low idle warm 90 jeep 4.0
03-19-2006, 06:30 PM
#41
Guest
Posts: n/a
Re: low idle warm 90 jeep 4.0
90 XJ 4.0 does indeed have EGR. Just like your 88.
In message <441AF396.83C2B581@sympatico.ca>, "Mike Romain" wrote:
>The 4.0 doesn't have an EGR, just a CCV. When it's tube plugs, oil
>blows into the air filter.
>
>Mike
>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>88 Cherokee 235 BFG AT's
>Canadian Off Road Trips Photos: Non members can still view!
>Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>(More Off Road album links at bottom of the view page)
>
>JD Adams wrote:
>>
>> How long has it been since you've cleaned the throttle body? Most
>> don't ever do it at all. It could be a PCV valve that is damaged and
>> has dropped the valve portion down into the engine creating a big
>> vacuum leak, a really dirty throttle body or a bad spot on the TPS.
>> When you clean out the TB, use a very soft toothbrush and a soft cloth,
>> along with TB-friendly cleaner, not carb cleaner. Work with the engine
>> OFF, and take your time cleaning all the gunk off the sides and the
>> butterfly valve.
>>
>> While you're in there, pull your EGR valve and give that a good
>> cleaning as well. Sometimes they get so gunked up that they stick
>> open, creating a vaccum leak.
>>
>> Also, on those TPS's, aftermarket units are junk. Buy only an OEM
>> replacement. Same goes for the EGR valve, if you ever need to swap it
>> out. I found this all out the hard way.
In message <441AF396.83C2B581@sympatico.ca>, "Mike Romain" wrote:
>The 4.0 doesn't have an EGR, just a CCV. When it's tube plugs, oil
>blows into the air filter.
>
>Mike
>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>88 Cherokee 235 BFG AT's
>Canadian Off Road Trips Photos: Non members can still view!
>Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>(More Off Road album links at bottom of the view page)
>
>JD Adams wrote:
>>
>> How long has it been since you've cleaned the throttle body? Most
>> don't ever do it at all. It could be a PCV valve that is damaged and
>> has dropped the valve portion down into the engine creating a big
>> vacuum leak, a really dirty throttle body or a bad spot on the TPS.
>> When you clean out the TB, use a very soft toothbrush and a soft cloth,
>> along with TB-friendly cleaner, not carb cleaner. Work with the engine
>> OFF, and take your time cleaning all the gunk off the sides and the
>> butterfly valve.
>>
>> While you're in there, pull your EGR valve and give that a good
>> cleaning as well. Sometimes they get so gunked up that they stick
>> open, creating a vaccum leak.
>>
>> Also, on those TPS's, aftermarket units are junk. Buy only an OEM
>> replacement. Same goes for the EGR valve, if you ever need to swap it
>> out. I found this all out the hard way.
03-19-2006, 06:31 PM
#42
Guest
Posts: n/a
Re: low idle warm 90 jeep 4.0
Hi JD:
I don't think I have a PCV valve, but I do have an EGR which I
changed. I cleaned the throttle body valve not too long ago. The TPS
is a couple of years old. At that same time I changed the MAP sensor.
The Jeep runs fine and smooth axcept when it's hot-started for 2
minutes or so.
Something I've been suspecting:
When it's warm, the alternator puts out lower voltage. I think the
same time the fuel pump is pumping less pressure. Lowering RPM and
voltage and even lower pressure. I've had a pressure gauge on the
injection manifold. The pressure does drop, but the pressure regulator
does seem to work also, I suppose with no feedback of the pressure, but
just today I tested pulling the vacuum off this regulator, and the
engine does speed up, even with the line plugged. I think the O2 sensor
should quickly correct the rich mixture and lean it back out, but it
didn't. While doing this I noticed little change in voltage coming from
the O2 sensor.
Harry
I don't think I have a PCV valve, but I do have an EGR which I
changed. I cleaned the throttle body valve not too long ago. The TPS
is a couple of years old. At that same time I changed the MAP sensor.
The Jeep runs fine and smooth axcept when it's hot-started for 2
minutes or so.
