Ignition Help Needed

[AManNamedNoah]

Good Afternoon,
I am looking for some advice as to what I did wrong in setting up my ignition coil/module. Recently, I replaced what I thought to be a broken ignition module, however, this was not the case. The owner before me had an XR3000 installed and in order to bypass the resistor, decided that backup lights weren't necessary, and used that wire to give him the power needed for the coil. The problem turned out to be that that wire was only getting 8 volts instead of the 12 needed. Because I thought the problem was with the module, I now have a XR700 installed with a new non high performance coil with the power coming from a wire I found under that car that got 12 volts while the car was ON. Because this new module requires a resistor I spliced into the wire that is getting 12 volts while ON and ran that wire through a ballast resistor onto the positive terminal on my new coil. This worked for a while, until that cold front came in and my car would no longer start. I checked the module and while turning over, the light was flashing indicating that it was firing, I also checked the spark plug wire going from the coil to the distributor and there was also a spark To get home, I had a few friends push me so i could pop the clutch and get home. On that trip home, the car ran fine, except for the fact that it wouldn't last more than 5 seconds idling with no gas (could be due to the car not heating up or that another carb tune up is needed). With all that being said, here are my questions. I would like to run a wire from the starter solenoid to the coil like the car was stock, however, when I put the car in the ON position, I'm not getting any voltage coming out of the solenoid; is the coil only supposed to get power while it's trying to start or is there a problem in my wiring to or from the solenoid? What I think is the problem is that the car needs 12 volts to start and only 8 or so volts while running. Thanks

[bbodie52]

The XR-700 is normally marketed by Crane Cams. It is an optical trigger system used to eliminate the ignition points and has a good reputation. It is somewhat unique in that it DOES NOT REQUIRE a full 12 VDC to operate the electronic circuitry in its system. It was designed to operate on the reduced nominal 7-8 VDC normally expected in a standard ignition system wiring that includes a ballast resistor or resistor wire in the circuit. In fact, the installation instructions specifically warn that the electronic module may overheat and may begin to malfunction if it is powered with a full 12 VDC source.

1963 Ignition Wiring Diagram

1964 Ignition Wiring Diagram

Your ignition wiring should duplicate the original 1963/64 Corvair wiring, to include the original resistor wire. If that has been removed, an aftermarket ballast resistor will have to be substituted. Note that the attached Crane Cams instruction sheet covers both the XR700 and the XR3000 systems. If you examine the instructions you will find that ONLY THE XR3000 IS DESIGNED TO OPERATE WITH THE BALLAST RESISTOR BYPASSED. The XR3000 module uses a full 12 VDC power source, while the XR700 is specifically designed to be connected to the standard ignition wiring that includes the resistor wire or ballast resistor. The XR700 is designed to be powered by the lower 7 VDC provided through the ballast resistor or resistor wire. It will overheat if it is wired to 12 VDC and will begin to malfunction with the higher source voltage.

I have looked back through your previous posts and I cannot find a full picture of your engine compartment. I can see that your engine does not use the original Rochester carburetors. If it is a non-turbocharged engine with some kind of center-mount carburetor, your cold weather operating problems are likely due to the cold blooded center-mount carburetor setup. It may lack an adequate choke setup to optimize it for cold engine starting. The normal choke system enriches the fuel-air system during cold operation, until the engine is fully warmed to normal operating temperature. The choke system includes a fast idle throttle system to increase the idle speed when the engine is still cold. The other problem with the center-mounted carburetor is an inherent lack of engine heat reaching the carburetor. Corvair engines with center-mounted two or four-barrel carburetors have a carburetor that is isolated from engine heat. In very cold operating conditions, the carburetor will never be heated adequately and will likely run poorly. (There is a metal cover plate near the oil cooler, below the generator area. Removing the cover plate in the winter will allow some additional engine heat to circulate into the engine compartment, and may heat the engine compartment enough to help the cold center-mount carburetor somewhat).

Winter-Summer Cover (3).jpg (59.17 KiB) Viewed 216 times

Winter-Summer Cover (4).jpg (63.83 KiB) Viewed 216 times

The standard Rochester carburetors include a good choke mechanism and receive adequate engine heat because they are physically attached to the warm intake manifolds on the cylinder heads. (Some Corvair owners who use a center-mounted four barrel carburetor in cold climate conditions have corrected the lack of engine heat to the carburetor by modifying the carburetor manifold to include a chamber welded to the bottom of the center-mount system. This chamber is attached to a oil line to circulate hot engine oil through the manifold to heat the carburetor).

I would like to run a wire from the starter solenoid to the coil like the car was stock, however, when I put the car in the ON position, I'm not getting any voltage coming out of the solenoid; is the coil only supposed to get power while it's trying to start or is there a problem in my wiring to or from the solenoid? What I think is the problem is that the car needs 12 volts to start and only 8 or so volts while running.

The starter solenoid only provides a full 12 VDC to the ignition circuit when the starter is cranking the engine. The voltage boost discontinues as soon as the key is released and the starter disengages. The 18B wire at the firewall side of the 10-pin multiconnector is a source of 12 VDC before it passes through the resistor wire. Tapping in at this point will provide full battery voltage that is controlled by the ignition switch when it is in the ON position.