached. I was really hoping that was it!

So far I've confirmed that fuel pump has power both at the run position and start.

The car will die with both the green/black wire and jumper attached to the coil as well.

The car starts fine with the cold start hot wire detached but dies like usual when the starter is disengaged.


One thing I did see is that per Wes Ingram the fuel cut off solenoid can cause the symptoms I discribed if the micro switch is shorted. Unfortunately the FCC was unplugged but I'm wondering if it's jammed up or something. I'm going to apply a 12v source to it and see if I can hear it click.


Thanks for the help!
 

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One thing I did see is that per Wes Ingram the fuel cut off solenoid can cause the symptoms I discribed if the micro switch is shorted. Unfortunately the FCC was unplugged but I'm wondering if it's jammed up or something. I'm going to apply a 12v source to it and see if I can hear it click.
If the car is getting fuel when the starter is running, then I don't see how the FCC would shut the fuel off when you go back to "run". Since the FCC is unplugged, it wouldn't know whether the starter was running or not, even if there's some weird electrical connection. Still, it'll be interesting to see if it clicks when power is applied; there must be some fault that caused the PO to disconnect it.

Alfa69GTV1750 said:
You can determine if the problem is fuel or ignition by having someone spray starter fluid into the air cleaner and then dis-engaging the starter. If the engine keeps running it is a fuel problem. If it quits, it is an ignition problem.
I like that idea.
 

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Discussion Starter #23
Update

Alfa69GTV1750, that was a good suggestion! The does continue to run when I spray start fluid. So fuel is being cut but not ignition.

Alfajay, I'm not sure either but I pulled this from the Wes's roadside manual.


"IV. SYMPTOM:
Engine stops suddenly or exhibits random "cutting-out." Restart attempts fail, although the engine
may initially fire, but then die as the key switch is released from the start to the run position.
1. POSSIBLE CAUSE: Shorted Fuel Cutoff Solenoid (FCS) microswitch on bottom of pump causing
steady current to be delivered to the FCS, thus cutting off all fuel delivery. Restart attempts may result in
initial firing until the key switch is released because with the key switch in the "START" position, current is
cutoff from the FCS microswitch. Thus, there is no power to the shorted microswitch. When the key switch
is released to “RUN,” power is restored to the shorted microswitch and the FCS again cuts off the fuel"

Also the FCS has a solid click when 12v is applied and I can hear it click again when removed so it's probably not stuck.
 

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I'm not a SPICA expert, but that means with the starter engaged, the SPICA system is delivering enough fuel to the engine to start. I can't think of anything that would give these symptoms other than a problem with the throttle rods to the SPICA pump. Are you sure the long rod is connected at the pump?

What happens if you give the engine full throttle when running with the starter engaged? If you try that and the engine dies, it may be that while cranking, the engine is running on the cold start solenoid only which is powered from the starter.

Inversely, what happens if you disconnect the cold start solenoid? Does the engine still start?

Alfa69GTV1750, that was a good suggestion! The does continue to run when I spray start fluid. So fuel is being cut but not ignition.

Alfajay, I'm not sure either but I pulled this from the Wes's roadside manual.


"IV. SYMPTOM:
Engine stops suddenly or exhibits random "cutting-out." Restart attempts fail, although the engine
may initially fire, but then die as the key switch is released from the start to the run position.
1. POSSIBLE CAUSE: Shorted Fuel Cutoff Solenoid (FCS) microswitch on bottom of pump causing
steady current to be delivered to the FCS, thus cutting off all fuel delivery. Restart attempts may result in
initial firing until the key switch is released because with the key switch in the "START" position, current is
cutoff from the FCS microswitch. Thus, there is no power to the shorted microswitch. When the key switch
is released to “RUN,” power is restored to the shorted microswitch and the FCS again cuts off the fuel"

Also the FCS has a solid click when 12v is applied and I can hear it click again when removed so it's probably not stuck.
 

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Discussion Starter #25
Yeah, this has got me stumped as well.

