'83 SC No CDI Noise, No Start: Trobleshooting and Options

Gordo2 · Gordo2's Garage

My car wouldn't start after a short run today. Fortunately it was parked in front of my house vice out and about (optimist... only could have been better if I had parked it in the garage).

Im not getting any CDI noise when the key is in the on position (it normally whines). I'm assuming my CDI unit failed. BBS search seems to indicate the easiest way to test it is by installing a working CDI. An other suggestions to confirm if it is a CDI unit failure (potentially expensive troubleshooting method)?

Other topic: Replacement options.

I'm planning a motor rebuild in the next year and would like to improve the performance (thinking big: 3.2-3.4 displacement increase, higher compression pistons, twin plugs & PMO's). If I replace the Bosch unit with the Electromotive Tec III (single plug) now, will it be an easy upgrade to twin plug when I rebuild the motor in the future?

Thanks, Gordo

Early_S_Man · 07-01-2004, 11:30 AM

Gordo,

Below is a colored schematic diagram I posted a couple of years ago of the relevant parts of your electrical system ...

I suggest removing the 6-pin plug from the CDI unit and checking for any corrosion or discoloration on the Faston terminal connectors ... then cleaning with stainless steel toothbrush-style brush and vinegar/Q-tips ... followed by rinse with distilled water, followed by 90% isopropyl alcohol. If corrosion found on wiring harness 6-pin connector ... then remove CDI unit and clean male terminals on bottom of CDI.

A multimeter can verify that you have +12 Volt power at the large Red wire at Terminal #15 of the 6-pin CDI connector when the ignition switch is on. Dirty connections are actually more likely than a CDI unit failure!

Superman · 07-01-2004, 11:40 AM

When it comes to this kind of stuff, Warren is "The Man." I'm just surprized that he did not suggest, after all that cleaning of the terminals, that a thin coat of silicon grease such as Dow Corning 111 or 112 be applied. This would essentially preserve and protect those terminals from future corrosion.