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Still having high idle problem on 88 Jeep Comanche (4.0l)

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  #11  
Old   
Earle Horton
 
Posts: n/a

Default Re: Still having high idle problem on 88 Jeep Comanche (4.0l) - 03-28-2007 , 09:33 PM






That's the thinking. The theory is that your IAC has carbon in it, which is
making it function improperly, which is what is messing with your idle
speed. Cleaning the contacts for the various sensors mentioned can help
too.

Earle

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote

Quote:
I'm thinking it may not be too easy to haul the throttle body off, but I'd
imagine that would make it much easier to clean properly?

Clint

"Earle Horton" <apodo (AT) gracioso (DOT) usa> wrote in message
news:m5idncsNF6SeepTbnZ2dnUVZ_vShnZ2d (AT) comcast (DOT) com...
Agreed. The IAC too. (Idle Air Controller). This can get jammed with
tiny
amounts of deposits. I would probably use carburetor cleaner.

Earle

"Carl S" <carlsaiyed (AT) REMOVE (DOT) hotmail.com> wrote in message
news:R-6dnXAjo_RZfJTbnZ2dnUVZ_segnZ2d (AT) comcast (DOT) com...
Scrub till you'd eat from it.

Carl

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:S5lOh.82165$DN.39493 (AT) pd7urf2no (DOT) ..
Well, I got in there with a brush and solvent, and took off some
stuff
on
the sides (beside the butterfly valve, for lack of the technical
phrases).
But it's opening and closing easily, and it's stopping when it hits
the
metal stop on the outside of the throttle. But is it perfectly
clean?
No. Should I scrub some more?

Clint

"Earle Horton" <apodo (AT) gracioso (DOT) usa> wrote in message
news:zfOdnQqMyL_oSpTbnZ2dnUVZ_o-knZ2d (AT) comcast (DOT) com...
Have you cleaned the throttle body? It's real easy and will
eliminate
that
as a source of the problem. Oil in the CCV system doesn't help
either,
and
cleaning the orifices is in principle also easy.

Earle

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:3IjOh.81737$DN.58716 (AT) pd7urf2no (DOT) ..
So I'm getting good vacuum using the very imprecise "finger over
the
hose
end" at the CCV hose, and the TPS sensor goes from about 1 to 5
volts.
Is
there some other things I should check?

Today it behaved differently than usual, hitting close to 3000 rpm
while
"idling". Usually it starts at about 800rpm when I start it up,
and
stays
constant at about 1500.

Could having a bad CCV valve be causing my problem? I'm getting
some
oil
in
my air filter as well, and as per these websites, it seems that may
be
that
cause of the oil:
http://jeep.off-road.com/jeep/articl....jsp?id=257836
http://jeep.off-road.com/jeep/articl....jsp?id=257985

I did try sealing around the grommets with some RTV silicone, but
it
didn't
seem to make a difference.

I guess I KNOW that I need to fix the CCV hoses/valves, but can
this
be
causing my problem with the high idle? If nothing else, I'm
figuring
that
oil in the air filter probably isn't helping keep the throttle body
really
clean, since the oil can get into the air system from there.

Clint












Reply With Quote
  #12  
Old   
L.W. \(Bill\) Hughes III
 
Posts: n/a

Default Re: Still having high idle problem on 88 Jeep Comanche (4.0l) - 03-28-2007 , 09:50 PM






http://members.cox.net/wilsond/tb/tb.html
God Bless America, Bill 0|||||||0
mailto:LWHughes3rd (AT) aol (DOT) com http://www.billhughes.com/


"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote

Quote:
I'm thinking it may not be too easy to haul the throttle body off, but I'd
imagine that would make it much easier to clean properly?

Clint


--
Posted via a free Usenet account from http://www.teranews.com



Reply With Quote
  #13  
Old   
Clint
 
Posts: n/a

Default Re: Still having high idle problem on 88 Jeep Comanche (4.0l) - 03-28-2007 , 10:02 PM



This is probably a really dumb question, but how do you remove the linkages
from the throttle body? Some of the posts I've seen indicate it may just be
a simple ball/socket joint, which means I just didn't use a big enough
hammer (figuratively speaking, of course) on it. Thought I'd check in here
first, though.

