Need help in troubleshooting ignition problem
 

My 95 Grand Cherokee would not start today. It is not getting any ignition.
The engine turns over fine but there is no spark from spark plug wires or
from the coil. I've tested the coil with a ohmmeter and it checked out fine.
I replaced the distributor cap and rotor button, but that didn't help. I
fear it might be the Powertrain Control Module(PCM). My Haynes repair manual
does not explain how to test this. Does anyone here know? Is there something
else I should check? I have a 4.0L V6 motor.

Any suggestions would be greatly appreciated.

BTW- If it is the Powertrain Control Module, is it possible to purchase an
after-market PCM that is better? I saw this on Ebay:
http://cgi.ebay.com/ebaymotors/ws/eB...category=33597
but I don't know if it a PCM replacement or just an add on.


Steve Smith

Re: Need help in troubleshooting ignition problem
 

Hi Steve,
Ninety nine and nine tens percent of the time it is the Crankshaft
Position Sensor:
http://www.off-road.com/jeep/cheroke...tdcsensor.html
Pictured:
http://members.cox.net/wilsond/Fixes...tml#CPSdetails
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Steve Smith wrote:
>
> My 95 Grand Cherokee would not start today. It is not getting any ignition.
> The engine turns over fine but there is no spark from spark plug wires or
> from the coil. I've tested the coil with a ohmmeter and it checked out fine.
> I replaced the distributor cap and rotor button, but that didn't help. I
> fear it might be the Powertrain Control Module(PCM). My Haynes repair manual
> does not explain how to test this. Does anyone here know? Is there something
> else I should check? I have a 4.0L V6 motor.
>
> Any suggestions would be greatly appreciated.
>
> BTW- If it is the Powertrain Control Module, is it possible to purchase an
> after-market PCM that is better? I saw this on Ebay:
> http://cgi.ebay.com/ebaymotors/ws/eB...category=33597
> but I don't know if it a PCM replacement or just an add on.
>
> Steve Smith

Re: Need help in troubleshooting ignition problem
 

Hi Steve,
Ninety nine and nine tens percent of the time it is the Crankshaft
Position Sensor:
http://www.off-road.com/jeep/cheroke...tdcsensor.html
Pictured:
http://members.cox.net/wilsond/Fixes...tml#CPSdetails
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Steve Smith wrote:
>
> My 95 Grand Cherokee would not start today. It is not getting any ignition.
> The engine turns over fine but there is no spark from spark plug wires or
> from the coil. I've tested the coil with a ohmmeter and it checked out fine.
> I replaced the distributor cap and rotor button, but that didn't help. I
> fear it might be the Powertrain Control Module(PCM). My Haynes repair manual
> does not explain how to test this. Does anyone here know? Is there something
> else I should check? I have a 4.0L V6 motor.
>
> Any suggestions would be greatly appreciated.
>
> BTW- If it is the Powertrain Control Module, is it possible to purchase an
> after-market PCM that is better? I saw this on Ebay:
> http://cgi.ebay.com/ebaymotors/ws/eB...category=33597
> but I don't know if it a PCM replacement or just an add on.
>
> Steve Smith

Re: Need help in troubleshooting ignition problem
 

Hi Steve,
Ninety nine and nine tens percent of the time it is the Crankshaft
Position Sensor:
http://www.off-road.com/jeep/cheroke...tdcsensor.html
Pictured:
http://members.cox.net/wilsond/Fixes...tml#CPSdetails
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Steve Smith wrote:
>
> My 95 Grand Cherokee would not start today. It is not getting any ignition.
> The engine turns over fine but there is no spark from spark plug wires or
> from the coil. I've tested the coil with a ohmmeter and it checked out fine.
> I replaced the distributor cap and rotor button, but that didn't help. I
> fear it might be the Powertrain Control Module(PCM). My Haynes repair manual
> does not explain how to test this. Does anyone here know? Is there something
> else I should check? I have a 4.0L V6 motor.
>
> Any suggestions would be greatly appreciated.
>
> BTW- If it is the Powertrain Control Module, is it possible to purchase an
> after-market PCM that is better? I saw this on Ebay:
> http://cgi.ebay.com/ebaymotors/ws/eB...category=33597
> but I don't know if it a PCM replacement or just an add on.
>
> Steve Smith

Re: Need help in troubleshooting ignition problem
 

On Sat, 2 Apr 2005 22:29:00 -0500, "Steve Smith"
<s.w.smithREMOVECAPS@ctliving.net> wrote:

