98 TJ power loss & rough idle soon after startup
 

I'm having a problem with my '98 Wrangler, I6, manual transmission:

Within 2 or 3 minutes of starting up, it develops a significant power
loss at speed, and at rest it idles very roughly at approx. 200 or 300
RPM. If I attempt to rev it up while this is happening, it hesitates
and backfires. If I just let it sit idling, it will sort itself out
after a couple of minutes (though occasionally it is bad enough that
it stalls). Alternatively, if I turn the engine off then restart it,
the problem goes away immediately (occasionally, it comes back, but
not as bad and a second restart cures it). This happens regardless of
the weather/temperature or the engine temperature, though it's often
not as bad if the engine is already warm.

I recently gave it a service (oil, oil filter, plugs, and air filter
changed) - this had no effect on the problem.

Has anyone seen and solved a problem like this before? Any
suggestions?

Thanks!

Re: 98 TJ power loss & rough idle soon after startup
 

Your computer is in the limp mode. Try to find out what the fault
code is by: http://minimopar.knizefamily.net/fault/ (Here's hoping
you're not in that the about six month period that won't work for.)
Ninety percent of the time it will be the Crankcase Position Sensor.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

PaulT wrote:
>
> I'm having a problem with my '98 Wrangler, I6, manual transmission:
>
> Within 2 or 3 minutes of starting up, it develops a significant power
> loss at speed, and at rest it idles very roughly at approx. 200 or 300
> RPM. If I attempt to rev it up while this is happening, it hesitates
> and backfires. If I just let it sit idling, it will sort itself out
> after a couple of minutes (though occasionally it is bad enough that
> it stalls). Alternatively, if I turn the engine off then restart it,
> the problem goes away immediately (occasionally, it comes back, but
> not as bad and a second restart cures it). This happens regardless of
> the weather/temperature or the engine temperature, though it's often
> not as bad if the engine is already warm.
>
> I recently gave it a service (oil, oil filter, plugs, and air filter
> changed) - this had no effect on the problem.
>
> Has anyone seen and solved a problem like this before? Any
> suggestions?
>
> Thanks!

Re: 98 TJ power loss & rough idle soon after startup
 

Your computer is in the limp mode. Try to find out what the fault
code is by: http://minimopar.knizefamily.net/fault/ (Here's hoping
you're not in that the about six month period that won't work for.)
Ninety percent of the time it will be the Crankcase Position Sensor.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

PaulT wrote:
>
> I'm having a problem with my '98 Wrangler, I6, manual transmission:
>
> Within 2 or 3 minutes of starting up, it develops a significant power
> loss at speed, and at rest it idles very roughly at approx. 200 or 300
> RPM. If I attempt to rev it up while this is happening, it hesitates
> and backfires. If I just let it sit idling, it will sort itself out
> after a couple of minutes (though occasionally it is bad enough that
> it stalls). Alternatively, if I turn the engine off then restart it,
> the problem goes away immediately (occasionally, it comes back, but
> not as bad and a second restart cures it). This happens regardless of
> the weather/temperature or the engine temperature, though it's often
> not as bad if the engine is already warm.
>
> I recently gave it a service (oil, oil filter, plugs, and air filter
> changed) - this had no effect on the problem.
>
> Has anyone seen and solved a problem like this before? Any
> suggestions?
>
> Thanks!

Re: 98 TJ power loss & rough idle soon after startup
 

Your computer is in the limp mode. Try to find out what the fault
code is by: http://minimopar.knizefamily.net/fault/ (Here's hoping
you're not in that the about six month period that won't work for.)
Ninety percent of the time it will be the Crankcase Position Sensor.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

PaulT wrote:
>
> I'm having a problem with my '98 Wrangler, I6, manual transmission:
>
> Within 2 or 3 minutes of starting up, it develops a significant power
> loss at speed, and at rest it idles very roughly at approx. 200 or 300
> RPM. If I attempt to rev it up while this is happening, it hesitates
> and backfires. If I just let it sit idling, it will sort itself out
> after a couple of minutes (though occasionally it is bad enough that
> it stalls). Alternatively, if I turn the engine off then restart it,
> the problem goes away immediately (occasionally, it comes back, but
> not as bad and a second restart cures it). This happens regardless of
> the weather/temperature or the engine temperature, though it's often
> not as bad if the engine is already warm.
>
> I recently gave it a service (oil, oil filter, plugs, and air filter
> changed) - this had no effect on the problem.
>
> Has anyone seen and solved a problem like this before? Any
> suggestions?
>
> Thanks!

