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No Spark, No go

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Old Dec 19, 2010 | 10:06 PM
  #1  
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Year: 1998
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Engine: 4.0 I6
Default No Spark, No go

I need some help getting my jeep back on the road.

I have a '98 XJ that recently died on me. While i was driving down the road at about 30 I went to shift into 3rd gear and the engine died. I tried to put it into second while still rolling and pop the clutch, but it wouldn't start back up. I pulled off the road and tried to start it up again, but it wouldn't start.

The engine will crank but will not fire. I thought it was the fuel pump, but I tested the pressure at the rail and I do have fuel pressure when the key is in the ON position.

Next I pulled one of the plugs to check for spark and got none. I removed the coil cable and tested that with a simple on/off voltage tester and there was no voltage. I then tested the output of the ignition coil with the same results.

I have checked the CPS plug to make sure there is a good connection there, and there was.

So my question is what could be causing the lack of spark besides a bad CPS???
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Old Dec 19, 2010 | 11:30 PM
  #2  
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From: Eagle Mountain, Utah
Year: 1994
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Originally Posted by uBapimp
I need some help getting my jeep back on the road.

I have a '98 XJ that recently died on me. While i was driving down the road at about 30 I went to shift into 3rd gear and the engine died. I tried to put it into second while still rolling and pop the clutch, but it wouldn't start back up. I pulled off the road and tried to start it up again, but it wouldn't start.

The engine will crank but will not fire. I thought it was the fuel pump, but I tested the pressure at the rail and I do have fuel pressure when the key is in the ON position.

Next I pulled one of the plugs to check for spark and got none. I removed the coil cable and tested that with a simple on/off voltage tester and there was no voltage. I then tested the output of the ignition coil with the same results.

I have checked the CPS plug to make sure there is a good connection there, and there was.

So my question is what could be causing the lack of spark besides a bad CPS???
You checked the CPS connection, but is the CPS good? If it's not giving the proper signal to the computer no sparky sparky. Sounds like it could be a CPS to me...
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Old Dec 19, 2010 | 11:52 PM
  #3  
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Year: 1998
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I'm going to get a digital multimeter tomorrow and check the CPS. I'm hoping it's that easy.
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Old Dec 20, 2010 | 12:33 AM
  #4  
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Year: 1989 xj sport 2dr
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did you make sure the coils getting power to it
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Old Dec 20, 2010 | 01:34 AM
  #5  
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I tried the simple volt meter on the harness plug to the coil and didn't get anything. I will check it again with the multimeter tomorrow.
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Old Dec 20, 2010 | 05:40 AM
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Crank sensor is suspect #1 here.

Without the input from that sensor to the computer, you will NOT have spark and even though you might have fuel pressure at the rail, you will not have fuel going TO the fuel injectors.

Test your crank sensor. Ignition coil and ignition switch are also in play, but the crank sensor is a very common failure, more so than the other things mentioned.
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Old Jan 7, 2011 | 02:31 PM
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Okay, sorry for the long delay... I've had a lot going on over the holidays...

So I've tested the Crank Position Sensor and the resistance of the sensor would read for a brief second and then acts like it's open. When I tried to test the voltage while cranking it didn't read anything which leads me to believe the sensor is indeed bad.

I've purchased a new sensor and am about to install it. I will keep you all posted.
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Old Jan 7, 2011 | 03:49 PM
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Looks like a trip to sears is in order... It is a pain to get to those mounting bolts.
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Old Jan 7, 2011 | 03:57 PM
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Year: 1986 Comanche
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Originally Posted by uBapimp
Looks like a trip to sears is in order... It is a pain to get to those mounting bolts.
There's two ways you can get to them. If you remove the air box, you can reach back with a wrench to get the two bolts out. The other way is if you get long extensions with a swivel socket and fish it in from under the Jeep, from behind the transfer case. If you choose to do it the other way, buy a friend a beer and have him/her reach down and hold the socket on the bolts as you turn them out.

When I did a CPS on my Comanche, I chose to us the wrench since I was the only one here. I have done it both ways when I worked in a local garage.
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Old Jan 7, 2011 | 04:53 PM
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Thanks, I just got some extensions and a U-joint, and I'm going have my roommate give me a hand when he gets off work. Many beers will be in order
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Old Jan 11, 2011 | 04:39 PM
  #11  
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New crank position sensor installed... Still won't start

What could be the next culprit???
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Old Jan 11, 2011 | 05:31 PM
  #12  
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Year: 1998
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Just a quick question. When you turn your key to on does your check engine light go on for a second and then turn off?
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Old Jan 11, 2011 | 05:39 PM
  #13  
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From: sevierville,tn
Year: 1996
Model: Cherokee
Engine: 4.0L
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Oh have u checked your rotor or ur pick up. And have u checked the mini fuse under the hood. There is one that controls spark mine when out and I spent days trying to figure out y it had no spark
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Old Jan 11, 2011 | 05:53 PM
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Year: 1998
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+2 on the pickup. Very possible that is bad.
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Old Jan 11, 2011 | 06:20 PM
  #15  
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The check engine light doesn't come on, and when I checked earlier I wasn't getting power to the distributor or the ignition coil.
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