I've been rebuilding this with my son for a couple of years. He will be 16 in January. We took it out playing in the snow last week. We backed it in the yard and shut it off. The next time we tried to start it, it will crank but no start. We have fuel to the rails and No spark on the coil. I'm at a loss. Please help January is coming fast.

No spark.. try the CPS.
before pulling it for a new one clean the connector and pickup on it(may only be dirty)
Avoid the AUTOZONE replacement have seen many times here that they like to fail. NAPA is where most of us go or the dealer.

Here's how to TEST the CPS.

Click on the link in my signature and do the procedures outlined in posts 1,2, 3 and 4 while you're at it.

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 the upper mounting hole to 3/8” from the stock 5/16”, or slot it so the CPS bracket rests on the bell housing when pushed down. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts.




Revised 01-26-2013

My son also bought a radio and it is installed. Apparently he ran the battery down so its on the charger and I will investigate more this afternoon.
Another question.
This jeep had been sitting in a garage since 2000. When we finally got it started, the injector closest to the firewall leaked and started a small fire. It was put out rather quick but it did damage some wires. Since it is his first vehicle and I want a piece of mind, what are the recommendations for a new wiring harness.

Depending on how much damage was done, you may want to just repair what you have. Solder and heat shrink are a very good way to go. You could visit a salvage yard for some correctly colored donor wire(s). Replacement wiring harnesses are very expensive in my opinion.

I agree they are high. But the Jeep was a Christmas present so very little cost in it so far. I've heard good things about Painless wiring but nothing from a Jeep owner.

I would go pull a donor harness out of another 87-89 if you can locate one not hacked up. Painless wiring is a good product but if I remember "you have to cut to length and wire in the ends?
To address the injector issue, RENIX inj. will eventually leak and start fires, replace the OE ones with new replacements or the way better 703s' or the "volvo?" ones don't know the # on those.