>My 95 Grand Cherokee would not start today. It is not getting any ignition.
>The engine turns over fine but there is no spark from spark plug wires or
>from the coil. I've tested the coil with a ohmmeter and it checked out fine.
>I replaced the distributor cap and rotor button, but that didn't help. I
>fear it might be the Powertrain Control Module(PCM). My Haynes repair manual
>does not explain how to test this. Does anyone here know? Is there something
>else I should check? I have a 4.0L V6 motor.
>
>Any suggestions would be greatly appreciated.
>
>BTW- If it is the Powertrain Control Module, is it possible to purchase an
>after-market PCM that is better? I saw this on Ebay:
>http://cgi.ebay.com/ebaymotors/ws/eB...category=33597
>but I don't know if it a PCM replacement or just an add on.
>
>
>Steve Smith

First check the Crankcase Position Sensor. Many a jeep owner has
cursed the *%$**!! who designed that stupid thing!

Next up I would replace the coil anyway. I've seen a perfectly good
reading come from a coil that still won't spark. Rare, but I have
seen it.

Can't think of anything else...but then again it's 4:00am (just
finished putting in a new stereo in the XJ).


Drifter
"I've been here, I've been there..."

Re: Need help in troubleshooting ignition problem
 

On Sat, 2 Apr 2005 22:29:00 -0500, "Steve Smith"
<s.w.smithREMOVECAPS@ctliving.net> wrote:

>My 95 Grand Cherokee would not start today. It is not getting any ignition.
>The engine turns over fine but there is no spark from spark plug wires or
>from the coil. I've tested the coil with a ohmmeter and it checked out fine.
>I replaced the distributor cap and rotor button, but that didn't help. I
>fear it might be the Powertrain Control Module(PCM). My Haynes repair manual
>does not explain how to test this. Does anyone here know? Is there something
>else I should check? I have a 4.0L V6 motor.
>
>Any suggestions would be greatly appreciated.
>
>BTW- If it is the Powertrain Control Module, is it possible to purchase an
>after-market PCM that is better? I saw this on Ebay:
>http://cgi.ebay.com/ebaymotors/ws/eB...category=33597
>but I don't know if it a PCM replacement or just an add on.
>
>
>Steve Smith

First check the Crankcase Position Sensor. Many a jeep owner has
cursed the *%$**!! who designed that stupid thing!

Next up I would replace the coil anyway. I've seen a perfectly good
reading come from a coil that still won't spark. Rare, but I have
seen it.

Can't think of anything else...but then again it's 4:00am (just
finished putting in a new stereo in the XJ).


Drifter
"I've been here, I've been there..."

Re: Need help in troubleshooting ignition problem
 

On Sat, 2 Apr 2005 22:29:00 -0500, "Steve Smith"
<s.w.smithREMOVECAPS@ctliving.net> wrote:

>My 95 Grand Cherokee would not start today. It is not getting any ignition.
>The engine turns over fine but there is no spark from spark plug wires or
>from the coil. I've tested the coil with a ohmmeter and it checked out fine.
>I replaced the distributor cap and rotor button, but that didn't help. I
>fear it might be the Powertrain Control Module(PCM). My Haynes repair manual
>does not explain how to test this. Does anyone here know? Is there something
>else I should check? I have a 4.0L V6 motor.
>
>Any suggestions would be greatly appreciated.
>
>BTW- If it is the Powertrain Control Module, is it possible to purchase an
>after-market PCM that is better? I saw this on Ebay:
>http://cgi.ebay.com/ebaymotors/ws/eB...category=33597
>but I don't know if it a PCM replacement or just an add on.
>
>
>Steve Smith

First check the Crankcase Position Sensor. Many a jeep owner has
cursed the *%$**!! who designed that stupid thing!

Next up I would replace the coil anyway. I've seen a perfectly good
reading come from a coil that still won't spark. Rare, but I have
seen it.

Can't think of anything else...but then again it's 4:00am (just
finished putting in a new stereo in the XJ).


Drifter
"I've been here, I've been there..."

Re: Need help in troubleshooting ignition problem
 

Bill, do V6's have that CPS? He says he has the V6.