Re: 98 TJ power loss & rough idle soon after startup
 

Thanks Bill. I had a go at getting the fault code per that link, but
got nothing. I guess I am in that 6 month period. I'll have a look
at replacing the crank position sensor anyway.

I'm curious though - what kind of a problem with that sensor would
cause this intermittent problem?


L.W.(ßill) ------ III <----------@cox.net> wrote in message news:<413FB013.D9CFC966@cox.net>...
> Your computer is in the limp mode. Try to find out what the fault
> code is by: http://minimopar.knizefamily.net/fault/ (Here's hoping
> you're not in that the about six month period that won't work for.)
> Ninety percent of the time it will be the Crankcase Position Sensor.
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> PaulT wrote:
> >
> > I'm having a problem with my '98 Wrangler, I6, manual transmission:
> >
> > Within 2 or 3 minutes of starting up, it develops a significant power
> > loss at speed, and at rest it idles very roughly at approx. 200 or 300
> > RPM. If I attempt to rev it up while this is happening, it hesitates
> > and backfires. If I just let it sit idling, it will sort itself out
> > after a couple of minutes (though occasionally it is bad enough that
> > it stalls). Alternatively, if I turn the engine off then restart it,
> > the problem goes away immediately (occasionally, it comes back, but
> > not as bad and a second restart cures it). This happens regardless of
> > the weather/temperature or the engine temperature, though it's often
> > not as bad if the engine is already warm.
> >
> > I recently gave it a service (oil, oil filter, plugs, and air filter
> > changed) - this had no effect on the problem.
> >
> > Has anyone seen and solved a problem like this before? Any
> > suggestions?
> >
> > Thanks!

Re: 98 TJ power loss & rough idle soon after startup
 

Thanks Bill. I had a go at getting the fault code per that link, but
got nothing. I guess I am in that 6 month period. I'll have a look
at replacing the crank position sensor anyway.

I'm curious though - what kind of a problem with that sensor would
cause this intermittent problem?


L.W.(ßill) ------ III <----------@cox.net> wrote in message news:<413FB013.D9CFC966@cox.net>...
> Your computer is in the limp mode. Try to find out what the fault
> code is by: http://minimopar.knizefamily.net/fault/ (Here's hoping
> you're not in that the about six month period that won't work for.)
> Ninety percent of the time it will be the Crankcase Position Sensor.
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> PaulT wrote:
> >
> > I'm having a problem with my '98 Wrangler, I6, manual transmission:
> >
> > Within 2 or 3 minutes of starting up, it develops a significant power
> > loss at speed, and at rest it idles very roughly at approx. 200 or 300
> > RPM. If I attempt to rev it up while this is happening, it hesitates
> > and backfires. If I just let it sit idling, it will sort itself out
> > after a couple of minutes (though occasionally it is bad enough that
> > it stalls). Alternatively, if I turn the engine off then restart it,
> > the problem goes away immediately (occasionally, it comes back, but
> > not as bad and a second restart cures it). This happens regardless of
> > the weather/temperature or the engine temperature, though it's often
> > not as bad if the engine is already warm.
> >
> > I recently gave it a service (oil, oil filter, plugs, and air filter
> > changed) - this had no effect on the problem.
> >
> > Has anyone seen and solved a problem like this before? Any
> > suggestions?
> >
> > Thanks!

Re: 98 TJ power loss & rough idle soon after startup
 

Thanks Bill. I had a go at getting the fault code per that link, but
got nothing. I guess I am in that 6 month period. I'll have a look
at replacing the crank position sensor anyway.

I'm curious though - what kind of a problem with that sensor would
cause this intermittent problem?


