Okay, here's a good one to think about, ignition "problems". What I have - MSD billet distributor magnetic pick-ups (2) at 180 degrees apart (dual ignition), mounted inside a Ford Escort distributor (Dura-Spark II) retaining the stock reluctor. The pick-ups are connected to a GM 4 pin ignition module (Accel) and then the modules control Accel coils. So far so good. Now, the systems are wired exactly the same both from the pick-ups to the modules and from the modules to the coils. With ignition A running we have advance like we should have (vacuum and centrifugal). With ignition B running we have nothing, the spark is 45 degrees (90 crankshaft degrees) out of phase. The ignition is firing between the distributor towers, not on them.

Diagnostics:
1. Drilled ½" dial holes in the top of the distributor cap so I could shoot the timing light into cap and see where the rotor was located at each spark. Verified ignition A is dead nuts on, ignition B is 45 degrees out of phase.

2. Pulled the entire system and ran the distributor on the lathe, the findings from the engine repeated themselves.

3. Switched modules and pick-ups (pick-up A with module B, Pick-up B with module A). Ignition B still 45 degrees out of phase. Note, color coded wires are connected identically on both ignitions systems.

4. Everything "appears" to be identical

5. Reverse wires in the pick-up side of the module - Hey, wait, ignition A is now 45 degrees out of phase, ignition B is dead nuts on the money.

Solutions?? Ideas?? What do you all think??



Oh yeah, I do know the answer, discovered it the "hard" way. This is just a mental quiz to keep minds off the high price of gas. North East Philadelphia (PNE), 100LL avgas - $3.07/gallon - plus tax.

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Speed is relative - until you hit something

Well, you've got my curiosity aroused! --------- You didn't say how many cylinders you're running, or if the distributor is for a 6 or 8 cyl engine. ----- If it's for a 6 cylinder, I believe your 180 degree spacing will be out of phase for firing simultaneously, if that is what you are trying to achieve. ----- If it's an 8 cyl distributor on an 8 cyl engine, the wrong reluctor may be installed. ---------------- I'm also wondering about your reasons for having such a system. Is it to have a "back-up" system? Or....??????

Bruce,

Good points, actually the number of cylinders doesn't matter, but for the sake of informaton I have a 4 cylinder. When you use the timing light with the cap completely off on ignition A the coil fires when the reluctor is aligned with the pick-up (like it should), on ignition B the coil fires when the reluctor is 45 degress put of position (fires between the reluctor poles).

If we had a 6 cylinder the engine wouldn't run worth beans as the spark would still be between the towers on the cap. For an 8 cylinder we still wouldn't get good running as the reluctor would have 8 posts on it and the firing would still be between cylinders.

By the way, the above are good "hints". I just wish I recognized them when I was fighting with this (now I'm making it TOOO easy).

You mentioned the wrong reluctor, shoot, when I got the engine it had distributorless ignition. I chunked that intot he garbage and installed the Escort distributor. A little filing here, a little there and bingo, we have ignition. Heck, I not only have the wrong reluctor, I have the wrong ignition, but it works. One aside, reluctor shape is critical in some pick-up applications. We have seen that in some of the experimentation that has been conducted. Good thinking, but not the solution.

The purpose for the secondary ignition is for redundancy. The engine is for my Experimental aircraft (read "homebuilt"). It's a Subaru Legacy EJ-22 with dual ignition, Holley carb, reprofiled cams, 160 honest HP from normally aspirated 2.2 liters. When you're 50 feet off the ground and nothing but trees below you that back up is good insurance. Also, by offsetting the pick-ups a tad (less than 180 degrees apart) you can have one ignition for starting and ground operations while the second is used for cruise (more advance).

It's a dirt simple problem, one you could easily reproduce whether you're at the North Pole or the South Pole. I produced it in Tennessee and it took me 4 days to figure it out, now I have the infamous flat spot on my forehead where I repeatedly pounded my head while muttering "DUH" after I discovered the problem. Please don't make it too complex, think about the "basics".

Good Luck!!!
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Speed is relative - until you hit something

Things are so easy once you see. Got a picture?
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Mike J

I have some pictures someplace, but they really wouldn't do any good. I've dragged this out for 24 hours - that's plenty. Here's the solution:

Background: The GM 4 pin module looks for a signal from the magnetic pick-up. The signal it looks for is generated as the reluctor passes the manetic pick-up creating a AC pulse of maybe 2v (exact voltage I don't remember, let's use 2v because it's sounds good). The module looks for the voltage to go positive and then negative - one cycle. As the voltage passes through zero and starts its trek to the negative side of the cycle the module tells the coil to fire (breaks the current much like the old points). The net result is a spark.

Okay, remember I mentioned reversing the wires moved the 45 degree out of phase condition from one ignition system to the other? The signal to the module is reversed in that the signal goes negative and then positive. Hmmm. There is also a lag betwen the signals as one reluctor passes the pick-up and the next one is getting ready to swing past the pick-up. So, the module sees a negative signal, then positive, a lag, a negative signal, a positive signal. Well, the module does exactly what it's supposed to do, fire when the signal goes from positive to negative, it doesn't care about that lag. This lag happens to be 45 degrees out of phase.

Now, I mentioned the pick-ups were wired the same, color coded. I also casually mentioned North Pole and South Pole. Ah, the little light bulb in the brain goes on. If you reverse the magnets you reverse the signal which results in the out of phase condition. After looking at the magnets there is a little white paint dot - barely visible. When the dot is towards the pick-up windings the orientation is correct. It took a phone call to MSD to find this out.

Four bloomin' days of testing and head scratching because I reversed one of the magnets - geez Louise, who'da thunked.

Well, that's my story and I'm sticking to it. Happy cruisin'.
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Speed is relative - until you hit something