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Discussion Starter #1
The car is a 77 Alfetta GTV with single point distrbutor. It has a new Bosch coil with internal resitor. Power off the wires at the coil is 11.9 Volts. Power with wires connected to coil with switch on is 10.9 Volts. Power during cranking is 8.5 Volts. The coil - side has two wires, condenser and ground. The + side has a green wire and a black wire (I am unsure of this one). The distrbutor has a new condenser, points and cap. Plug wires are Taylor brand and in good condition. This is my third Alfetta (two GTV's and one sedan). I have never seen this kind of melt down before. Guys, I am in a bad spot. I wanted to take her to the French Italian show at Woodley Park (Van Nuys Ca) today, but she has turned into a bad date. I just need to get some spark out of the coil H/T wire. :confused::mad:
Thanks jetsetrj
 

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The battery voltage sounds way too low. Have you tried a different battery or booster cables?
 

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Discussion Starter #4
No Spark at coil?

Yes I have tried booster cables. Crank was at 12.2 volts. With out boost crank was at 10.9 volts. Still no spark from coil. I am missing something in my trouble shooting. Is there a relay in the start cycle or a ground wire issue? I am stumped ! :mad::mad::confused:

jetsetrj
 

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I posted a response in this thread but this electrical forum may be the better place for this question. My post from the other thread posted below;
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Your Alfetta was originally fitted with a ballast resistor so I need to ask exactly how is the new coil hooked up? There should be a single green/black stripe wire to the coil positive terminal. The green wire on coil positive, used with the old coil, will not be used and should be taped up and secured out of the way.

If you take a voltage reading from the coil negative terminal while cranking, is the voltage steady? Or does the voltage vary between zero and coil input voltage?
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For testing purposes, the coil condensor can be disconnected (and to eliminate it as a suspect). The wire on coil negative goes to the points, not directly to ground. Can you post a pic of the coil & wiring?
 

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Discussion Starter #6
No Spark at coil?

Since last thread I have cleaned key switch, pulled all fuses/ relays and cleaned contacts of fuses (you never know with electrical). The schem showed wire back to the fuse box (VN-1 S), thought it would help, still no spark. Yes Jim (if your out there) I have some shots of the coil with different wire configurations and readings.

jetsetrj
 

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Trained (ex)Professional, , 1953-2018 RIP,
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Does your car have the original dual point distributor as well as the ignition advance relay and wiring? If so, having the correct wiring diagram will help with the next couple of tests. If you send me your email address, I'll send you the diagram. Does your Alfetta have A/C?
 

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Discussion Starter #8
No Spark at coil?

I have two spare engines I use for parts. The engine in this one is from a donor car.They both still have distubtors but they must be cleaned good to make them servicable. By trade I am a ex-aircraft mechanic. ANAL FAA HANG OVER ! Looks like you want me to make a dual point out of one, yes/no? How about swap out to electronic? Naw . . . The car had A/C when I took it in but I have ripped out all A/C back to the firewall. I will have to check on ignition advance relay and wiring. I do have a Hanes Manual and a Alfa Bible.You just tell me my next step @ [email protected].

PS. My home "Piscataway N.J".

Thanks jetsetrj
 

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Looks like you want me to make a dual point out of one, yes/no?
No. I'm not offering an opinion on which ignition system to use. Just wanted to know which system you have to aid in the diagnostics.
Did you receive the diagram that I sent?
In pics 2 & 3, what color is the non-white wire on the coil negative terminal? (the white wire is the tach signal) Also, in the last pic, there is part of a device visible behind the coil. Is there a vacuum hose (or a provision for a hose) on this device? If so, it should be the ignition vacuum switch as shown on the wiring diagram.

Whether you have a single or dual point dizzy, the operating principle of the primary circuit is the same. The primary circuit can be divided into two parts; the circuit to the coil positive (hot side) and the circuit to the distributor (the switching or ground side). When the ignition is on, current flows to coil positive and if the points are closed, current then flows through the coil to ground. When the points open, current stops flowing which causes the magnetic field in the coil to collapse which induces high voltage at the coil secondary terminal (in other words, it makes a spark)
Your coil positive side shows about 12V so this half of the primary would appear to be okay. What's next is to determine if the points are switching the circuit to ground. This is where knowing which ignition system you have would be helpful.
 

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Just a thought .. If somehow the points holding screw in the dizzy has loosened or stripped, points may not open and close for firing. This would fit the coil not "delivering" fault scenario. Quick (lucky) fix if this is the issue. Take a look.
 
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