Hopefully the last no spark issue ever

[beav350]

I am SURE that your starter is the problem. Although I cannot think of any previous scenario where this was an issue, the only thing that could trigger the CPS inadvertently would be if the starter solenoid was shorting out through it's case ground & triggering the CPS, which obviously is what is happening based on your starter pinion speed/spark speed. You removed the starter to replace the flywheel, did the plastic case of the solenoid crack? Check it, replace if neccasary, or try to borrow one for an A/B test. This is the only thing I can think of...

 

[oldie eye]

I can't believe it. I swapped the strter & it works. I have the proper spark. You were right, & I am so happy now. I don't know how you reached that conclusion, it makes no logic at all, but it worked. I NEVER would have reached that conclusion on my own. I've nbever heard of or thought that a functioning starter could mess up spark, but somehow it did. All the flow charts & common sense about checking the CPS & ignition wiring in the world wouldn't have led to that answer. That is one to keep in the mental file regarding bizarre diagnostics. Great job, Beav350, & thank you so much!!!!!! Now I can get a good nights sleep.!

 

[beav350]

No problem, glad I was able to help, actually it kept me boggled for awhile. Yes, it is bizarre, & now officially this problem can graduate on to the NO-SPARK/wierd spark posts. No one I spoke to has ever heard of it, so it must not happen very often.

 

[XJXJ]

No problem, glad I was able to help, actually it kept me boggled for awhile. Yes, it is bizarre, & now officially this problem can graduate on to the NO-SPARK/wierd spark posts. No one I spoke to has ever heard of it, so it must not happen very often.

Excellent news and gold star for Beav350. OP - 'Sorry my lame ideas didn't work but you asked & I tried. 'Hope you can at least appreciate the time/effort.

 

[dizzymac]

I think it's cool that so many ppl wanted to help....fellow XJ'ers coming to the rescue....after all isn't that what this forum is all about, and lets face it, we all learned something from this post.

 

[oldie eye]

Just to conclude the thread, I did indeed have somekind of misalignment w/ the starter/flexplate/CPS. I swapped the flexplate with another one from the same manufacturer, (different source, & twice as expensive though) & now it works fine. New starter, new flywheel. There was some very strange damage to the previous/new flexplate. On the ring gear side of the little windows that trigger the CPS, it was worn down pretty good, as if either the CPS or starter pinion were grinding it down. The GM style starter does not allow the pinion to slip past (rearward) the ring gear, so I don't think the pinion could have caused it. The CPS isn't tough enough to grind away part of the flexplate even if it was somehow able to contact it, due to misalignment of the flexplate, etc. The CPS has no damage. So I don't know for sure where it came from, but I'm happy that it works now. I did only have one upper bellhousing bolt in, but the engine/trans. seemed aligned enough for everything to work without interference. The best sympton I had to point at the flexplate/CPS/starter was the fact that I only had spark trigger once for each engine RPM, instead of 3 times, so it's possible that the flexplate was slightly egg shaped. Who knows?!!