L.W.(ßill) ------ III <----------@cox.net> wrote in message news:<413FB013.D9CFC966@cox.net>...
> Your computer is in the limp mode. Try to find out what the fault
> code is by: http://minimopar.knizefamily.net/fault/ (Here's hoping
> you're not in that the about six month period that won't work for.)
> Ninety percent of the time it will be the Crankcase Position Sensor.
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> PaulT wrote:
> >
> > I'm having a problem with my '98 Wrangler, I6, manual transmission:
> >
> > Within 2 or 3 minutes of starting up, it develops a significant power
> > loss at speed, and at rest it idles very roughly at approx. 200 or 300
> > RPM. If I attempt to rev it up while this is happening, it hesitates
> > and backfires. If I just let it sit idling, it will sort itself out
> > after a couple of minutes (though occasionally it is bad enough that
> > it stalls). Alternatively, if I turn the engine off then restart it,
> > the problem goes away immediately (occasionally, it comes back, but
> > not as bad and a second restart cures it). This happens regardless of
> > the weather/temperature or the engine temperature, though it's often
> > not as bad if the engine is already warm.
> >
> > I recently gave it a service (oil, oil filter, plugs, and air filter
> > changed) - this had no effect on the problem.
> >
> > Has anyone seen and solved a problem like this before? Any
> > suggestions?
> >
> > Thanks!

Re: 98 TJ power loss & rough idle soon after startup
 

Intermittent usually means a dirty connection. These computer sensors
only use very low power so the slightest bit of oxidization interferes.

You can use a good contact cleaner for electronics on the pins and
socket to clean them and then a ring of dielectric grease on the rubber
seal on the plug to help keep more corrosion out.

The CPS is especially noted for that because the plug for it sits right
on top of the exhaust manifold so gets heat and cold shocked all the
time.

The TPS and other sensors plugged into the throttle body also get dirty
easy, so I clean and grease them all while I am at it.

In a pinch, WD40 is a fairly decent contact cleaner, but the real stuff
is better.

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

PaulT wrote:
>
> Thanks Bill. I had a go at getting the fault code per that link, but
> got nothing. I guess I am in that 6 month period. I'll have a look
> at replacing the crank position sensor anyway.
>
> I'm curious though - what kind of a problem with that sensor would
> cause this intermittent problem?
>
> L.W.(ßill) ------ III <----------@cox.net> wrote in message news:<413FB013.D9CFC966@cox.net>...
> > Your computer is in the limp mode. Try to find out what the fault
> > code is by: http://minimopar.knizefamily.net/fault/ (Here's hoping
> > you're not in that the about six month period that won't work for.)
> > Ninety percent of the time it will be the Crankcase Position Sensor.
> > God Bless America, ßill O|||||||O
> > mailto:-------------------- http://www.----------.com/
> >
> > PaulT wrote:
> > >
> > > I'm having a problem with my '98 Wrangler, I6, manual transmission:
> > >
> > > Within 2 or 3 minutes of starting up, it develops a significant power
> > > loss at speed, and at rest it idles very roughly at approx. 200 or 300
> > > RPM. If I attempt to rev it up while this is happening, it hesitates
> > > and backfires. If I just let it sit idling, it will sort itself out
> > > after a couple of minutes (though occasionally it is bad enough that
> > > it stalls). Alternatively, if I turn the engine off then restart it,
> > > the problem goes away immediately (occasionally, it comes back, but
> > > not as bad and a second restart cures it). This happens regardless of
> > > the weather/temperature or the engine temperature, though it's often
> > > not as bad if the engine is already warm.
> > >
> > > I recently gave it a service (oil, oil filter, plugs, and air filter
> > > changed) - this had no effect on the problem.
> > >
> > > Has anyone seen and solved a problem like this before? Any
> > > suggestions?
> > >
> > > Thanks!

Re: 98 TJ power loss & rough idle soon after startup
 

Intermittent usually means a dirty connection. These computer sensors
only use very low power so the slightest bit of oxidization interferes.

You can use a good contact cleaner for electronics on the pins and
socket to clean them and then a ring of dielectric grease on the rubber
seal on the plug to help keep more corrosion out.

The CPS is especially noted for that because the plug for it sits right
on top of the exhaust manifold so gets heat and cold shocked all the
time.

The TPS and other sensors plugged into the throttle body also get dirty
easy, so I clean and grease them all while I am at it.

In a pinch, WD40 is a fairly decent contact cleaner, but the real stuff
is better.