Clint

"Carl S" <carlsaiyed (AT) REMOVE (DOT) hotmail.com> wrote

Quote:
It's only four bolts that hold the TB on, and the cables. Takes about 5
minutes to pull. Don't loose the cable clips, and be sure you make a note
of what cables go where.

Carl


"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:xxEOh.85181$zU1.26284 (AT) pd7urf1no (DOT) ..
I'm thinking it may not be too easy to haul the throttle body off, but
I'd imagine that would make it much easier to clean properly?

Clint

"Earle Horton" <apodo (AT) gracioso (DOT) usa> wrote in message
news:m5idncsNF6SeepTbnZ2dnUVZ_vShnZ2d (AT) comcast (DOT) com...
Agreed. The IAC too. (Idle Air Controller). This can get jammed with
tiny
amounts of deposits. I would probably use carburetor cleaner.

Earle

"Carl S" <carlsaiyed (AT) REMOVE (DOT) hotmail.com> wrote in message
news:R-6dnXAjo_RZfJTbnZ2dnUVZ_segnZ2d (AT) comcast (DOT) com...
Scrub till you'd eat from it.

Carl

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:S5lOh.82165$DN.39493 (AT) pd7urf2no (DOT) ..
Well, I got in there with a brush and solvent, and took off some
stuff
on
the sides (beside the butterfly valve, for lack of the technical
phrases).
But it's opening and closing easily, and it's stopping when it hits
the
metal stop on the outside of the throttle. But is it perfectly
clean?
No. Should I scrub some more?

Clint

"Earle Horton" <apodo (AT) gracioso (DOT) usa> wrote in message
news:zfOdnQqMyL_oSpTbnZ2dnUVZ_o-knZ2d (AT) comcast (DOT) com...
Have you cleaned the throttle body? It's real easy and will
eliminate
that
as a source of the problem. Oil in the CCV system doesn't help
either,
and
cleaning the orifices is in principle also easy.

Earle

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:3IjOh.81737$DN.58716 (AT) pd7urf2no (DOT) ..
So I'm getting good vacuum using the very imprecise "finger over
the
hose
end" at the CCV hose, and the TPS sensor goes from about 1 to 5
volts.
Is
there some other things I should check?

Today it behaved differently than usual, hitting close to 3000 rpm
while
"idling". Usually it starts at about 800rpm when I start it up,
and
stays
constant at about 1500.

Could having a bad CCV valve be causing my problem? I'm getting
some
oil
in
my air filter as well, and as per these websites, it seems that may
be
that
cause of the oil:
http://jeep.off-road.com/jeep/articl....jsp?id=257836
http://jeep.off-road.com/jeep/articl....jsp?id=257985

I did try sealing around the grommets with some RTV silicone, but
it
didn't
seem to make a difference.

I guess I KNOW that I need to fix the CCV hoses/valves, but can
this
be
causing my problem with the high idle? If nothing else, I'm
figuring
that
oil in the air filter probably isn't helping keep the throttle body
really
clean, since the oil can get into the air system from there.

Clint













Reply With Quote
  #14  
Old   
Mike Romain
 
Posts: n/a

Default Re: Still having high idle problem on 88 Jeep Comanche (4.0l) - 03-29-2007 , 09:02 AM



You are correct about looking for a vacuum line loose.

The CCV, if pulled off at the manifold will cause a steady high idle,
but normally it gets blocked which just pukes oil into the air filter.
It would be worth inspecting the rubber grommet where it enters the
manifold for cracks though.

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)

Clint wrote:
Quote:
BTW, this problem SEEMS to have started about the same time as I hauled
the old radiator and water pump out and replaced it. Could very easily
just be coincidence, though. I've tried checking all the vacuum hoses
in particular around the area I was working in, but nothing popped up.

I'm tempted to head out to a wrecker, and see about snagging an old
throttle body (preferably with sensors), just for S&G. Give me
something to swap out some parts to try seeing what's wrong.

So it's not seeming that bad CCV valves/hoses should be causing the high
idle, though?

Clint

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:3IjOh.81737$DN.58716 (AT) pd7urf2no (DOT) ..
So I'm getting good vacuum using the very imprecise "finger over the
hose end" at the CCV hose, and the TPS sensor goes from about 1 to 5
volts. Is there some other things I should check?

Today it behaved differently than usual, hitting close to 3000 rpm
while "idling". Usually it starts at about 800rpm when I start it up,
and stays constant at about 1500.