Something I've been suspecting:
When it's warm, the alternator puts out lower voltage. I think the
same time the fuel pump is pumping less pressure. Lowering RPM and
voltage and even lower pressure. I've had a pressure gauge on the
injection manifold. The pressure does drop, but the pressure regulator
does seem to work also, I suppose with no feedback of the pressure, but
just today I tested pulling the vacuum off this regulator, and the
engine does speed up, even with the line plugged. I think the O2 sensor
should quickly correct the rich mixture and lean it back out, but it
didn't. While doing this I noticed little change in voltage coming from
the O2 sensor.
Harry
03-19-2006, 06:31 PM
#43
Guest
Posts: n/a
Re: low idle warm 90 jeep 4.0
Hi JD:
I don't think I have a PCV valve, but I do have an EGR which I
changed. I cleaned the throttle body valve not too long ago. The TPS
is a couple of years old. At that same time I changed the MAP sensor.
The Jeep runs fine and smooth axcept when it's hot-started for 2
minutes or so.
Something I've been suspecting:
When it's warm, the alternator puts out lower voltage. I think the
same time the fuel pump is pumping less pressure. Lowering RPM and
voltage and even lower pressure. I've had a pressure gauge on the
injection manifold. The pressure does drop, but the pressure regulator
does seem to work also, I suppose with no feedback of the pressure, but
just today I tested pulling the vacuum off this regulator, and the
engine does speed up, even with the line plugged. I think the O2 sensor
should quickly correct the rich mixture and lean it back out, but it
didn't. While doing this I noticed little change in voltage coming from
the O2 sensor.
Harry
I don't think I have a PCV valve, but I do have an EGR which I
changed. I cleaned the throttle body valve not too long ago. The TPS
is a couple of years old. At that same time I changed the MAP sensor.
The Jeep runs fine and smooth axcept when it's hot-started for 2
minutes or so.
Something I've been suspecting:
When it's warm, the alternator puts out lower voltage. I think the
same time the fuel pump is pumping less pressure. Lowering RPM and
voltage and even lower pressure. I've had a pressure gauge on the
injection manifold. The pressure does drop, but the pressure regulator
does seem to work also, I suppose with no feedback of the pressure, but
just today I tested pulling the vacuum off this regulator, and the
engine does speed up, even with the line plugged. I think the O2 sensor
should quickly correct the rich mixture and lean it back out, but it
didn't. While doing this I noticed little change in voltage coming from
the O2 sensor.
Harry
03-19-2006, 06:31 PM
#44
Guest
Posts: n/a
Re: low idle warm 90 jeep 4.0
Hi JD:
I don't think I have a PCV valve, but I do have an EGR which I
changed. I cleaned the throttle body valve not too long ago. The TPS
is a couple of years old. At that same time I changed the MAP sensor.
The Jeep runs fine and smooth axcept when it's hot-started for 2
minutes or so.
Something I've been suspecting:
When it's warm, the alternator puts out lower voltage. I think the
same time the fuel pump is pumping less pressure. Lowering RPM and
voltage and even lower pressure. I've had a pressure gauge on the
injection manifold. The pressure does drop, but the pressure regulator
does seem to work also, I suppose with no feedback of the pressure, but
just today I tested pulling the vacuum off this regulator, and the
engine does speed up, even with the line plugged. I think the O2 sensor
should quickly correct the rich mixture and lean it back out, but it
didn't. While doing this I noticed little change in voltage coming from
the O2 sensor.
Harry
I don't think I have a PCV valve, but I do have an EGR which I
changed. I cleaned the throttle body valve not too long ago. The TPS
is a couple of years old. At that same time I changed the MAP sensor.
The Jeep runs fine and smooth axcept when it's hot-started for 2
minutes or so.
Something I've been suspecting:
When it's warm, the alternator puts out lower voltage. I think the
same time the fuel pump is pumping less pressure. Lowering RPM and
voltage and even lower pressure. I've had a pressure gauge on the
injection manifold. The pressure does drop, but the pressure regulator
does seem to work also, I suppose with no feedback of the pressure, but
just today I tested pulling the vacuum off this regulator, and the
engine does speed up, even with the line plugged. I think the O2 sensor
should quickly correct the rich mixture and lean it back out, but it
didn't. While doing this I noticed little change in voltage coming from
the O2 sensor.
Harry
03-19-2006, 06:31 PM
#45
Guest
Posts: n/a
Re: low idle warm 90 jeep 4.0
Hi JD:
I don't think I have a PCV valve, but I do have an EGR which I
changed. I cleaned the throttle body valve not too long ago. The TPS
is a couple of years old. At that same time I changed the MAP sensor.
