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ignition control module/coil problems please help

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yesterday my truck died on the road. I trailered it home and found i was getting no spark from the coil. i have a parts cherokee so i pulled the ignition controll module and coil off of it (since they come off in one piece) and put them on mine. it started right up. i took off for school this morning and only made it about a mile before it did the exact same thing. what could be causing my truck to do this? thanks for any help.

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Could be the connector or the crank sensor is going out. Possibly worn out ignition switch. See if it restarts after sitting a bit.


it does restart after it gets cool apparently. it only dies after ive driven it about a mile and then cuts off and won't get spark. how do i check the connector or crank sensor?

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Here ya go. It's still in a rough draft form but it should work for you.


Renix CPS Testing and Adjusting




Renix TPSs 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.


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 3.5 range 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.

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