Hi rrich, Plenty of spark during the no start condition but it is not blue spark. Kinda white, yellowish.

 

Now we're getting somewhere. And, of course it doesn't start with the CPS unplugged..... I meant if you unplugged it and then plugged it back in.

 

Thanks! I'm leaning towards that as well. I'll see what rrich has to say about the spark also.. Thanks for taking the time to help, I appreciate it!

 

LOL! Ah, Sorry man, Unplugging the CPS and plugging it back in makes no difference, it's a crap shoot. I let it idle for about 10 minutes shut it down and then 5 minutes later it will just crank and crank..

 

I happened to be watching mine in it's last months. Worked seemingly OK down to .3. Then had a no start and a lower reading and changed it. Man! what an improvement! I guess I had gotten use to it running a tad rough, it seemed much smoother and now starts really fast for a Renix. Echlin # css980 (from Napa), is working fine for me btw. Yea, .1 and a dugy spark. Something to take care of anyway, even if one of your injectors is getting full time power.

 

Thanks! Tomorrow I will see if repositioning the CPS will help with the voltage. If not I'll buy the one that you recommend. I'll see what this does to the spark as well. I think I'm getting closer through, thanks to my Jeep peeps! Have a great night!

 

Yea, that CPS signal is king. First thing a doc does is check your heartbeat, and that's it. No timing adjustment, your ECU does it with info from the sensors. Renix is different...it will advance it until it gets a signal from the knock sensor to knock that off. (They don't have knock sensors, just a hole there). We may get way better mileage when the air is wet, or on premium because of that feature.

All I could guess on the rising fuel pressure is that heat migrating to the injectors and lines while it was sitting might do that. Can't say for sure.

There are a couple tricks reaching the CPS. Your feet are out to the right. Your right hand is on the ratchet with nearly a couple feet of extensions down my the trany cross member. With your left you can sort of reach up past the front drive-line to hold it. 11mm socket > 3in extension > swivel > then the long ones. If you tie a long string on the old, you haul up the new with it. Can that plastic thing. DO NOT drop anything in there.

 

Thanks! I took out the CPS, cleaned it and tried to push it as close as possible to the flywheel. I bought the CPS a couple of months ago from autozone and it doesn't have the slots on the bracket so I am thinking about drilling it out to get it closer and see what happens. If that doesn't work I'll go to Napa. Also, I'm kind of a rookie with the voltmeter; the lowest VAC setting on mine is 200, so with it set to that, it is showing 00.1 when I crank it, am I doing this right?

 

Slot the upper hole to look like the photo, so the sensor bottoms out on the bell housing on that side.

Meter scale is fine. You want to see .5 volts AC.

 

Thanks Cruiser, I appreciate it. I'll give it hell tomorrow, ran out of daylight.

 

A white spark indicates a very weak spark. It will have a very hard time starting and running with a weak spark. IT MUST BE A CRISPY BLUE! -- color indicates the voltage.

Check the wires and connector on the coil - then trace the wires back to the ECM. There's a bad connection somewhere - but if you replaced the coil with an aftermarket - especially one from China or Autozone, it's a sure bet it's a bad coil.

The only reliable source of Jeep coils is the Jeep dealer itself - and possibly cheaper too!

I think you'll find playing with the CPS is an exercise in futility - unless of course you got it from Autozone. If you did, you still need a CPS! They only sell Chinese knock-offs - junk!

Get it too close it hits the flywheel and breaks it - and/or reduces the signal . Put 2 layers of duct tape on the end as a spacer to get it the right distance (.008" ?) Good ones come with a cardboard sleeve as a spacer. The cardboard or duct tape gets pulled off in a few revolutions - you'll hear it pull off.
It's just a small magnet with a coil of wire wrapped around it - it's NOT a Hall Effect Device like some say. A Hall Effect Device is an entirely different thing - a semi-conductor switch.

There is a reason the CPS holes aren't slotted and it's not insanity. It puts the CPS in the right position.

I've had almost 100% failure with AutoChina CPS'S.
CarQuest and NAPA is better, but still "iffy. Out of maybe 15 or 18.
I won't use critical parts from them anymore. My customers want reliability, not price.

 

Great info, thanks! yea, I may just go buy the CPS from Napa and be done with that. I haven't replaced the coil or ICM, I had them tested at autozone. I don't remember the exact numbers but he said the coil was right on the money and ICM was a little weak but within spec. Both the coil and the ICM look very old.

 

Mopar, mopar, mopar!

How much is the one at napa anyways? $68 from my local dealership...

 

39.99 at Napa. Made by Echlin ignition parts. The one I bought at autozone was 28.99 made by duralast.

 

Here's a photo of the clearance between the CPS and flexplate. The original drawing I included was from the factory TSB. That's how they supplied the CPSs in the patch harness kit.