Could having a bad CCV valve be causing my problem? I'm getting some
oil in my air filter as well, and as per these websites, it seems that
may be that cause of the oil:
http://jeep.off-road.com/jeep/articl....jsp?id=257836
http://jeep.off-road.com/jeep/articl....jsp?id=257985

I did try sealing around the grommets with some RTV silicone, but it
didn't seem to make a difference.

I guess I KNOW that I need to fix the CCV hoses/valves, but can this
be causing my problem with the high idle? If nothing else, I'm
figuring that oil in the air filter probably isn't helping keep the
throttle body really clean, since the oil can get into the air system
from there.

Clint


Reply With Quote
  #15  
Old   
Clint
 
Posts: n/a

Default Re: Still having high idle problem on 88 Jeep Comanche (4.0l) - 03-30-2007 , 08:30 AM



No clues for getting the linkages off? Should I just pry a bit with a
screwdriver?

Clint

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote

Quote:
This is probably a really dumb question, but how do you remove the
linkages from the throttle body? Some of the posts I've seen indicate it
may just be a simple ball/socket joint, which means I just didn't use a
big enough hammer (figuratively speaking, of course) on it. Thought I'd
check in here first, though.

Clint

"Carl S" <carlsaiyed (AT) REMOVE (DOT) hotmail.com> wrote in message
news:u_WdncCka6PpgJbbnZ2dnUVZ_vmqnZ2d (AT) comcast (DOT) com...
It's only four bolts that hold the TB on, and the cables. Takes about 5
minutes to pull. Don't loose the cable clips, and be sure you make a note
of what cables go where.

Carl


"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:xxEOh.85181$zU1.26284 (AT) pd7urf1no (DOT) ..
I'm thinking it may not be too easy to haul the throttle body off, but
I'd imagine that would make it much easier to clean properly?

Clint

"Earle Horton" <apodo (AT) gracioso (DOT) usa> wrote in message
news:m5idncsNF6SeepTbnZ2dnUVZ_vShnZ2d (AT) comcast (DOT) com...
Agreed. The IAC too. (Idle Air Controller). This can get jammed with
tiny
amounts of deposits. I would probably use carburetor cleaner.

Earle

"Carl S" <carlsaiyed (AT) REMOVE (DOT) hotmail.com> wrote in message
news:R-6dnXAjo_RZfJTbnZ2dnUVZ_segnZ2d (AT) comcast (DOT) com...
Scrub till you'd eat from it.

Carl

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:S5lOh.82165$DN.39493 (AT) pd7urf2no (DOT) ..
Well, I got in there with a brush and solvent, and took off some
stuff
on
the sides (beside the butterfly valve, for lack of the technical
phrases).
But it's opening and closing easily, and it's stopping when it hits
the
metal stop on the outside of the throttle. But is it perfectly
clean?
No. Should I scrub some more?

Clint

"Earle Horton" <apodo (AT) gracioso (DOT) usa> wrote in message
news:zfOdnQqMyL_oSpTbnZ2dnUVZ_o-knZ2d (AT) comcast (DOT) com...
Have you cleaned the throttle body? It's real easy and will
eliminate
that
as a source of the problem. Oil in the CCV system doesn't help
either,
and
cleaning the orifices is in principle also easy.

Earle

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:3IjOh.81737$DN.58716 (AT) pd7urf2no (DOT) ..
So I'm getting good vacuum using the very imprecise "finger over
the
hose
end" at the CCV hose, and the TPS sensor goes from about 1 to 5
volts.
Is
there some other things I should check?

Today it behaved differently than usual, hitting close to 3000 rpm
while
"idling". Usually it starts at about 800rpm when I start it up,
and
stays
constant at about 1500.

Could having a bad CCV valve be causing my problem? I'm getting
some
oil
in
my air filter as well, and as per these websites, it seems that
may be
that
cause of the oil:
http://jeep.off-road.com/jeep/articl....jsp?id=257836
http://jeep.off-road.com/jeep/articl....jsp?id=257985

I did try sealing around the grommets with some RTV silicone, but
it
didn't
seem to make a difference.

I guess I KNOW that I need to fix the CCV hoses/valves, but can
this
be
causing my problem with the high idle? If nothing else, I'm
figuring
that
oil in the air filter probably isn't helping keep the throttle
body
really
clean, since the oil can get into the air system from there.

