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89 xj no spark

kevinO

NAXJA Forum User
Location
riverside ca
my 89 xj will not start i get no spark from the coil check/changed the coil and the ecm. no difference. last time it was the ballast on the firewall but changed that out too. running out of spare / good parts to throw at it. any ideas?
 
my 89 xj will not start i get no spark from the coil check/changed the coil and the ecm. no difference. last time it was the ballast on the firewall but changed that out too. running out of spare / good parts to throw at it. any ideas?

I have had both the coil and the ignition control module go bad at different times. I changed the coil the first time...fixed the problem....then later the ignition control module went out took it to Oreillys, had it checked and it was the culprit that time.

Are you getting power to the ignition control module?
 
CPS? Did you test it? This is on the bell housing on the top side of the driverside.I removed mine and found it full of oil and crap , cleaned it real good and reinstalled it and she fired up.

HTH
 
Do this before wasting any more time and money:

Renix CPS Testing and Adjusting
 
 
Renix CPSs have to put out a strong enough signal to the ECU so that it will provide spark.
Most tests for the CPS suggest checking it for an ohms value. This is unreliable and can cause some wasted time and aggravation in your diagnosis of a no-start issue as the CPS will test good when in fact it is bad.
The problem with the ohms test is you can have the correct amount of resistance through the CPS but it isn’t generating enough voltage to trigger the ECU to provide spark.
Unplug the harness connector from the CPS. Using your voltmeter set on AC volts and probing both wires in the connector going to the CPS, crank the engine over. It won’t start with the CPS disconnected.
You should get a reading of .5 AC volts.
If you are down in the .35 AC volts range or lower on your meter reading, you can have intermittent crank/no-start conditions from your Renix Jeep. Some NEW CPSs (from the big box parts stores) have registered only .2 AC volts while reading the proper resistance!! That’s a definite no-start condition. Best to buy your CPS from Napa or the dealer.
Sometimes on a manual transmission equipped Renix Jeep there is an accumulation of debris on the tip of the CPS. It’s worn off clutch material and since the CPS is a magnet, the metal sticks to the tip of the CPS causing a reduced voltage signal. You MAY get by with cleaning the tip of the CPS off.
A little trick for increasing the output of your CPS is to drill out it’s mounting holes with the first drill bit that just won’t fit through the original holes. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts.
 
Revised 11-29-2011
 
hey thanks for all the help guyz. it was the CPS and the wires had the insulation melted off which is kinda making me wonder why.looked like OEM part still so after 24 years of service i guess solvents and heat could've done that to it.lemme know if you think there is something else that would have caused it..
 
wow it was a more work to get it in the 2 brackets than to mount it! need hands the size of a lil' kid to put it in the brackets
 
There is usually enough extra wire on the CPS so you can cable tie the excess to the speedo cable without trying to roll it up or worry about the extra wire flopping onto the rear of the exhaust manifold.
 
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