I've been doing these tests, since your either spray idea, with a remote starter switch. The engine responds really well to throttle response when I turn the bellcrank with all arms moving as they should.

My next move I guess will be hooking up a pressure gauge and seeing what I'm getting at rest then seeing if I get a spike or something during cranking.
 

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Disconnect the cold start solenoid and see what happens. Even if you are using a remote starter switch, the cold start solenoid is engaged when the starter is powered.

Yeah, this has got me stumped as well.

I've been doing these tests, since your either spray idea, with a remote starter switch. The engine responds really well to throttle response when I turn the bellcrank with all arms moving as they should.

My next move I guess will be hooking up a pressure gauge and seeing what I'm getting at rest then seeing if I get a spike or something during cranking.
 

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with the key switch in the "START" position, current is cutoff from the FCS microswitch. Thus, there is no power to the shorted microswitch. When the key switch is released to “RUN,” power is restored to the shorted microswitch and the FCS again cuts off the fuel"

Also the FCS has a solid click when 12v is applied and I can hear it click again when removed so it's probably not stuck.
OK, we're making progress. Alfa69GTV1750's suggestion to spray starting fluid was the breakthrough - now we know it's fuel related and not ignition. And we know it's the Spica pump, not the fuel pump.

That quote from Wes Ingram comes close to explaining the situation. And the fact that your fuel cut-off switch was disconnected suggests that a PO encountered this problem and dealt with it by disabling the FCS feature (which results in backfires on deceleration).

Like Alfa69GTV1750, I'm not a SPICA expert either. For example, I didn't know that the ignition switch sends current to the fuel pump and coil in the "start" position, but not to the FCS - I wouldn't have thought it was that complex.

Motoital2.0 said:
the FCC was unplugged but I'm wondering if it's jammed up or something.
But something still has me puzzled: If the FCS microswitch was disconnected, how did the Spica pump know when the ignition key was turned from "start" back to "run"?

Motoital2.0 said:
It starts up fine with the css disconnected. Not much difference.
Unlike a disconnected FCS, a connected CSS would know when the starter was on. I can imagine a situation where the Spica pump is set so lean that the engine can't run unless the CSS is enabled. But you reported that it behaves the same way whether the CSS is connected or not, so I'm still baffled.
 

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Maybe the FCS is wired incorrectly? Could it be frozen in the wrong position and the click is the solenoid, but not the valve? Maybe take it out and see if there is external movement when energized and de-energized?

OK, we're making progress. Alfa69GTV1750 suggestion to spray starting fluid was the breakthrough - now we know it's fuel related, and not ignition. And we know it's the Spica pump, not the fuel pump.

I think that quote from Wes Ingram explains the situation. And the fact that your fuel cut-off switch was disconnected suggests that a PO encountered this same problem and dealt with it by disabling the FCS feature (which results in backfires on deceleration).

Like Alfa69GTV1750 said, "I'm not a SPICA expert". I'm sort of surprised that the ignition switch will send current to the fuel pump and coil in the "start" position, but not to the FCS - didn't know it was that complex.

But something still has me puzzled: If the FCS microswitch was disconnected, how did the Spica pump know when the ignition key was turned from "start" back to "run"?
 

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Discussion Starter #31
But something still has me puzzled: If the FCS microswitch was disconnected, how did the Spica pump know when the ignition key was turned from "start" back to "run"?
I'm a bit baffled as well. It's not like I'm new to spica either. My 74 still has it. I'm going to read through the FI manual from Wes and see if it elaborates anymore on the starting circuit.

Alfa69GTV1750, I'm probably going to have to pull the FCS to verify that everything is as it should be. Just waiting on the tool.

I'm waiting on a few parts to arrive so I've been cleaning electrical connections here and there. Haven't seen a clean connection yet. Part of the fun of a new to you car. I came across this loose braided wire. Does anyone know what this connects to? IMG_20190404_102545.jpg
 

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Don't remember about the braided wire (maybe a temperature probe wire from the cat? Our 78 GT had one), but bypass that inertia cutoff switch. Just hook the two wires together. That thing was a pain in the neck on our cars which had it. Every time we hit a bump... the engine shut off.
 

