Another won't start thread
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Member
Joined: Jan 2010
Posts: 208
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From: Moses Lake Wa
Year: 1989
Model: Cherokee
Another won't start thread
Hey guys, been a while since I've been on. Anyways, today I replaced radiator, water pump and belt. Now it will crank but won't start. I'm aware of CPS issues and will test it tomorrow. I've already replaced 3 of them, then discovered there was a broken wire in the harness. My rig has been sitting all winter, starting it about once a month. But today it didn't want to cooperate. Any help would be appreciated.
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Thread Starter
Member
Joined: Jan 2010
Posts: 208
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From: Moses Lake Wa
Year: 1989
Model: Cherokee
Thread Starter
Member
Joined: Jan 2010
Posts: 208
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From: Moses Lake Wa
Year: 1989
Model: Cherokee
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Year: 2000 and 1998
Model: Cherokee
Engine: 4.0
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From: Fort Erie, CANADA
Year: 1987
Model: Cherokee
Engine: 4.0
In my experience, my Cherokee is fussy about batteries being fully charged and cranking at the right speed. I think the CPS just provides the ECU the position the crankshaft so it can know where the pistons are and then fire the injectors at the appropriate time. I don't know if the engine has to turn over at a certain rate (RPM) before it will start.
I've found that a weak battery that doesn't turn the engine over quickly enough just won't get the Jeep started at all. Not sure if the CPS output voltage is proportional to the number of teeth spinning past it. If it's cranking slow, maybe it won't generate the right voltage?? Maybe Cruiser knows about this detail but regardless, I like to rule out the simple stuff like fuel filter, battery, spark plugs etc before I get into the details.
I've found that a weak battery that doesn't turn the engine over quickly enough just won't get the Jeep started at all. Not sure if the CPS output voltage is proportional to the number of teeth spinning past it. If it's cranking slow, maybe it won't generate the right voltage?? Maybe Cruiser knows about this detail but regardless, I like to rule out the simple stuff like fuel filter, battery, spark plugs etc before I get into the details.
Thread Starter
Member
Joined: Jan 2010
Posts: 208
Likes: 0
From: Moses Lake Wa
Year: 1989
Model: Cherokee
In my experience, my Cherokee is fussy about batteries being fully charged and cranking at the right speed. I think the CPS just provides the ECU the position the crankshaft so it can know where the pistons are and then fire the injectors at the appropriate time. I don't know if the engine has to turn over at a certain rate (RPM) before it will start.
I've found that a weak battery that doesn't turn the engine over quickly enough just won't get the Jeep started at all. Not sure if the CPS output voltage is proportional to the number of teeth spinning past it. If it's cranking slow, maybe it won't generate the right voltage?? Maybe Cruiser knows about this detail but regardless, I like to rule out the simple stuff like fuel filter, battery, spark plugs etc before I get into the details.
I've found that a weak battery that doesn't turn the engine over quickly enough just won't get the Jeep started at all. Not sure if the CPS output voltage is proportional to the number of teeth spinning past it. If it's cranking slow, maybe it won't generate the right voltage?? Maybe Cruiser knows about this detail but regardless, I like to rule out the simple stuff like fuel filter, battery, spark plugs etc before I get into the details.