Performance test for CD box?

[Christien]

Is there any way to test the performance of my CD box? I know it's working in general - the car starts, runs, drives, etc. But when I'm at the track, running at constant high rpms, after about 5 or 10 minutes, I'm noticing a gradual but quick decrease in horsepower, to the point where after about 15 minutes on track I can't get above 5000 rpm in third gear on an uphill incline. I had a local shop owner/racer do a couple laps and he said he was pretty sure it was the CD box on its way out.

Is there any way to confirm this, without just replacing the CD and coil? I'll do that, and happily, but I've been chasing this problem from carburetors to fuel delivery to throttle linkages, etc. and I'm getting sick of throwing money at the problem and missing the target.

Thanks!
Chris

[Gunter]

That's easy, Chris.
Buy a used Bosch CDI module and swap.
I assume it's a 3-pin? They are cheaper than the 6-pin.
How is the green wire?

[Christien]

Yes, it's a 3-pin (at least according to the guy who looked at it - I've never looked at it closely myself).

I'm going out to do some work on the car in about half an hour - what should I look for on the green wire?

Thanks!

[Early_S_Man]

3-pin CDIs don't have a green coax or wire.

You can find in-car and bench check procedures in the Bosch Test document in the following thread:

History of Bosch CDI ... toubleshooting info, parts list changes, and schematics ...

[Christien]

Well, I just went and pulled it all out and put it back in. Definitely a 3-pin - green (could be blue), black and red in a rubber sheath that clips onto the bottom of the unit. There was also a single wire on a clip on the front - ground? Thing is, there were two clips on the front, one in front of the other, and there's only one wire (female end) to attach to it. Once I got everything back together I started the car to make sure it runs, and it did fine.

I opened up the CD box, and everything looked ok inside. In fact, I was surprised how clean it was. I took a pic but haven't transferred it from the camera yet - I'll post it once I do. I didn't mess around with anything in there because I didn't at all understand what I was looking at and didn't want to screw anything up.

Warren, thanks for posting that link - I had a quick look but don't have time to read through it all right now, but I'll read it all very carefully later tonight.

[Early_S_Man]

Chris,

The wire to the 'A' terminal [goes to the + side of the coil] should be Blue/Yellow striped. Red is your +12 Volt power lead, and black is the trigger from the points. There are, indeed, two folded-up 0.25" Faston tabs for ground on the 3-pin CDI unit's case, and only one wire to attach from the harness with a (female)Faston. There should also be another brown ground strap under one of the bolts holding the CDI case to the relay panel, and it should go to a bare spot on the fender to be grounded!

[Christien]

Thanks, Warren. I'll double check the colours tomorrow. There was indeed a ground strap fastened behind the CD to the panel, going to a ground about a foot away.

Looks like I might have a line on a Permatune, so hopefully I'll get that swapped out this week then test it at the track this weekend.