In need of Renix Gu-ru!!!

[quikguy240]

87' XJ not recieving spark from coil. New cps, new dist., new coil and module. Still no spark. I am recieving power to the coil from one wire. There are two plugs that go into the module, one with 3 wires and the other with one wire. The 3 wire plug has a yellow which is hot, a black which is ground, and a green/black that runs to a sensor I can't remember. The yellow wire on that plug has power with ign. in the on pos. The other plug also has a yellow wire. I don't know where that wire goes nor if it's supposed to have power. In my past experiances, a wire sharing the same color usually shares a common action thus suggesting to me that the wire should have power running to it. I am not sure, just taking a wild stab in the dark. My next step is the ECU! None of my local dealerships have any books that show the renix system and none can remember that far back. I read in my chilton that you can test the system, but again no one seems to have the special adapter plug.... Also been told that even if I were to come across the correct adapter it would tell me I'm S.O.L.! Therefore I am moving on to the ECU. If that doesn't fix my problem, I fear I will be tapping into the harness itself. PLEASE! I am asking for a RENIX GU-RU!!! Thank you very much!!

AJ

[LEVE]

Download the RENIX manual

HERE

[XJBOB498]

I was a service mgr at a jeep dealership for many years. The most common problem with the system is not getting signal from the crank position sensor.
And the wiring harness from the sensor,mounted on the bell housing, to the ECU under the dash was the most common problem there. Eliminate all connectors in the harness, and you will probably solve your problem. I saw very few ECU or coil module failures, but saw lot's of crank positions sensor problems.

Good Luck

PS I will be coming into a 1987 Cherokee for parts very soon, has a blown engine but was running when the rod exited the block.....
I may be able to help with some used parts.

Bob

[mopar4ever]

To check the crank sensor: locate connector behind engine near #6 exhaust port. Red and white wires(?). Check voltage from sensor. DVOM set to AC voltage. Should be around .3v AC while cranking engine over. It will start with as little as .2 but maybe not every time. Be sure the sensor lead is secured AWAY from the header. That is/was one of most common no start problems.

[quikguy240]

Like I said, I replace the crank positioning sensor, lots of fun might I add!! It appeared that the wires coming from the sensor plugged in to the harness right by the firewall. I didn't see where the wires actually connected with the ECU. That would sure be nice if it was just a bad connection. Thanks for the responses!

[mopar4ever]

Oops! Reread your post. I read the cps as cap. Need new glasses. I made an interesting discovery a few weeks ago. If you have seen or have one of those fancy test lights with a pos and neg lead and led's it will take some of the mystery out of your diagnosis. If I remember correctly there is a single spot(terminal) on the module near the center. That is the tach feed. If the current is switching from the module the lights on the test light will alternate red and green(+-). That would be a bad coil. If one of the three wires in the other input switches it would be the module. I know they are new but new doesn't mean good. Also check the CPS voltage. A new one could be weak or not working also.

[quikguy240]

When you say eliminate the connections from the crank pos. sensor, are you talking about where the sensor plugs into the harness by the firewall?