The Jeep runs fine and smooth axcept when it's hot-started for 2
minutes or so.
Something I've been suspecting:
When it's warm, the alternator puts out lower voltage. I think the
same time the fuel pump is pumping less pressure. Lowering RPM and
voltage and even lower pressure. I've had a pressure gauge on the
injection manifold. The pressure does drop, but the pressure regulator
does seem to work also, I suppose with no feedback of the pressure, but
just today I tested pulling the vacuum off this regulator, and the
engine does speed up, even with the line plugged. I think the O2 sensor
should quickly correct the rich mixture and lean it back out, but it
didn't. While doing this I noticed little change in voltage coming from
the O2 sensor.
Harry
I don't think I have a PCV valve, but I do have an EGR which I
changed. I cleaned the throttle body valve not too long ago. The TPS
is a couple of years old. At that same time I changed the MAP sensor.
The Jeep runs fine and smooth axcept when it's hot-started for 2
minutes or so.
Something I've been suspecting:
When it's warm, the alternator puts out lower voltage. I think the
same time the fuel pump is pumping less pressure. Lowering RPM and
voltage and even lower pressure. I've had a pressure gauge on the
injection manifold. The pressure does drop, but the pressure regulator
does seem to work also, I suppose with no feedback of the pressure, but
just today I tested pulling the vacuum off this regulator, and the
engine does speed up, even with the line plugged. I think the O2 sensor
should quickly correct the rich mixture and lean it back out, but it
didn't. While doing this I noticed little change in voltage coming from
the O2 sensor.
Harry
03-19-2006, 06:37 PM
#46
Guest
Posts: n/a
Re: low idle warm 90 jeep 4.0
What are you going on about now... Our 88 has the CCV tube, I have
already had to clean it out...
Mike
bllsht wrote:
>
> 90 XJ 4.0 does indeed have EGR. Just like your 88.
>
> In message <441AF396.83C2B581@sympatico.ca>, "Mike Romain" wrote:
>
> >The 4.0 doesn't have an EGR, just a CCV. When it's tube plugs, oil
> >blows into the air filter.
> >
> >Mike
> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >88 Cherokee 235 BFG AT's
> >Canadian Off Road Trips Photos: Non members can still view!
> >Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> >(More Off Road album links at bottom of the view page)
> >
> >JD Adams wrote:
> >>
> >> How long has it been since you've cleaned the throttle body? Most
> >> don't ever do it at all. It could be a PCV valve that is damaged and
> >> has dropped the valve portion down into the engine creating a big
> >> vacuum leak, a really dirty throttle body or a bad spot on the TPS.
> >> When you clean out the TB, use a very soft toothbrush and a soft cloth,
> >> along with TB-friendly cleaner, not carb cleaner. Work with the engine
> >> OFF, and take your time cleaning all the gunk off the sides and the
> >> butterfly valve.
> >>
> >> While you're in there, pull your EGR valve and give that a good
> >> cleaning as well. Sometimes they get so gunked up that they stick
> >> open, creating a vaccum leak.
> >>
> >> Also, on those TPS's, aftermarket units are junk. Buy only an OEM
> >> replacement. Same goes for the EGR valve, if you ever need to swap it
> >> out. I found this all out the hard way.
already had to clean it out...
Mike
bllsht wrote:
>
> 90 XJ 4.0 does indeed have EGR. Just like your 88.
>
> In message <441AF396.83C2B581@sympatico.ca>, "Mike Romain" wrote:
>
> >The 4.0 doesn't have an EGR, just a CCV. When it's tube plugs, oil
> >blows into the air filter.
> >
> >Mike
> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >88 Cherokee 235 BFG AT's
> >Canadian Off Road Trips Photos: Non members can still view!
> >Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> >(More Off Road album links at bottom of the view page)
> >
> >JD Adams wrote:
> >>
> >> How long has it been since you've cleaned the throttle body? Most
> >> don't ever do it at all. It could be a PCV valve that is damaged and
> >> has dropped the valve portion down into the engine creating a big
> >> vacuum leak, a really dirty throttle body or a bad spot on the TPS.
> >> When you clean out the TB, use a very soft toothbrush and a soft cloth,
> >> along with TB-friendly cleaner, not carb cleaner. Work with the engine
> >> OFF, and take your time cleaning all the gunk off the sides and the
> >> butterfly valve.
