Is my coil weak???

I thought I would do a resistance check on my coil even though it is pretty new, because I'm having the same old misfire issues and I'm still stumped.

I measured 1.3 ohms pin to pin (Good) and 10.6K (Spec in the Haynes is 11.3 minimum and anywhere from 13-15K max) positive to terminal.

Should I replace the coil and give it a shot considering the resistance is on the low side?

If so, what brand should I buy and where???

Thanks,

Bryan

MSD has a direct fit and they hold up good. I'm running one with a MSD 5200 control box. Had on my other jeep now on my 97 cherokee sport. Dale

So, would you recommend a change with that resistance measurement? 10.6K is not too far off the low end of the spec, but I'm guessing when it heats up, the resistance could reduce even further. Who knows?

Just seemed like a possibility and it's much cheaper and easier to change than the CPS.....

Bryan

Dale,

Do you know the part number of the direct fit MSD coil itself? I'm guessing it would still fit a 1996 JGC 4.0 I6??

Do I just need to order direct from MSD?

Bryan

http://store.summitracing.com/partdetail.asp?autofilter=1&part=MSD%2D8228&N=4294890813+4294908280+115&autoview=sku Here is the page from summitracing.com. You can check it out. Some of the other dealers prices are higher. Dale Questions holler

I ordered one last night, should get it tomorrow. I will post the results for everyone this weekend after I drive it a bit. Sometimes it takes a couple of trips for the problem to resurface and I don't want to jump the gun.

Thank for the help!!!

Bryan

Well,

I put the new MSD coil in tonight, but first indications are that I still have a problem and it is eventually going to misfire again, if it hasn't already. My idle is still a little rough in spots and I can see the TAC fluctuating as it did before when stopped and in gear. Not as much vibration in the Jeep, but it defiantely happening. Steady as a rock in PARK.

When I'm driving though, it almost seems like it's a Hall Effect device that is shutting down for a split second. But I really need to take it out on the highway to be sure.

Funny thing is, I have been leaning toward a crappy CPS all along (with previous posts) and it is starting to show symptoms of occurring more often now. Quick bursts of RPM or a quick drop and then back to stable again. I really wish I had the confidence to dig out that CPS (I'm still not sure it's even the right one because I can't see it well enough) and just change it myself. If it's not that, I'm REALLY going to be lost.

Are there resistance measurments I can perform on a CPS to give me an idea?

Because it is quick, I'm going to reinstall my new IAC valve tomorrow just to see how it acts with a higher quality coil.

If anyone has any brilliant ideas, please pass them along. Tomorrow and Sunday will be sunny days and plenty of time to work on this puppy....

Thanks for the help....

Bryan

Well...the coil wasn't the problem...at least not the problem causing my misfires.

Though my idle does seem to better (especially after its warm), the main problem I have been having seems to still be there as I said in the post yesterday.

A couple of "surges" and sluggish on accellerations at various times....

I would expect my CE Light to throw a code at some point, but it hasn't yet. Then, it will likely be the saem "43" or P0300 general "Mult cyl random misfire" code.

This sucks. I'm at my wits end. The good part is that I really haven't spent any unnecessary $$$$ because everything I have done was either needed or will improve the performance once I find the root cause....Also, it must be a failing or internittent part because this has been going on since December and nothing has completely failed since I changed the origianl CPS.

I guess I'm going to have to try and crawl under there and see if I can find how the CPS is mounted and make sure it is the right one. My "gut" has always told me that this is it....If I can get a picture of it, I will try to get it posted and see what others think....until then...I'll take any suggestions I can get...

I have been over all of the wires and everything obvious and nothing is jumping out anymore....

Bryan

Well...the coil wasn't the problem...at least not the problem causing my misfires.

Though my idle does seem to better (especially after its warm), the main problem I have been having seems to still be there as I said in the post yesterday.

A couple of "surges" and sluggish on accellerations at various times....

I would expect my CE Light to throw a code at some point, but it hasn't yet. Then, it will likely be the saem "43" or P0300 general "Mult cyl random misfire" code.

This sucks. I'm at my wits end. The good part is that I really haven't spent any unnecessary $$$$ because everything I have done was either needed or will improve the performance once I find the root cause....Also, it must be a failing or internittent part because this has been going on since December and nothing has completely failed since I changed the original CPS.

I guess I'm going to have to try and crawl under there and see if I can find how the CPS is mounted and make sure it is the right one. My "gut" has always told me that this is it....If I can get a picture of it, I will try to get it posted and see what others think....until then...I'll take any suggestions I can get...

I have been over all of the wires and everything obvious and nothing is jumping out anymore....

Bryan