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What does the inertia switch turn off?

Might the starter bypass it and it is causing the problems? If it turns off the fuel pump, which I assume it does, that might be the problem.


Don't remember about the braided wire (maybe a temperature probe wire from the cat? Our 78 GT had one), but bypass that inertia cutoff switch. Just hook the two wires together. That thing was a pain in the neck on our cars which had it. Every time we hit a bump... the engine shut off.
 

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Didn't look into it, just bypassed it after several occurrences of the engines quitting in the middle of intersections, etc. I think it is suppose to shut off the fuel pump. Engine does quit almost at once though, so it also might be the ignition. Others will know better. I do not remember any longer. Been a long time since our Alfettas.

Just bypass that sucker is my advice, regardless.
 

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Discussion Starter #35
Thanks Del, that might be it as it snakes down under the car. The cat is long gone now though. That might be why it's disconnected.


Might the starter bypass it and it is causing the problems? If it turns off the fuel pump, which I assume it does, that might be the problem.
That was the first thing I checked. I wish it was that simple. There's some questionable wiring from the po that I discovered so I'm dealing with that until my parts arrive. Unfortunately the manual I have is for non US Alfas. If anyone has a color wiring diagram I'd greatly appreciate it. I was super bummed to find out about Papajam.
 

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A diagram and some thoughts.
The car should start but not accelerate without the fuel pump on. Mine does.
The braided cable is the "RUN YOUR CATALYTIC CONVERTER IS ABOUT TO MELT" system. Appropriate in the 1970s. Probably not connected to anything now.
The thing with the plunger on the passenger side firewall is the "darn my Alfetta has rolled over and please turn off the fuel pump" thing. It fails in the no power to the fuel pump. Mine has failed and I jumped the wired together. Gotta get a new one from Summit Racing.

Trivia: The CAT melting cable leads to a weird electronic board tucked up in the passenger side above the glovebox. Looks like a Radio Shack science project. It then leads to the "SLOW DOWN" dash light. Alfa trainers called it the "popsicle" back in the day.
AlfaJay and I and about 15 others are loading up our Alfas and heading up to Central Calif for our AROSC Wine Tour. If you get any posts from either of us later tonight just ignore them as they may be "wine influenced". Or maybe our thoughts could be more clear as they would be unencumbered with reason.

RIP PapaJam. Thanks for the help.
 

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Wasn't implying that the inertia cutoff switch was the cause of your problem, was just suggesting that you bypass it, just because it can bite you at inopportune times, as we found out. It's not worth having it if you get stuck in the middle of traffic with the fuel pump shut off as happened to us a few times.

Good luck with your problem. You will get it solved. My mechanic had a Marelli(?) tester, which might find such a problem as yours. Pretty sure he used it on our 78 Alfetta sedan when we had some sort of similar problem. Don't remember what it was though. I remember his showing us the tester, saying that it did come in handy now and then. Don't know if anyone in your area has one. Evidently quite rare.
 

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Discussion Starter #38
Trivia: The CAT melting cable leads to a weird electronic board tucked up in the passenger side above the glovebox. Looks like a Radio Shack science project. It then leads to the "SLOW DOWN" dash light. Alfa trainers called it the "popsicle" back in the day.
I was wondering what that board with the single fuse was for. Thank you for the diagram! So much easier to read. And the Alfa wine tour sounds like a blast


Del, yeah I probably will just bypass the switch. Seems like a lot of people have had problems with it.
 

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Discussion Starter #39
Update

I got her running! It ended up being the thermostatic actuator. It was stuck in an extended position. The set screw was out of wack as well. I need to go over system as the lower rod is keeping the throttle from completely closing. Along with a few other things.

I want to say thanks to all of the people who helped out. I learned a lot.
 
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