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Unread 07-20-2013, 12:28 AM   #31
bigb229
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1998 ZJ 
 
Join Date: Feb 2010
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All cap wires and plugs are brand new and the oem coil produced the same results....getting a solid 5v signal

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Unread 07-20-2013, 08:10 AM   #32
ZeeJay1997
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Quote:
Originally Posted by bigb229 View Post
We're getting like .4 ohms resistance through the grounds and 5 volts on the supply.
If you were measuring voltage across the connector for the injector, this may be somewhere in the ball park. If the reference you were using is a pulsed signal from the PCM, it would make the supply voltage look lower on a meter.

When measuring injector voltage, your black lead should go to to battery ground and the red lead to the green/ black or whatever color wire is common to all injectors. You should read 12v while running.

Did you measure the resistance of the injectors themselves?
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Unread 07-22-2013, 09:29 AM   #33
bigb229
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Alright guys dealership called and said that when they unplug the ckps the computer can talk to the jeep. Plug it in and it won't talk to the jeep......
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Unread 07-22-2013, 09:56 AM   #34
Rich93ZJ
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Sounds like the crank sensor is shorted. Kinda make sense since the cam and crank sensors work together to control the timing. Did you ever get a o-scope on the signal wires and see where the signals were at? I bet the crank signal is all over the place.
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Unread 07-22-2013, 09:57 AM   #35
bigb229
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It's a brand new sensor and was doing the same thing with the previous sensor. Sounds like the short is in that system or wires though.
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Unread 07-22-2013, 11:28 AM   #36
dellis
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Quote:
Originally Posted by bigb229 View Post
Alright guys dealership called and said that when they unplug the ckps the computer can talk to the jeep. Plug it in and it won't talk to the jeep......
Did you notice the same thing when you attached a ODBII scanner to the Jeep? Have you put a meter on the 5V supply to see its value?

If it is a short on the 5V supply (or more likely, a resistive short where the voltage is under 5V), the short could be on the camshaft position sensor (CMPS), TPS the MAP, or the CKPS. Unplugging one at a time and remeasuring the voltage might isolate the problem.
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Unread 07-22-2013, 05:32 PM   #37
bigb229
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We just have a code reader and the jeep was not throwing codes. Dealership says that the crank sensors I was using, napa brand, were shorted and shorting out the data bus. They're going to start with a mopar sensor in the morning and then trace it back into the bus. I'm fairly certain my sensor is fine and there is a wiring issue further down the line. Maybe I'm wrong.
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Unread 07-22-2013, 05:39 PM   #38
Rich93ZJ
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This is common with non Mopar sensors. Valuable lesson learned. MOPAR ONLY!!!!
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Unread 07-22-2013, 05:59 PM   #39
bigb229
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Originally Posted by Rich93ZJ View Post
This is common with non Mopar sensors. Valuable lesson learned. MOPAR ONLY!!!!
TBH I've run several different types of sensors and napa has always worked just fine. They have t confirmed that the mopar sensor is the fix so well keep valuable lessons learned off the table for now.
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Unread 07-22-2013, 08:24 PM   #40
Oldfrog
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It's pretty common knowledge here that you use only a Mopar crank sensor. Some have gotten by with aftermarket models....but generally, Jeeps crave Mopar sensors...especially the crank sensor.

'May or not be your issue in this case...but there's no sense in even buying anything else because you may have to chunk it in the trash and still get the Mopar crank sensor.
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