Re: low idle warm 90 jeep 4.0
 

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.

Re: low idle warm 90 jeep 4.0
 

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.

Re: low idle warm 90 jeep 4.0
 

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.

Re: low idle warm 90 jeep 4.0
 

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.

Re: low idle warm 90 jeep 4.0
 

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.

Re: low idle warm 90 jeep 4.0
 

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.

Re: low idle warm 90 jeep 4.0
 

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.

Re: low idle warm 90 jeep 4.0
 

Where is the CCV located? I'm not finding it in my book.

~Casper
'93 GC Ltd.

>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)

Re: low idle warm 90 jeep 4.0
 

Where is the CCV located? I'm not finding it in my book.

~Casper
'93 GC Ltd.

>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)

Re: low idle warm 90 jeep 4.0
 

Where is the CCV located? I'm not finding it in my book.

~Casper
'93 GC Ltd.

>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)