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

PaulT wrote:
>
> Thanks Bill. I had a go at getting the fault code per that link, but
> got nothing. I guess I am in that 6 month period. I'll have a look
> at replacing the crank position sensor anyway.
>
> I'm curious though - what kind of a problem with that sensor would
> cause this intermittent problem?
>
> L.W.(ßill) ------ III <----------@cox.net> wrote in message news:<413FB013.D9CFC966@cox.net>...
> > Your computer is in the limp mode. Try to find out what the fault
> > code is by: http://minimopar.knizefamily.net/fault/ (Here's hoping
> > you're not in that the about six month period that won't work for.)
> > Ninety percent of the time it will be the Crankcase Position Sensor.
> > God Bless America, ßill O|||||||O
> > mailto:-------------------- http://www.----------.com/
> >
> > PaulT wrote:
> > >
> > > I'm having a problem with my '98 Wrangler, I6, manual transmission:
> > >
> > > Within 2 or 3 minutes of starting up, it develops a significant power
> > > loss at speed, and at rest it idles very roughly at approx. 200 or 300
> > > RPM. If I attempt to rev it up while this is happening, it hesitates
> > > and backfires. If I just let it sit idling, it will sort itself out
> > > after a couple of minutes (though occasionally it is bad enough that
> > > it stalls). Alternatively, if I turn the engine off then restart it,
> > > the problem goes away immediately (occasionally, it comes back, but
> > > not as bad and a second restart cures it). This happens regardless of
> > > the weather/temperature or the engine temperature, though it's often
> > > not as bad if the engine is already warm.
> > >
> > > I recently gave it a service (oil, oil filter, plugs, and air filter
> > > changed) - this had no effect on the problem.
> > >
> > > Has anyone seen and solved a problem like this before? Any
> > > suggestions?
> > >
> > > Thanks!

Re: 98 TJ power loss & rough idle soon after startup
 

Intermittent usually means a dirty connection. These computer sensors
only use very low power so the slightest bit of oxidization interferes.

You can use a good contact cleaner for electronics on the pins and
socket to clean them and then a ring of dielectric grease on the rubber
seal on the plug to help keep more corrosion out.

The CPS is especially noted for that because the plug for it sits right
on top of the exhaust manifold so gets heat and cold shocked all the
time.

The TPS and other sensors plugged into the throttle body also get dirty
easy, so I clean and grease them all while I am at it.

In a pinch, WD40 is a fairly decent contact cleaner, but the real stuff
is better.

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

PaulT wrote:
>
> Thanks Bill. I had a go at getting the fault code per that link, but
> got nothing. I guess I am in that 6 month period. I'll have a look
> at replacing the crank position sensor anyway.
>
> I'm curious though - what kind of a problem with that sensor would
> cause this intermittent problem?
>
> L.W.(ßill) ------ III <----------@cox.net> wrote in message news:<413FB013.D9CFC966@cox.net>...
> > Your computer is in the limp mode. Try to find out what the fault
> > code is by: http://minimopar.knizefamily.net/fault/ (Here's hoping
> > you're not in that the about six month period that won't work for.)
> > Ninety percent of the time it will be the Crankcase Position Sensor.
> > God Bless America, ßill O|||||||O
> > mailto:-------------------- http://www.----------.com/
> >
> > PaulT wrote:
> > >
> > > I'm having a problem with my '98 Wrangler, I6, manual transmission:
> > >
> > > Within 2 or 3 minutes of starting up, it develops a significant power
> > > loss at speed, and at rest it idles very roughly at approx. 200 or 300
> > > RPM. If I attempt to rev it up while this is happening, it hesitates
> > > and backfires. If I just let it sit idling, it will sort itself out
> > > after a couple of minutes (though occasionally it is bad enough that
> > > it stalls). Alternatively, if I turn the engine off then restart it,
> > > the problem goes away immediately (occasionally, it comes back, but
> > > not as bad and a second restart cures it). This happens regardless of
> > > the weather/temperature or the engine temperature, though it's often
> > > not as bad if the engine is already warm.
> > >
> > > I recently gave it a service (oil, oil filter, plugs, and air filter
> > > changed) - this had no effect on the problem.
> > >
> > > Has anyone seen and solved a problem like this before? Any
> > > suggestions?
> > >
> > > Thanks!