But other than a dead CPS, how is the body ground? If bad no spark. I
test them by running a booster cable from the battery negative to the
firewall. On the straight six, the ground is a wire mesh strap from the
head to the firewall, don't know where it is on the V6 or V8.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

"L.W.(ßill) ------ III" wrote:
>
> Hi Steve,
> Ninety nine and nine tens percent of the time it is the Crankshaft
> Position Sensor:
> http://www.off-road.com/jeep/cheroke...tdcsensor.html
> Pictured:
> http://members.cox.net/wilsond/Fixes...tml#CPSdetails
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> Steve Smith wrote:
> >
> > My 95 Grand Cherokee would not start today. It is not getting any ignition.
> > The engine turns over fine but there is no spark from spark plug wires or
> > from the coil. I've tested the coil with a ohmmeter and it checked out fine.
> > I replaced the distributor cap and rotor button, but that didn't help. I
> > fear it might be the Powertrain Control Module(PCM). My Haynes repair manual
> > does not explain how to test this. Does anyone here know? Is there something
> > else I should check? I have a 4.0L V6 motor.
> >
> > Any suggestions would be greatly appreciated.
> >
> > BTW- If it is the Powertrain Control Module, is it possible to purchase an
> > after-market PCM that is better? I saw this on Ebay:
> > http://cgi.ebay.com/ebaymotors/ws/eB...category=33597
> > but I don't know if it a PCM replacement or just an add on.
> >
> > Steve Smith

Re: Need help in troubleshooting ignition problem
 

Bill, do V6's have that CPS? He says he has the V6.

But other than a dead CPS, how is the body ground? If bad no spark. I
test them by running a booster cable from the battery negative to the
firewall. On the straight six, the ground is a wire mesh strap from the
head to the firewall, don't know where it is on the V6 or V8.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

"L.W.(ßill) ------ III" wrote:
>
> Hi Steve,
> Ninety nine and nine tens percent of the time it is the Crankshaft
> Position Sensor:
> http://www.off-road.com/jeep/cheroke...tdcsensor.html
> Pictured:
> http://members.cox.net/wilsond/Fixes...tml#CPSdetails
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> Steve Smith wrote:
> >
> > My 95 Grand Cherokee would not start today. It is not getting any ignition.
> > The engine turns over fine but there is no spark from spark plug wires or
> > from the coil. I've tested the coil with a ohmmeter and it checked out fine.
> > I replaced the distributor cap and rotor button, but that didn't help. I
> > fear it might be the Powertrain Control Module(PCM). My Haynes repair manual
> > does not explain how to test this. Does anyone here know? Is there something
> > else I should check? I have a 4.0L V6 motor.
> >
> > Any suggestions would be greatly appreciated.
> >
> > BTW- If it is the Powertrain Control Module, is it possible to purchase an
> > after-market PCM that is better? I saw this on Ebay:
> > http://cgi.ebay.com/ebaymotors/ws/eB...category=33597
> > but I don't know if it a PCM replacement or just an add on.
> >
> > Steve Smith

Re: Need help in troubleshooting ignition problem
 

Bill, do V6's have that CPS? He says he has the V6.

But other than a dead CPS, how is the body ground? If bad no spark. I
test them by running a booster cable from the battery negative to the
firewall. On the straight six, the ground is a wire mesh strap from the
head to the firewall, don't know where it is on the V6 or V8.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

"L.W.(ßill) ------ III" wrote:
>
> Hi Steve,
> Ninety nine and nine tens percent of the time it is the Crankshaft
> Position Sensor:
> http://www.off-road.com/jeep/cheroke...tdcsensor.html
> Pictured:
> http://members.cox.net/wilsond/Fixes...tml#CPSdetails
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> Steve Smith wrote:
> >
> > My 95 Grand Cherokee would not start today. It is not getting any ignition.
> > The engine turns over fine but there is no spark from spark plug wires or
> > from the coil. I've tested the coil with a ohmmeter and it checked out fine.
> > I replaced the distributor cap and rotor button, but that didn't help. I
> > fear it might be the Powertrain Control Module(PCM). My Haynes repair manual
> > does not explain how to test this. Does anyone here know? Is there something
> > else I should check? I have a 4.0L V6 motor.
> >
> > Any suggestions would be greatly appreciated.
> >
> > BTW- If it is the Powertrain Control Module, is it possible to purchase an
> > after-market PCM that is better? I saw this on Ebay:
> > http://cgi.ebay.com/ebaymotors/ws/eB...category=33597
> > but I don't know if it a PCM replacement or just an add on.
> >
> > Steve Smith