> >>
> >> While you're in there, pull your EGR valve and give that a good
> >> cleaning as well. Sometimes they get so gunked up that they stick
> >> open, creating a vaccum leak.
> >>
> >> Also, on those TPS's, aftermarket units are junk. Buy only an OEM
> >> replacement. Same goes for the EGR valve, if you ever need to swap it
> >> out. I found this all out the hard way.
03-19-2006, 06:37 PM
#47
Guest
Posts: n/a
Re: low idle warm 90 jeep 4.0
What are you going on about now... Our 88 has the CCV tube, I have
already had to clean it out...
Mike
bllsht wrote:
>
> 90 XJ 4.0 does indeed have EGR. Just like your 88.
>
> In message <441AF396.83C2B581@sympatico.ca>, "Mike Romain" wrote:
>
> >The 4.0 doesn't have an EGR, just a CCV. When it's tube plugs, oil
> >blows into the air filter.
> >
> >Mike
> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >88 Cherokee 235 BFG AT's
> >Canadian Off Road Trips Photos: Non members can still view!
> >Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> >(More Off Road album links at bottom of the view page)
> >
> >JD Adams wrote:
> >>
> >> How long has it been since you've cleaned the throttle body? Most
> >> don't ever do it at all. It could be a PCV valve that is damaged and
> >> has dropped the valve portion down into the engine creating a big
> >> vacuum leak, a really dirty throttle body or a bad spot on the TPS.
> >> When you clean out the TB, use a very soft toothbrush and a soft cloth,
> >> along with TB-friendly cleaner, not carb cleaner. Work with the engine
> >> OFF, and take your time cleaning all the gunk off the sides and the
> >> butterfly valve.
> >>
> >> While you're in there, pull your EGR valve and give that a good
> >> cleaning as well. Sometimes they get so gunked up that they stick
> >> open, creating a vaccum leak.
> >>
> >> Also, on those TPS's, aftermarket units are junk. Buy only an OEM
> >> replacement. Same goes for the EGR valve, if you ever need to swap it
> >> out. I found this all out the hard way.
already had to clean it out...
Mike
bllsht wrote:
>
> 90 XJ 4.0 does indeed have EGR. Just like your 88.
>
> In message <441AF396.83C2B581@sympatico.ca>, "Mike Romain" wrote:
>
> >The 4.0 doesn't have an EGR, just a CCV. When it's tube plugs, oil
> >blows into the air filter.
> >
> >Mike
> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >88 Cherokee 235 BFG AT's
> >Canadian Off Road Trips Photos: Non members can still view!
> >Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> >(More Off Road album links at bottom of the view page)
> >
> >JD Adams wrote:
> >>
> >> How long has it been since you've cleaned the throttle body? Most
> >> don't ever do it at all. It could be a PCV valve that is damaged and
> >> has dropped the valve portion down into the engine creating a big
> >> vacuum leak, a really dirty throttle body or a bad spot on the TPS.
> >> When you clean out the TB, use a very soft toothbrush and a soft cloth,
> >> along with TB-friendly cleaner, not carb cleaner. Work with the engine
> >> OFF, and take your time cleaning all the gunk off the sides and the
> >> butterfly valve.
> >>
> >> While you're in there, pull your EGR valve and give that a good
> >> cleaning as well. Sometimes they get so gunked up that they stick
> >> open, creating a vaccum leak.
> >>
> >> Also, on those TPS's, aftermarket units are junk. Buy only an OEM
> >> replacement. Same goes for the EGR valve, if you ever need to swap it
> >> out. I found this all out the hard way.
03-19-2006, 06:37 PM
#48
Guest
Posts: n/a
Re: low idle warm 90 jeep 4.0
What are you going on about now... Our 88 has the CCV tube, I have
already had to clean it out...
Mike
bllsht wrote:
>
> 90 XJ 4.0 does indeed have EGR. Just like your 88.
>
> In message <441AF396.83C2B581@sympatico.ca>, "Mike Romain" wrote:
>
> >The 4.0 doesn't have an EGR, just a CCV. When it's tube plugs, oil
> >blows into the air filter.
> >
> >Mike
> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >88 Cherokee 235 BFG AT's
> >Canadian Off Road Trips Photos: Non members can still view!