Clint














Reply With Quote
  #16  
Old   
Mike Romain
 
Posts: n/a

Default Re: Still having high idle problem on 88 Jeep Comanche (4.0l) - 03-30-2007 , 09:20 AM



Well..... sort of.....

You have to pull it off perfectly square with the backing plate on the
TB or one side of the clip will usually snap off. Old spring steel and
the slightest corrosion..... When you snap this clip, you can do a
decent paper clip bracket to hold it back on or you need to buy new
linkage... My 86 CJ7 has the paper clip fix thanks to Bill H.

I will go look at the 88's to make sure it is the same.

OK, nope, it is a plastic clip on our 88 with maybe a spring clip in the
end of it. It 'looks' like it should pull off square, but I don't know
for sure...

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)


Clint wrote:
Quote:
No clues for getting the linkages off? Should I just pry a bit with a
screwdriver?

Clint

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:b%FOh.84992$DN.3636 (AT) pd7urf2no (DOT) ..
This is probably a really dumb question, but how do you remove the
linkages from the throttle body? Some of the posts I've seen indicate
it may just be a simple ball/socket joint, which means I just didn't
use a big enough hammer (figuratively speaking, of course) on it.
Thought I'd check in here first, though.

Clint

"Carl S" <carlsaiyed (AT) REMOVE (DOT) hotmail.com> wrote in message
news:u_WdncCka6PpgJbbnZ2dnUVZ_vmqnZ2d (AT) comcast (DOT) com...
It's only four bolts that hold the TB on, and the cables. Takes about
5 minutes to pull. Don't loose the cable clips, and be sure you make
a note of what cables go where.

Carl


"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:xxEOh.85181$zU1.26284 (AT) pd7urf1no (DOT) ..
I'm thinking it may not be too easy to haul the throttle body off,
but I'd imagine that would make it much easier to clean properly?

Clint

"Earle Horton" <apodo (AT) gracioso (DOT) usa> wrote in message
news:m5idncsNF6SeepTbnZ2dnUVZ_vShnZ2d (AT) comcast (DOT) com...
Agreed. The IAC too. (Idle Air Controller). This can get jammed
with tiny
amounts of deposits. I would probably use carburetor cleaner.

Earle

"Carl S" <carlsaiyed (AT) REMOVE (DOT) hotmail.com> wrote in message
news:R-6dnXAjo_RZfJTbnZ2dnUVZ_segnZ2d (AT) comcast (DOT) com...
Scrub till you'd eat from it.

Carl

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:S5lOh.82165$DN.39493 (AT) pd7urf2no (DOT) ..
Well, I got in there with a brush and solvent, and took off some
stuff
on
the sides (beside the butterfly valve, for lack of the technical
phrases).
But it's opening and closing easily, and it's stopping when it
hits > the
metal stop on the outside of the throttle. But is it perfectly
clean?
No. Should I scrub some more?

Clint

"Earle Horton" <apodo (AT) gracioso (DOT) usa> wrote in message
news:zfOdnQqMyL_oSpTbnZ2dnUVZ_o-knZ2d (AT) comcast (DOT) com...
Have you cleaned the throttle body? It's real easy and will
eliminate
that
as a source of the problem. Oil in the CCV system doesn't help
either,
and
cleaning the orifices is in principle also easy.

Earle

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:3IjOh.81737$DN.58716 (AT) pd7urf2no (DOT) ..
So I'm getting good vacuum using the very imprecise "finger
over >>> the
hose
end" at the CCV hose, and the TPS sensor goes from about 1 to
5 >>> volts.
Is
there some other things I should check?

Today it behaved differently than usual, hitting close to 3000
rpm
while
"idling". Usually it starts at about 800rpm when I start it
up, >>> and
stays
constant at about 1500.

Could having a bad CCV valve be causing my problem? I'm
getting >>> some
oil
in
my air filter as well, and as per these websites, it seems
that >>> may be
that
cause of the oil:
http://jeep.off-road.com/jeep/articl....jsp?id=257836
http://jeep.off-road.com/jeep/articl....jsp?id=257985

I did try sealing around the grommets with some RTV silicone,
but >>> it
didn't
seem to make a difference.

I guess I KNOW that I need to fix the CCV hoses/valves, but
can >>> this
be
causing my problem with the high idle? If nothing else, I'm
figuring
that
oil in the air filter probably isn't helping keep the throttle
body
really
clean, since the oil can get into the air system from there.

