Testing optispark off the car

[Epro]

Hi guys, earlier this year my car wouldn't start if it was raining out. I foolishly paid a mechanic to diagnose my car.

His diagnosis from spraying water on the distributor while it was running, was that the cap was no good. Dead with apparently only 600 miles on it.

I get my car back and the issue is STILL THERE. I recently replaced my wires with an OTVC setup and now it appears to be fixed!

I believe his diagnosis was wrong and I want to prove him wrong because I want my money back on labour, and to maybe sell my old MSD unit to make some money back.

All of the off car tests I found were for testing the sensors. I need to test the cap!

[Injuneer]

You could easily test the continuity of each circuit from the internal button to the corresponding spark plug wire terminal. But that's just a superficial check. The critical property of the cap is the dielectric strength of the material that the internal conductors are embedded in. You would have to determine whether the wires are effectively insulated from each other while exposed to a potential of something like 50,000 volts, and that would be problematic to test. Did you check with MSD to see if you could send the cap back to them for testing?

[Epro]

You could easily test the continuity of each circuit from the internal button to the corresponding spark plug wire terminal. But that's just a superficial check. The critical property of the cap is the dielectric strength of the material that the internal conductors are embedded in. You would have to determine whether the wires are effectively insulated from each other while exposed to a potential of something like 50,000 volts, and that would be problematic to test. Did you check with MSD to see if you could send the cap back to them for testing?

No I didn't, but I'm in Canada and wanted to avoid shipping to the states... I'll fire an email off to them and see what's up.

[Epro]

MSD said it was not possible to test just the cap. They also said something along the lines of using the proper o-ring when installing the distributor. I don't remember there being more than one possible o-ring to install in the box? I guess using the wrong one can cause sensitivity to moisture. I don't think he realized that it was an optispark I was inquiring about, and not a typical HEI distributor. After the phone call, I asked him to email the info we discussed so I could post it up.... been a few days, haven't received that email yet.

[Soxxpuppet]

I would call back MSD and try talking to another technician. They might actually know what your talking about. Its worth a shot IMO.

[Ugod02010]

I agree u prob just got a person who all they know about cars is what there computer in front of them is telling them. I thought the orings really only kept oil from dumping out your timing cover. The msd opti is supposed to be sealed very well. Unless by oring he meant the big ass gasket around the cap?

[downrise14]

I had an MSD opti crap out right around the 500 miles mark last fall. I told my friend there was no way it was the opti. I was wrong. Just wanted to let you know if it is your MSD your not alone.

[Spartan7]

The tech could have been referring to just their cap/rotor. The kit comes with a couple o-rings, and if memory serves right they are different sizes. It's been a while since I've had it apart so I can't say for sure.