[Dickson]

I degreased my engine compartment yesterday. Oh the gunk that came off!

While it looks great, the car did not start afterwards. I used the leaf blower to "blow dry" the engine and compartment pretty well, but no joy.

Help! Wiring questions:

1. The spark plugs / pistons are 1/2/3/4 going front to rear from Olio, correct?
2. Starting at the top left of the four plug inputs on the distributor cap and going clockwise, what is the firing order?
3. I found one loose wire from the coil. See blue tape in pic:

4. I suspect that the orange wire might have been crimped together with this one. See other blue taped wire with crimp end:

I currently have no spark, so it's an electrical issue. If I can confirm that the plug wires did not get crossed, and perhaps run a replacement wire off that coil (no splice) I think this will get solved.

Thanks for any help! Dickson

 

[Tifosi]

1. The spark plugs / pistons are 1/2/3/4 going front to rear from Olio, correct?

Correct

2. Starting at the top left of the four plug inputs on the distributor cap and going clockwise, what is the firing order?

Firing order is 1-3-4-2, but there's no gaurentee that #1 is at the top left.
(most of the time its more between 1 and 5 o'clock with 3 being the most desireable according to the standard assembly practices)
Roll the engine up to TDC on #1 compression stroke and pop the dizzy cap to see where the rotor is pointed to find #1 terminal.

3. I found one loose wire from the coil

I've no clue on that

 

[Dickson]

Thanks Darren. The firing order will be relatively easy to correct if needed.

However, I suspect it's that single wire off the coil that is the reason for no spark.

 

[ghnl]

Do you have a copy of PapaJam's color-coded wire diagrams for your model Alfa? You should. It will make chasing Alfa electrons much easier.

If you do not, send him a request via PM, include your email address and prepare to be wowed. (unless you have a GTV6 - then all I ever hear is, "I'm working on it...")

 

[Dickson]

Sounds like a "must have"....

 

[144]

There should be a black wire going from the neg (-) side of the coil to the connection on the underside of the distributor. This spade terminal loosens up over time and can get loose resulting in intermittent ignition missing. It looks like a PO did some "custom" wiring there and left a hot "wire to no where looking for a short" coming off the coil. Plug wires tied to the upper radiator hose is a nice custom feature as well. Here's a swatch of the wiring diagram, although I don't think is shows a wire from the neg term to the ballast resistor. It think my 74 has that, but I'm not at home to check it for you until next weekend.

 

[Dickson]

Thanks. I hope that's it.

Methinks the "custom" wiring was free with the purchase of the car....As was the extensive rust....ala "rust free"

 

[poods2]

Wiring diagram

I don't know how much Papjams schematic will help due to the custom wiring on your car but here is was he gave me. That heavy gauge red wire is usually for the inertia switch. Thank him if your contact with him.



v View attachment 6812d1083088326-10562-1750-spider-veloce-1971-electrical-diagram-10562-1750-spider-veloce-1971.pdf

 

[poods2]

wiring

Oh ya, as Roadtrip mentioned it's more than a good idea to move the ignition wires from the radiator line. The hotter they get the less resistance they offer never mind melting the cases. Probably not the problem right now but will be eventually. Was there any condensation in the distributor or points and is there a capacitor on coil? I don't recall seeing one, also check fuse #11, and I believe on 1974 there is an inline fuse on the right fender that powers the fuel pump.
Best of luck,
Kevin

 

[Alfastruns]

That heavy gauge red wire is usually for the inertia switch. Thank him if your contact with him.

v View attachment 204200

There is no inertia switch on a '74 !

 

[144]

Green/black from ignition switch to one side of ballast resistor
Any color wire from + terminal of coil to other side of ballast resistor
Green to + terminal of coil
Black (from distributor) to - terminal of coil

If you have a Petroinix installed:
Black wire from Petronix to - terminal of coil (Stock black wire to distributor is removed)
Red wire from Petronix to + terminal of coil
All else remains the same.