> >Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> >(More Off Road album links at bottom of the view page)
> >
> >JD Adams wrote:
> >>
> >> How long has it been since you've cleaned the throttle body? Most
> >> don't ever do it at all. It could be a PCV valve that is damaged and
> >> has dropped the valve portion down into the engine creating a big
> >> vacuum leak, a really dirty throttle body or a bad spot on the TPS.
> >> When you clean out the TB, use a very soft toothbrush and a soft cloth,
> >> along with TB-friendly cleaner, not carb cleaner. Work with the engine
> >> OFF, and take your time cleaning all the gunk off the sides and the
> >> butterfly valve.
> >>
> >> While you're in there, pull your EGR valve and give that a good
> >> cleaning as well. Sometimes they get so gunked up that they stick
> >> open, creating a vaccum leak.
> >>
> >> Also, on those TPS's, aftermarket units are junk. Buy only an OEM
> >> replacement. Same goes for the EGR valve, if you ever need to swap it
> >> out. I found this all out the hard way.
already had to clean it out...
Mike
bllsht wrote:
>
> 90 XJ 4.0 does indeed have EGR. Just like your 88.
>
> In message <441AF396.83C2B581@sympatico.ca>, "Mike Romain" wrote:
>
> >The 4.0 doesn't have an EGR, just a CCV. When it's tube plugs, oil
> >blows into the air filter.
> >
> >Mike
> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >88 Cherokee 235 BFG AT's
> >Canadian Off Road Trips Photos: Non members can still view!
> >Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> >(More Off Road album links at bottom of the view page)
> >
> >JD Adams wrote:
> >>
> >> How long has it been since you've cleaned the throttle body? Most
> >> don't ever do it at all. It could be a PCV valve that is damaged and
> >> has dropped the valve portion down into the engine creating a big
> >> vacuum leak, a really dirty throttle body or a bad spot on the TPS.
> >> When you clean out the TB, use a very soft toothbrush and a soft cloth,
> >> along with TB-friendly cleaner, not carb cleaner. Work with the engine
> >> OFF, and take your time cleaning all the gunk off the sides and the
> >> butterfly valve.
> >>
> >> While you're in there, pull your EGR valve and give that a good
> >> cleaning as well. Sometimes they get so gunked up that they stick
> >> open, creating a vaccum leak.
> >>
> >> Also, on those TPS's, aftermarket units are junk. Buy only an OEM
> >> replacement. Same goes for the EGR valve, if you ever need to swap it
> >> out. I found this all out the hard way.
03-19-2006, 06:37 PM
#49
Guest
Posts: n/a
Re: low idle warm 90 jeep 4.0
What are you going on about now... Our 88 has the CCV tube, I have
already had to clean it out...
Mike
bllsht wrote:
>
> 90 XJ 4.0 does indeed have EGR. Just like your 88.
>
> In message <441AF396.83C2B581@sympatico.ca>, "Mike Romain" wrote:
>
> >The 4.0 doesn't have an EGR, just a CCV. When it's tube plugs, oil
> >blows into the air filter.
> >
> >Mike
> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >88 Cherokee 235 BFG AT's
> >Canadian Off Road Trips Photos: Non members can still view!
> >Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> >(More Off Road album links at bottom of the view page)
> >
> >JD Adams wrote:
> >>
> >> How long has it been since you've cleaned the throttle body? Most
> >> don't ever do it at all. It could be a PCV valve that is damaged and
> >> has dropped the valve portion down into the engine creating a big
> >> vacuum leak, a really dirty throttle body or a bad spot on the TPS.
> >> When you clean out the TB, use a very soft toothbrush and a soft cloth,
> >> along with TB-friendly cleaner, not carb cleaner. Work with the engine
> >> OFF, and take your time cleaning all the gunk off the sides and the
> >> butterfly valve.
> >>
> >> While you're in there, pull your EGR valve and give that a good
> >> cleaning as well. Sometimes they get so gunked up that they stick
> >> open, creating a vaccum leak.
> >>
> >> Also, on those TPS's, aftermarket units are junk. Buy only an OEM
> >> replacement. Same goes for the EGR valve, if you ever need to swap it
> >> out. I found this all out the hard way.
already had to clean it out...
Mike
bllsht wrote:
>
> 90 XJ 4.0 does indeed have EGR. Just like your 88.
>
> In message <441AF396.83C2B581@sympatico.ca>, "Mike Romain" wrote:
>
> >The 4.0 doesn't have an EGR, just a CCV. When it's tube plugs, oil
> >blows into the air filter.