Clint














Reply With Quote
  #17  
Old   
Clint
 
Posts: n/a

Default Re: Still having high idle problem on 88 Jeep Comanche (4.0l) - 03-30-2007 , 09:46 AM



Thanks, Mike. I appreciate you digging into it for me.

Clint

"Mike Romain" <romainm (AT) sympatico (DOT) ca> wrote

Quote:
Well..... sort of.....

You have to pull it off perfectly square with the backing plate on the TB
or one side of the clip will usually snap off. Old spring steel and the
slightest corrosion..... When you snap this clip, you can do a decent
paper clip bracket to hold it back on or you need to buy new linkage...
My 86 CJ7 has the paper clip fix thanks to Bill H.

I will go look at the 88's to make sure it is the same.

OK, nope, it is a plastic clip on our 88 with maybe a spring clip in the
end of it. It 'looks' like it should pull off square, but I don't know
for sure...

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)


Clint wrote:
No clues for getting the linkages off? Should I just pry a bit with a
screwdriver?

Clint

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:b%FOh.84992$DN.3636 (AT) pd7urf2no (DOT) ..
This is probably a really dumb question, but how do you remove the
linkages from the throttle body? Some of the posts I've seen indicate
it may just be a simple ball/socket joint, which means I just didn't use
a big enough hammer (figuratively speaking, of course) on it. Thought
I'd check in here first, though.

Clint

"Carl S" <carlsaiyed (AT) REMOVE (DOT) hotmail.com> wrote in message
news:u_WdncCka6PpgJbbnZ2dnUVZ_vmqnZ2d (AT) comcast (DOT) com...
It's only four bolts that hold the TB on, and the cables. Takes about 5
minutes to pull. Don't loose the cable clips, and be sure you make a
note of what cables go where.

Carl


"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:xxEOh.85181$zU1.26284 (AT) pd7urf1no (DOT) ..
I'm thinking it may not be too easy to haul the throttle body off, but
I'd imagine that would make it much easier to clean properly?

Clint

"Earle Horton" <apodo (AT) gracioso (DOT) usa> wrote in message
news:m5idncsNF6SeepTbnZ2dnUVZ_vShnZ2d (AT) comcast (DOT) com...
Agreed. The IAC too. (Idle Air Controller). This can get jammed
with tiny
amounts of deposits. I would probably use carburetor cleaner.

Earle

"Carl S" <carlsaiyed (AT) REMOVE (DOT) hotmail.com> wrote in message
news:R-6dnXAjo_RZfJTbnZ2dnUVZ_segnZ2d (AT) comcast (DOT) com...
Scrub till you'd eat from it.

Carl

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:S5lOh.82165$DN.39493 (AT) pd7urf2no (DOT) ..
Well, I got in there with a brush and solvent, and took off some
stuff
on
the sides (beside the butterfly valve, for lack of the technical
phrases).
But it's opening and closing easily, and it's stopping when it
hits > the
metal stop on the outside of the throttle. But is it perfectly
clean?
No. Should I scrub some more?

Clint

"Earle Horton" <apodo (AT) gracioso (DOT) usa> wrote in message
news:zfOdnQqMyL_oSpTbnZ2dnUVZ_o-knZ2d (AT) comcast (DOT) com...
Have you cleaned the throttle body? It's real easy and will
eliminate
that
as a source of the problem. Oil in the CCV system doesn't help
either,
and
cleaning the orifices is in principle also easy.

Earle

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote in message
news:3IjOh.81737$DN.58716 (AT) pd7urf2no (DOT) ..
So I'm getting good vacuum using the very imprecise "finger
over >>> the
hose
end" at the CCV hose, and the TPS sensor goes from about 1 to
5 >>> volts.
Is
there some other things I should check?

Today it behaved differently than usual, hitting close to 3000
rpm
while
"idling". Usually it starts at about 800rpm when I start it
up, >>> and
stays
constant at about 1500.

Could having a bad CCV valve be causing my problem? I'm
getting >>> some
oil
in
my air filter as well, and as per these websites, it seems
that >>> may be
that
cause of the oil:
http://jeep.off-road.com/jeep/articl....jsp?id=257836
http://jeep.off-road.com/jeep/articl....jsp?id=257985

I did try sealing around the grommets with some RTV silicone,
but >>> it
didn't
seem to make a difference.

