Help! Renix no start!
Thread Starter
Seasoned Member
Joined: Jul 2012
Posts: 312
Likes: 0
From: Little Elm, TX
Year: 1987
Model: Cherokee
Engine: Inline 6 cylinder
Ok guys, I really desperately need help. My Jeep isn't starting. [{(I'm not getting any spark!}] But, I am getting fuel and air. So, my guess was the CPS, changed it and tested it using this method:
"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."
When I test it this way I'm only getting .2 AC volts. I have done it with 2 new crankshaft position sensors, both from NAPA. Both only read the .2 AC volts, not the .5 AC volts that is needed. So, I'm wondering what could cause this. I'm also trying to think of other reasons that I am not getting spark. Any and all help is appreciated. Thanks in advance.
"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."
When I test it this way I'm only getting .2 AC volts. I have done it with 2 new crankshaft position sensors, both from NAPA. Both only read the .2 AC volts, not the .5 AC volts that is needed. So, I'm wondering what could cause this. I'm also trying to think of other reasons that I am not getting spark. Any and all help is appreciated. Thanks in advance.
Last edited by matt0106; Feb 26, 2015 at 10:32 PM.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Well, if you've still got the C101 connector, that low AC voltage may be dropping through it and the ECU is seeing even less.
Try drilling the upper mounting hole in the CPS?
Eliminate the C101? Tip 27.
Just bypass the C101 CPS wires?
Try drilling the upper mounting hole in the CPS?
Eliminate the C101? Tip 27.
Just bypass the C101 CPS wires?
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Member
Joined: May 2014
Posts: 115
Likes: 0
From: Albuquerque, NM
Year: 1987
Model: Cherokee
Engine: 4.0L
What kit are you talking about? You can just bypass the C101 like cruiser said. You really should just delete the C101 if you have the time. If you take it apart, you will see just how dirty and disgusting it is, mine wasn't even worth cleaning.
Thread Starter
Seasoned Member
Joined: Jul 2012
Posts: 312
Likes: 0
From: Little Elm, TX
Year: 1987
Model: Cherokee
Engine: Inline 6 cylinder
This is what I'm talking about:
"http://www.lunghd.com/Downloads_and_Links/CPS-87-90-update.pdf"
Even if I connect it directly to the ECU or eliminate the C101, the signal from the CPS would still be only .2 AC volts.
"http://www.lunghd.com/Downloads_and_Links/CPS-87-90-update.pdf"
Even if I connect it directly to the ECU or eliminate the C101, the signal from the CPS would still be only .2 AC volts.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
If it were mine, I would eliminate the C101 and drill the mounting tab on the CPS.
Thread Starter
Seasoned Member
Joined: Jul 2012
Posts: 312
Likes: 0
From: Little Elm, TX
Year: 1987
Model: Cherokee
Engine: Inline 6 cylinder
If I drill out the holes, should I do both or what? And could I just eliminate the connector for just the CPS. My main concern is getting my jeep running. I can worry about the other parts of the connector later.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Just do the CPS wires for now. I have numerous times.
CF Veteran

Joined: Oct 2010
Posts: 2,150
Likes: 12
From: Ontario, Canada
Year: 1989 Laredo
Model: Cherokee
Engine: 4.0 L 6 Renix
Drill one hole only per the instruction.
Drilling both could lead into too much repositioning and crash the sensor tip into the flywheel.
Drilling both could lead into too much repositioning and crash the sensor tip into the flywheel.