> >
> >Mike
> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >88 Cherokee 235 BFG AT's
> >Canadian Off Road Trips Photos: Non members can still view!
> >Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> >(More Off Road album links at bottom of the view page)
> >
> >JD Adams wrote:
> >>
> >> How long has it been since you've cleaned the throttle body? Most
> >> don't ever do it at all. It could be a PCV valve that is damaged and
> >> has dropped the valve portion down into the engine creating a big
> >> vacuum leak, a really dirty throttle body or a bad spot on the TPS.
> >> When you clean out the TB, use a very soft toothbrush and a soft cloth,
> >> along with TB-friendly cleaner, not carb cleaner. Work with the engine
> >> OFF, and take your time cleaning all the gunk off the sides and the
> >> butterfly valve.
> >>
> >> While you're in there, pull your EGR valve and give that a good
> >> cleaning as well. Sometimes they get so gunked up that they stick
> >> open, creating a vaccum leak.
> >>
> >> Also, on those TPS's, aftermarket units are junk. Buy only an OEM
> >> replacement. Same goes for the EGR valve, if you ever need to swap it
> >> out. I found this all out the hard way.
03-19-2006, 06:38 PM
#50
Guest
Posts: n/a
Re: low idle warm 90 jeep 4.0
You are right, the letters got messed up in my head...
Mike
bllsht wrote:
>
> 90 XJ 4.0 does indeed have EGR. Just like your 88.
>
> In message <441AF396.83C2B581@sympatico.ca>, "Mike Romain" wrote:
>
> >The 4.0 doesn't have an EGR, just a CCV. When it's tube plugs, oil
> >blows into the air filter.
> >
> >Mike
> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >88 Cherokee 235 BFG AT's
> >Canadian Off Road Trips Photos: Non members can still view!
> >Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> >(More Off Road album links at bottom of the view page)
> >
> >JD Adams wrote:
> >>
> >> How long has it been since you've cleaned the throttle body? Most
> >> don't ever do it at all. It could be a PCV valve that is damaged and
> >> has dropped the valve portion down into the engine creating a big
> >> vacuum leak, a really dirty throttle body or a bad spot on the TPS.
> >> When you clean out the TB, use a very soft toothbrush and a soft cloth,
> >> along with TB-friendly cleaner, not carb cleaner. Work with the engine
> >> OFF, and take your time cleaning all the gunk off the sides and the
> >> butterfly valve.
> >>
> >> While you're in there, pull your EGR valve and give that a good
> >> cleaning as well. Sometimes they get so gunked up that they stick
> >> open, creating a vaccum leak.
> >>
> >> Also, on those TPS's, aftermarket units are junk. Buy only an OEM
> >> replacement. Same goes for the EGR valve, if you ever need to swap it
> >> out. I found this all out the hard way.
Mike
bllsht wrote:
>
> 90 XJ 4.0 does indeed have EGR. Just like your 88.
>
> In message <441AF396.83C2B581@sympatico.ca>, "Mike Romain" wrote:
>
> >The 4.0 doesn't have an EGR, just a CCV. When it's tube plugs, oil
> >blows into the air filter.
> >
> >Mike
> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >88 Cherokee 235 BFG AT's
> >Canadian Off Road Trips Photos: Non members can still view!
> >Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> >(More Off Road album links at bottom of the view page)
> >
> >JD Adams wrote:
> >>
> >> How long has it been since you've cleaned the throttle body? Most
> >> don't ever do it at all. It could be a PCV valve that is damaged and
> >> has dropped the valve portion down into the engine creating a big
> >> vacuum leak, a really dirty throttle body or a bad spot on the TPS.
> >> When you clean out the TB, use a very soft toothbrush and a soft cloth,
> >> along with TB-friendly cleaner, not carb cleaner. Work with the engine
> >> OFF, and take your time cleaning all the gunk off the sides and the
> >> butterfly valve.
> >>
> >> While you're in there, pull your EGR valve and give that a good
> >> cleaning as well. Sometimes they get so gunked up that they stick
> >> open, creating a vaccum leak.
> >>
> >> Also, on those TPS's, aftermarket units are junk. Buy only an OEM
> >> replacement. Same goes for the EGR valve, if you ever need to swap it
> >> out. I found this all out the hard way.