Please don’t tell me to search. I’ve searched until my eyes BLEED and my head HURTS!! Everybody says test the coil and the igniter but I can’t find any info on actually testing the igniter. Page 23-80 of the Helm manual shows me how to check for the voltage coming into the igniter, and I did that, but it never says how to test the igniter itself. Step 7 even says “If all tests are normal, replace the ICM.” HUH?! I’ve also got the Haynes manual and it ain’t much better.
There are no tests to check the igniter itself with out very sophisticated electronic equipment. All you can do is check all the systems and components leading to the igniter. If every thing else is good the igniter is bad. Best to replace it with a borrowed one or spare. They go bad regularly so having a spare on hand is not a bad idea.
If you have access to a digital storage oscilloscope, you can test it. If you need direction on this, email me.
In basic terms, almost all Hondas waveforms on the distributor’s inputs look the same. You need to test the waveform of a known ‘good’ signal and compare it to your’s. If they match, you don’t have a problem with your ignition signaling. Keep in mind that your dist. used three primary sensors to operate properly and deliver a well-timed spark – i) crankshaft posit. sensor; ii) top dead cent. sensor, and a cylinder sensor (I think). You want the signal to be damn near 8V at about 2k rpm to be a good signal. The catch is that you need to be able to monitor the voltage across time and for this you need an oscope. The resistance of the field (primary and secondary) windings test has proven to be inadequate for dignosing Honda ignition irregularities. It will let you know if a shorted winding is the problem but it won’t tell you if the sensor inputs are within spec. across time. As a quick test, when the rpms have been reduced, the voltage on the input sensor should drop also.
If you really want a quick way to test your entire distributor and it’s sensors, etc., get a friend to swap with you. The last time I put one on, I think it took maybe 10min. – maybe less. The old one was still almost too hot to touch by the time I had the replacement running… lol, Sometimes a bad bearing will cause the crankshaft. pos. sensor to overheat and loose it’s ‘magnetism’. Diagnosing this kind of problem without an oscope is next to impossible. If any of you are really interested in this stuff, I have some good references, etc.
I would like to thank the good folks at Tech2Tech, Tektronix, and TPI for shedding some light on some of these issues that have plagued many of us for years…
HTH
Andrew.
aka neex.