Droops83

In that case, it might be easier said than done, and the ease of doing so is entirely dependent on where the MSD box is mounted and how the wiring was modified. If wiring was cut/spliced/soldered, then it might not be super quick and easy to change it back to stock. When I have installed MSD boxes, I take the time to ensure that it is "plug and play" and can be easily wired back to stock configuration.

The MSD website has PDF documents showing the various wiring configurations depending on the type of ignition/trigger system used. If your MSD box and its wiring are easily accessible, you might be able to see where the factory positive and negative primary ignition wires are connected to the MSD, and maybe you'll be able to run them straight to the ignition coil.

Otherwise, I could mail you the ~20-year old MSD 6AL box from the '74 Jensen Healey that I am working on, the car had it mounted when I bought it and I don't plan on using it (I'll make sure to test it).. I also have a couple of other MSD boxes lying around my shop that I can send if I can find them and you cover postage. PM me if this would be easier than converting wiring back to stock.

spencang

Ok, box and blaster 2 coil are good. I did more research on testing the box and the MSD rep in the video said the wrong thing; the ignition switch in the car should be on, not off. I did this and it tested out right. Which makes sense because I can start the car, etc.

so now I'm moving on to the cap and rotor. I did notice that when I was removing the coil wire, the bottom of the cap was pulling away. It appears that when it was changed 18 months ago, the bottom screw/fastener was NOT screwed all the way in. I'll report back with pictures once I take it off later today.

Droops-thanks for the information and the kind offer; I appreciate your willingness to help.

spencang

how's my cap look?
how's my rotor look?

spencang

Spark plugs 2-4-3-1

GPA951s

Just Curious, I see you have a Tial WG but is it a dual port? I have had this issue before in my car but I was running (And still do on my street car) the Autothority MAF with the banjo Bolt Jetted. I sort of made my system. When I "Made" the jet I patterned it off the original but I knew if I made the orifice smaller that I would get more boost. What I found was, with that amount of boost when the temp got below 45 degrees that problem would rear its ugly head.... Also Every spring when I got the car out for the first time this happened. What was happening is that when the temp got low more Dense air the car would sense a knock . This also happened in the spring because my high octane fuel was now low octane... and it would knock as well... So Every spring, I run the fuel out and filler it up with good stuff and never had that issue ever again. Much like an old 70's car when the motor is "Lugging" it knocked... I'm not saying that's your issue but it sure sounds familiar.

spencang

I ordered a new cap and rotor from rennbay and I'm getting new spark plugs. I should have it all re installed by midweek next week (I'm going out of town for a couple of days), and I'll report back.

spencang

Yes it's a Tial dual port wastegate. I've had the wastegate for years, prior to this problem. But it's install was the beginning of several issues, mostly mechanic(s) related though...

If the new parts don't fix it, then I'll go down that path. Thanks for the advice.

Tom M'Guinn

Yeah, if new wires fixed the same symptoms last time, I'd be inclined to change the cap, rotor and plugs too. You removed one weak point, only to reveal the next weakest a short time later, would be my guess. The MSD box is hard ignition parts. With mine, I change the cap, rotor, plugs and wires more often that I'd like to admit... When the ignition starts getting weak, I just turn down the boost as needed to avoid the stumbling until changing ignition parts.

Also, it's hard to tell from internet pictures, but the side electrodes on a few of those plugs do look worn away.

spencang

Tom- thanks for the input and making me feel like I'm on the right path to figuring this out. I'll let you know as soon as I know.

spencang

I installed the new spark plugs (ngk iridium X gapped to 0.32) new cap and new rotor and so far so good. The bucking at 3800 rpm is gone. I did a few runs in 3rd and 4th starting from 3000 rpm, which is exactly how it manifested itself before.

I noticed that the top screw latch on the old rotor was on tight but the bottom one was not. That's why there's a mark on the rotor as seen on the picture that was probably caused by vibrating under load.

If the symptoms come back, I'll repost. But for now, all is good.

Tom M'Guinn

spencang

Will do with the plugs. Any reason why the Iridium plugs are not as good a choice?

Tom M'Guinn

spencang

So I took it on some more runs in 3rd and 4th today and then on a 4th gear pull at 4200 it did it again. Then I heard a whine that sounded like when I tested the the MSD, only constant. I checked the cap and the top screw was loose. I retitghtened, turned the boost to 14, and drove him with no problems. But the whine was still there.

This picture is what I found when I took the cap off. After inspecting the cap and rotor and making sure that I was sent the right cap and rotor, which I was, I am thinking that the old rubber gasket must be the culprit.

Any other possibilities?

spencang

And Thom, thanks again for information on the spark plugs