95 Wrangler ignition problems - JeepForum.com
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post #1 of 6 Old 04-24-2013, 07:16 AM Thread Starter
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95 Wrangler ignition problems

My vehicle is a 1995 Jeep Wrangler Sahara V6 4.0L Automatic.
I'm getting error codes

11 - No crank reference signal detected during engine cranking. Intermittent loss of either camshaft or crankshaft position sensor. CKP sensor target windows have too much variation.

12 - Direct battery input to PCM was disconnected within the last 50 Key-on cycles.

17 - Engine did not reach operating temperature within acceptable limits. Engine does not reach 20 F. within 5 minutes with a vehicle speed signal.

Explanation for 17, I was told there is no thermostat on my jeep.

I have fuel coming through the injectors, the pressure is good. The spark is pretty weak. Sometimes it fires, sometimes it doesn't. I replaced the Crankshaft position sensor, and Camshaft position sensor, the coil. Nothing happened. All the relays are working and relative fuses are in tact and the wires connected to the crankshaft and camshaft sensors both have power. This has been going on for a few days and I can't figure out why. Advice would be appreciated

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post #2 of 6 Old 04-24-2013, 09:43 AM
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1991 YJ Wrangler 
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Sounds like you checked/performed the obvious stuff. I don't really understand code 17 if she isn't running though. You may have a wiring issue. One common issue that you should rule out is to check the wiring to the O2 sensor. Most of your sensors share common power. The O2 wiring, given it's location... it is somewhat common to have the wiring melt against the exhaust down pipe and or become entangled on the front drive shaft. If this wiring shorted out, it can cause the issues you are seeing. Beyond that, I would disconnect the battery and then the ECM connector and ohm out the CPS sensor wiring back to the ECM connector. Removing the windshield washer bottle/reservoir aids greatly in doing this. From the CPS connector, the gry/blk wire should ohm to pin 24 of the ECM connector, CPS connector blk/lt blu wire should ohm to ECM pin 4, CPS connector org wire should ohm to ECM pin 7. Also check all to chassis ground to see if any are shorted. Reconnect ECM, CPS, then lastly battery and recheck codes and report back.
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post #3 of 6 Old 04-24-2013, 11:55 AM Thread Starter
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Thanks for the info, I did everything you said.

Checked the O2 wires, there were no shorts nor tangles anywhere. When we opened up the ECM connector we found a little bit of water build up. That's all cleaned. All the pins went great with the wires you said. No problems there. The person reading the meter ( I don't know how) Said he noticed no problems. Checking all the wires to ground, they remarked that the Black/Light Blue wire had a resistance of 15.4 when measured to ground. He was wondering what that might mean for that wire. Everything's re-connected now and the codes have updated! Now I'm getting 12, 55. Which is the "Direct battery input to PCM was disconnected within the last 50 Key-on cycles." Which has nothing to do with anything. So the codes are gone, but still no engine start up! Hope to hear back from you soon and thanks again for the advice. In the mean time, I'll do more research and keep this updated until I hear back with more helpful advice.
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post #4 of 6 Old 04-25-2013, 08:47 AM Thread Starter
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No explanation for the codes 11 & 17 going away. Still having the same problems as before. Intermittent spark. Could this be a problem with my ECM? If so, how can I test it? Additionally, when I look at my distributor cap and the placement of the spark cables, The screws on the cap never line up to the picture I'm looking at. Can anyone provide me some information about the order of plugs on my cap? Or explain why my screws seem to be turned 180 degrees?
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post #5 of 6 Old 04-26-2013, 10:56 AM
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1989 YJ Wrangler 
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Your firing order is clockwise 1,5,3,4,6,2. The big 3 on spark is cam, crank, and coil. You have replaced all 3 so yes it could be the ecu. Did you check all your grounds and the cap and rotor. When you replaced the cam/pickup sensor did you replace the entire distributor?
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post #6 of 6 Old 05-01-2013, 07:14 PM Thread Starter
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My firing order is fine in that case. I just received a refurbished ECU and I am still not getting any ignition. We are at a loss with what to do, going crazy.
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