MSD Rotor phasing

[RodKnock]

Thanks guys, I'm 99.99% certain that I don't have a crank trigger, and the wires coming from that "black spirally thingee" go somewhere. I'll be in the garage on the weekend to confirm. I was "getting on it' fairly hard, so I may have hit the rev limiter, but I plan to check it out in more detail this weekend.

The photos really help. Gracias.

[Eljaro]

Originally Posted by RodKnock View Post
Here's a dumb question. How does one know if he or she has a "crank trigger" system? I'm running a 8594 MSD Billet distributor and a MSD Digital 6 ignition, but now I'm curious, and would like to check my rotor phasing and I know that "crank trigger" systems are treated differently according to the MSD instructions.

The 8594 Distributor has the trigger system inside, which is the magnetic pickup and the reluctor which give the signal. The cable coming out goes to the MSD box.
The problem here is that MSD is supposed to deliver the distributors with the mag pickup properly aligned so as to produce a spark when the rotor point is perfectly aligned with the corresponding post in the distributor cap.

In my case and probably in some others the rotor point and the post in the cap do not align when the spark jumps and that created some disturbing hesitation at full advance, because as I have seen while checking the problem and the spark, the spark jumps at the leading edge of the rotor point at idle but changes to the trailing edge when rpm rises.
Anyway, the only thing you can do without having to purchase the MSD rotor phasing kit (they make it because some problems with rotor phasing DO ocurr) is to move the magnetic pickup in the opposite direction of the position of the rotor towards the cap post. You have to remove the glue MSD puts between the mag pickup and the distributor housing and you can move the pickup slightly back and forth, which is what I did and solved the problem. Now the point and post aligh perfectly and the hesitation is gone. You can check that also with the timing light, as the timing will get erratic at full advance.
If you have crank trigger the problem is solved just by moving the trigger in relation to the magnet and /or rotating the distributor.

So checking the distributor phasing with a cut up cap is not to be excluded if you have some hesitation problems, which also show up if under your timing light the mark on the crank pulley is not absolute steady at full advance.

[RodKnock]

Originally Posted by Eljaro

The 8594 Distributor has the trigger system inside, which is the magnetic pickup and the reluctor which give the signal. The cable coming out goes to the MSD box.

I'm confused now. So I do have a crank trigger system, but it's not located on the balancer, but inside the distributor? I'm going to have to read again, and then read again, Eljaro's post, since my less-than-technical brain is having a difficult time understanding it.

Assuming I get the time, I'm going to check the rotor phasing and the rev limiter. BTW, Patrick thanks for photo. I do remember the back side of the Digital 6, but your pic makes it crystal clear. Now, I just need to contort myself under the dash to see what it's set at.

There can be a dozen reasons why it did what it did and one of them could the fact that I ran out of gas two weekends ago and the fuel pump may have sucked up something, but that's hard to believe with a relatively new tank and car.

[patrickt]

Originally Posted by RodKnock

I'm confused now. So I do have a crank trigger system, but it's not located on the balancer, but inside the distributor? I'm going to have to read again, and then read again, Eljaro's post, since my less-than-technical brain is having a difficult time understanding it.

NO, NO, NO. You do not have a crank trigger. You have a regular magnetic pickup in the distributor like everyone else. Quit thinking about a crank trigger, you don't have one. Put it out of you mind. It ain't there.

[RodKnock]

Originally Posted by patrickt

NO, NO, NO. You do not have a crank trigger. You have a regular magnetic pickup in the distributor like everyone else. Quit thinking about a crank trigger, you don't have one. Put it out of you mind. It ain't there.

"Am I clear?"

"Yes, crystal clear."

So you're telling me I have a crank trigger system right?

[patrickt]

Your crank triger is right next to your Nitrous Oxide bottle (which is probably behind the chair in your office).

[RodKnock]

Originally Posted by patrickt

Your crank triger is right next to your Nitrous Oxide bottle (which is probably behind the chair in your office).

How did you know I was a dentist?

[mrmax]

Who's on first?

[patrickt]

Originally Posted by mrmax

Who's on first?

No one; I just rounded the bases.

[patrickt]

Originally Posted by RodKnock

I was "getting on it' fairly hard, so I may have hit the rev limiter, but I plan to check it out in more detail this weekend.

I'm just pleased as punch that you're "spreading your wings" in to the mechanical side of your Cobra (that can be as much fun as driving it). Since you have a hydraulic cam, it's possible that your rev limiter was set by the engine installer at a low number, maybe even 5000RPM or so. You can't miss it when you hit the rev limiter in an MSD unit. It's as obvious as the nose on your face -- it's like kidney stone pain or trying to go through a revolving door that is securely locked down. I mean it; it's that obvious. That being said, crawl under the dash and look at the side of your Digital 6 box. You will see two sets of dials. Only one of them will be important to you (I can't imagine you have the blue line enabled for your 2 step limit). Look at the dial on the right and read the little pointers in the middle of the circular clock for both 1000's and 100's and that will tell you your rev limit. Here's a pic from the manual: