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Discussion Starter #1
Greetings,
Does anyone know where the two wires that come out from the bottom of the pump goes?? I have converted from carbs back to Spica and I don't have a clue on where these wires plugs into. Any help would great appreciate it. Also, I am new in the Alfa world, so please be gentle.

Thank you in advance.

Q-man
78' Alfa Romeo Spider
 

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One wire goes to the top of the fuel cutoff solenoid and the other to a wire that comes from the right front of the engine compartment.
 

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It really doesn't matter. I'm out-of-town right now so I don't know exactly, but the wire that goes to the car's electrical system has a straight spade connector, while the fuel cutoff solenoid spade connector has the wire attached to the side of it.
 

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Discussion Starter #5
John, I bought this car a year ago, the previous owner had converted over to carbs, which he had cut all the wires and the ends. Now, when I gone back and converted it back to the Spica fuel injection pump, I have nothing to go by. I have looked at a lot of manuals and nothing cover a picture of a wiring. I can follow instructions really good, if I have something to go by.

Thanks for your help.
 

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If you can't find the original wire what you want is a 12 volt feed to the microswitch on the bottom of the pump. The microswitch will close when the throttle is closed and the engine rpms are over 1200 (or thereabouts) This actuates the fuel cutoff during deceleration. It's more an emissions device than anything else but you will get some backfiring during decel if it's not hooked up.
 

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Actually the fuel cutoff solenoid and microswitch is redundant to the mechanical shutoff system internal to the pump. It's not absolutely necessary to the system. My microswitch broke (shorted) about a year ago and I'm still waiting for time to R & R the FI pump. Runs fine with no backfiring without it.
 

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Roadtrip

Don't know of any mechanical shutoff in the pump other than the mechanism that actuates the microswitch. The cutoff solenoid plunger is operated electrically. The fact that you have no backfiring with it disconnected is not uncommon. You're probably running rich. How old is your T/A?
 

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Discussion Starter #11
Spica pump wiring

Roadtrip - So, what you're saying that the white wire from the micro switch should be connected to the solenoid that faces the radiator, correct? What do I do with the black wire that also come out from the bottom of the switch?

Please let me know.

Thanks, guys!!


Roadtrip said:
Actually the fuel cutoff solenoid and microswitch is redundant to the mechanical shutoff system internal to the pump. It's not absolutely necessary to the system. My microswitch broke (shorted) about a year ago and I'm still waiting for time to R & R the FI pump. Runs fine with no backfiring without it.
 

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The internal fuel cutoff, I believe, is a specific postion on the 3D cam. As the throttle is returned to idle, fuel is cutoff until the engine speed drops below approx 1300 rpm, where the inertia balls allow the spring to push the 3D cam back, thus restoring fuel flow. My system is running with correct mixture as evidenced by the color of the plugs and general running. The FCS provides a more positive fuel cutoff, but the internal one works fine as well. The early pumps ('69) did not have a FCS and only had the internal one (which was adjustable).

Assuming the mixture is in-tune, the usual cause of backfiring is throttle butterflies that aren't closing completely at idle.
 

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I'm sorry to interrupt. John, could you tell me what this part is called? I know where it goes but dont' know it's name. Thank you.
 

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That's the "Preliminary Idle Adjustment".
 

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Re: Spica pump wiring

Q-man said:
...What do I do with the black wire that also come out from the bottom of the switch?
Either wire from the microswitch can go to the cutoff solenoid; doesn't matter which. The other wire from the switch needs to be hooked up to the white wire that's in the engine wiring harness. If the white wire isn't in the harness, cut by the PO perhaps, then any switched power source will do; the + side of the ignition coil as an example. I would recommend an 8 amp inline fuse and 16 ga wire minimum if any wire other than the original white wire is used.
 

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Discussion Starter #16
Re: Re: Spica pump wiring

Got it!!

Thanks, Jim

Q-man
78' Spider

papajam said:
Either wire from the microswitch can go to the cutoff solenoid; doesn't matter which. The other wire from the switch needs to be hooked up to the white wire that's in the engine wiring harness. If the white wire isn't in the harness, cut by the PO perhaps, then any switched power source will do; the + side of the ignition coil as an example. I would recommend an 8 amp inline fuse and 16 ga wire minimum if any wire other than the original white wire is used.
 

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Like Papajam says it really doesn't matter. The microswitch is just like a light switch and interrupts the current through the wire. It should be obvious which female spade terminal goes to the Fuel Cutoff Solenoid. In my car the female space terminal that goes to the FCS has the wire connected to the side of the spade terminal.

67 GTV - Since I'm in a hotel in Chicago right now and don't have access to my manuals, I'm not sure what the exact nomenclature of that part is. But, I think it's something like "Idle Air Distributor." It is (or should be) the only source of idle air for the engine. Air flows into the large hole, flows through a rubber O-ring then into the block where it is distributed to each intake manifold. The throttle butterflies should be "just" closed (so they don't dig into the aluminum barrels) at idle. The amount of air into the distribution block is varied by compressing the special rubber O-ring with the screw-in adjuster (large pipe).

Many times when backfiring is present at decel, you'll find that the throttle butterflies are slightly open, with the long rod holding the throttle open slightly also. This is usually done in an attempt to adjust the idle in the incorrect manner. If you haven't replaced the O-ring recently, you many find the idle difficult to adjust because the O-ring has lost it elasticity.
 

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Thanks guys! I'm getting ready to sell this part and calling it a "Spica Thingie" just wouldn't do. :D
 

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I doubt if anyone will be interested in buying it. About the only thing that can break on it is the pinch bolt flange for the barrel adjustment. In any case, it probably isn't worth the trouble of putting it on ebay.
 
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