CSI Ballast resistor question

[Horsepowerguy]

Hey guys! My name is Andrew, and you can see me in this pic:

I'm the guy at Horsepower Enterprises who's been doing most of the work on Psychrunner's CSI. I've done a good bit of research in the archives, tech articles, and photo gallery for his car, so I thought I'd come back to you guys for this one.

I have been unable to come up with any wiring diagrams for this car, even in our extensive "library", as we like to call it, of shop manuals. I'm having some issues with getting solid spark. I installed the Pertronix setup, and have double and triple checked all the connections with that. The car ran before the body work, etc was done. Now it just loads the plugs up horrendously. I even pulled the supposed fuel pump fuse (#7 according to the photo copied manual with the car), and it still loaded the plugs. Seems like it wants to fire in the start position while the ballast is being bypassed, but as soon as you let it back to run it dies. Also, if left in the on/run the ballast actually starts glowing!

So, the ballast has two pins on one end, and a single pin on the other. As I found it the two-pin side had a green (12V switched ignition) and then a white, which leads back into the wiring harness. The single pin end was connected to the black w/red tracer that goes to the coil positive. Can you guys confirm this is the correct setup? Also, can anyone help me with the fuel pump fuse? I find it hard to believe the fuel pump runs off an 8A fuse.

Thanks a bunch, and this car has been a blast to work on!

 

[Horsepowerguy]

Well, we figured out our issue. There seems to be an issue with the wiring in the new starter, Bosch p/n SR71X, in the circuit that powers up the 12V signal to the coil during cranking. The reason the ballast was getting so hot was because it was getting voltage at both ends. I'm just glad this didn't damage the Pertronix unit!

So, now my question is this, how important is it for the coil to get 12V during cranking? The car starts and runs fine without that signal, can I just leave it disconnected and terminate the wire?

 

[Malc]

The voltage at all components tends to drop when cranking the engine. However the engine should fire if it drops to around the 10 volts level. Anything less that that and it may not work.
Malc

 

[gazzol]

I had a problem a number of years ago after fitting my car with a 3.5 ltr engine and injection system including the ignition system from an E12 M535. I wont bore you with the ins and outs but I traced the problem down to the E12 ignition amplifier (which also fed the coil) and I was only getting 5 Volts at the coil when the motor was running. I chopped out the wiring for the Bosch amplifier and wired in a Vauxhall (General Motors) unit and wired the coil with a 12Volt feed and carried a spare coil incase 12 Volts fried it. It never did and I have travelled over 240 miles in one day on a number of occasions.
My point is why not throw the ballast resistor away and run the coil 12V you'll get a better spark aswell.

 

[Philip Slate]

You can also replace the coil with a Bosch Blue unit which is designed to work without a ballast resistor. If you want the look of originality keep the ballast in place and just connect some dummy wires.

 

[Horsepowerguy]

Well, we swapped the original starter back in and things seem to be working fine, now. I'm leary of removing the ballast not so much for the coil, but because the Pertronix instructions say to retain it, if so equipped, but I would tend to agree that their reasoning is for coil preservation. This is the first the car has run in a while, and there's still quite a bit that will need adjusted, tweaked, and replaced, I'm sure. Thanks for the input, guys!