More RENIX spark questions (wire colors / volts questions)

[FilthyLlama]

Howdy.

I have a 1990 Cherokee 4.0 Laredo 2 door. Bone stock. I've another thread on hear regarding the CPS, which I have fixed (mostly). I'm getting 0.8 vac on crank from the CPS. 195 Ohms. I've wired it directly through the firewall with it's own new set of wires and fitted it to the computer.

First question: Can anyone tell me which wire colors were A and B on the CPS connector on the wire loom side? I may have switched them around and would like to know for sure.

Second part: I still have no spark. I had spark, ran the jeep for a few minutes, then it just died and haven't had spark since... UNTIL TONIGHT. Went to get some volt readings. Hooked up the battery, had my brother crank the motor and SPARK! Surprised, we grabbed starting fluid, tried to start the motor... and NO SPARK...??

So: Tested OHMS on coil: Very low resistance on positive and negative primary posts on coil. 3.5 ohms I believe. The primary to secondary was 4300 OHMs which I think is very low (shouldn't this be 18000ish?), right? So I have another coil, it tested the same on primary, but to secondary was 6900 ohms. also low I think. Neither coil produces spark.

Also, I get 11.9 vdc to test point on Coil when it's mounted in the ICM. When it cranks, I get 7.9 vdc. Is that ok?

I've done all the renix things... ground refresh, added grounds, followed Cruiser54's info. Found a TSB about rerouting the CPS wires and such. Good battery. Musical Relays.

Can anyone give me insight on where to go from here? What to test? I refuse to throw parts and money at this without being able to test parts unless I absolutely have to do so. Almost to the BURN IT DOWN point.

Thanks!

[djgrayxj]

Note from DJ

Here is some of the information you were asking for regarding the CPS wiring.

According to my notes the CPS terminal A is Violet with White tracer to the ECU 32 pin connector #201 terminal C1 which is the sensor input.

CPS terminal B is White with Black tracer to the ECU 32 pin connector #201terminal D1 which is the ground.

And of course make sure that the wiring from the CPS to the ECU can never come in contact with the hot exhaust system.

[b5blue]

I use a "Mag-Daddy" magnetic wire holder to keep the CPS wire safe, works like a charm. Check your grounds and all battery connections for good contact/condition. Check battery condition as those readings seem low.

[FilthyLlama]

Thanks guys. I had re-wired the CPS to the computer backwards... it still had spark every now and then that way, though. Weird! All straightened out. And I've put all the wires in loom and secured away from heat.

I've actually got this thing started. Everything was testing 'ok', I even had the Local Parts STore test the ICM and they said it was good. New one there was $145, so I was happy it was good. HOWEVER, after all this trouble shooting and wiring and electrical tape removal looking for broken/frayed wires... I found an Ignition Control Module for $55 at Napa. Took a $55 gamble, and I have a running jeep again (for now, ugh!)

So my problem was fixed with an ignition control module.

Symptoms: After replacing CPS I had spark; ran for a minute then just quit like something broke (not like the fuel cut out) then had no spark again.

Solution: New Ingition Control Module

I'll be taking the old ICM back to the store to see if it still tests good. I imagine it has an internal short or something that makes it work sometimes and not others.

Jeep's running. Replacing Power steering pump and lower radiator hose while I'm there tonight. Has terrible leak in exhaust header that I just found now that it's running

Thanks again!

[cruiser54]

Good news.

Ever seen this?

http://www.cherokeetech.com/VBull/sh...796#post103796

[FilthyLlama]

Holy hell, nope! I've seen parts of that all over and have used many of those already to better my Renix. I'll be spending the next hour or so and many an afternoon in the future going through the rest of that list and completing the ones that are pertinent to my 2 door.

Cruiser’s Headlight Upgrade Harness Instructions

I've seen this in a few places... what supplemental harness is it speaking of? Some OEM I can purchase, or just one you make? Every time I read it my mind thinks I've missed something.

Took the Jeep (heretofore named "2Doug") on a trip hunting this weekend. Performed well. I have to take care of some mechanical things (this poor fella was severely neglected). I tested the 4wd before my trip and it was working. In the mountains, however, 4 wheel drive cut out and got me stuck, but it's working again now... strange. Upgrading the suspension and gears soon, so I was planning on rebuilding/upgrading the transfer case anywho.

But yup, didn't get stranded! Thanks for that link, Cruiser!

[cruiser54]

Originally Posted by FilthyLlama

Holy hell, nope! I've seen parts of that all over and have used many of those already to better my Renix. I'll be spending the next hour or so and many an afternoon in the future going through the rest of that list and completing the ones that are pertinent to my 2 door.


I've seen this in a few places... what supplemental harness is it speaking of? Some OEM I can purchase, or just one you make? Every time I read it my mind thinks I've missed something.

Took the Jeep (heretofore named "2Doug") on a trip hunting this weekend. Performed well. I have to take care of some mechanical things (this poor fella was severely neglected). I tested the 4wd before my trip and it was working. In the mountains, however, 4 wheel drive cut out and got me stuck, but it's working again now... strange. Upgrading the suspension and gears soon, so I was planning on rebuilding/upgrading the transfer case anywho.

But yup, didn't get stranded! Thanks for that link, Cruiser!

http://www.ebay.com/itm/CERAMIC-H4-H...item4d05ffa39e

[djgrayxj]

Note from DJ
Here is two example of relay operated headlamp wiring upgrade that I had saved.

It is simple to build your own Headlamp Relay Harness
From JeepForum.com
By Slithering Joe
http://www.jeepforum.com/forum/showthread.php?t=510221

Heavy duty Headlight Loom By Go Jeep-XJ
http://www.go.jeep-xj.info/HowtoHeadlightLoom.htm

[FilthyLlama]

I've got that Jeep-XJ.info link bookmarked from about 6 years ago, maybe longer hah. Thanks!

I'll be fixing the hydraulic hoses to the steering pump tonight. And doing some research on why I didn't have 4 wheel drive while I was sideways on the icy mountain yesterday shortly after the power steering pump fix.

Got license plates today. Plan on putting some redneck implying stickers on the windows before Thanksgiving. Yup. Must be a keeper. Just glad I'm going through all the major components... I think I have a hub up front failing, for instance. I'm sure the transmission could use a fluids change. And diffs (but as I've said, they'll be getting new gears soon, and hopefully a locker, so I'll be changing them anyway).

The TPS adjustment and IAC cleaning from the intensive list you shared might happen tonight as well! My idle is high, so maybe that will help.

Gotta love a project. Letting this thread die now