I guess I KNOW that I need to fix the CCV hoses/valves, but
can >>> this
be
causing my problem with the high idle? If nothing else, I'm
figuring
that
oil in the air filter probably isn't helping keep the throttle
body
really
clean, since the oil can get into the air system from there.

Clint















Reply With Quote
  #18  
Old   
Clint
 
Posts: n/a

Default Re: Still having high idle problem on 88 Jeep Comanche (4.0l) - 03-31-2007 , 05:14 PM



So I did my thorough cleaning of the throttle body, and it seems to run
smoother and more consistent. Don't know about eating off it, but there's
no more black gunk in there. But now immediately after firing it up, it
goes up to about 2000 rpm, and sits there.

I tried unplugging the two sensors (one at a time) and then starting it up.
When I did that to the IAS, it started like I had my foot on the gas (rapid
increase in engine speed). Shut it down, plug in the IAS, then unplug the
TPS. Well, that made it run exactly as it did with it plugged in; start and
run at 2000 rpm. So I'm thinking the TPS is shot, and I should replace it.
Make sense? I had tried adjusting the TPS with no joy as well, even when I
went to one extreme to the other. I haven't re-measured the output of the
TPS; I'll probably do that later today. But it seems it should be doing
something useful.

Clint

"Clint" <cneufeld (AT) mysocks (DOT) shaw.ca> wrote

Quote:
So I'm getting good vacuum using the very imprecise "finger over the hose
end" at the CCV hose, and the TPS sensor goes from about 1 to 5 volts. Is
there some other things I should check?

Today it behaved differently than usual, hitting close to 3000 rpm while
"idling". Usually it starts at about 800rpm when I start it up, and stays
constant at about 1500.

Could having a bad CCV valve be causing my problem? I'm getting some oil
in my air filter as well, and as per these websites, it seems that may be
that cause of the oil:
http://jeep.off-road.com/jeep/articl....jsp?id=257836
http://jeep.off-road.com/jeep/articl....jsp?id=257985

I did try sealing around the grommets with some RTV silicone, but it
didn't seem to make a difference.

I guess I KNOW that I need to fix the CCV hoses/valves, but can this be
causing my problem with the high idle? If nothing else, I'm figuring that
oil in the air filter probably isn't helping keep the throttle body really
clean, since the oil can get into the air system from there.

Clint


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  #19  
Old   
Clint
 
Posts: n/a

Default Re: Still having high idle problem on 88 Jeep Comanche (4.0l) - 04-02-2007 , 01:27 PM



So I stopped by the local parts place, and they wanted $280 for the
sensor! The manual transmission one was twice as much as the
automatic one, and of course, I've got the more expensive of the two.
*sigh* I thought the automatic one had an extra electrical connector
on it? So shouldn't it be the more expensive of the two? Ah, well,
logic isn't required, I guess.

I checked a "parts recycler", and they had the automatic transmission
version in stock, but it was still $75, which seems pretty steep for a
used part like that. I think I'll have to find a "pick-your-part"
type place. I can yank it out in no time, at least.

Clint

On Mar 31, 4:14 pm, "Clint" <cneuf... (AT) mysocks (DOT) shaw.ca> wrote:
Quote:
So I did my thorough cleaning of the throttle body, and it seems to run
smoother and more consistent. Don't know about eating off it, but there's
no more black gunk in there. But now immediately after firing it up, it
goes up to about 2000 rpm, and sits there.

I tried unplugging the two sensors (one at a time) and then starting it up.
When I did that to the IAS, it started like I had my foot on the gas (rapid
increase in engine speed). Shut it down, plug in the IAS, then unplug the
TPS. Well, that made it run exactly as it did with it plugged in; start and
run at 2000 rpm. So I'm thinking the TPS is shot, and I should replace it.
Make sense? I had tried adjusting the TPS with no joy as well, even when I
went to one extreme to the other. I haven't re-measured the output of the
TPS; I'll probably do that later today. But it seems it should be doing
something useful.

Clint

"Clint" <cneuf... (AT) mysocks (DOT) shaw.ca> wrote in message

news:3IjOh.81737$DN.58716 (AT) pd7urf2no (DOT) ..



So I'm getting good vacuum using the very imprecise "finger over the hose
end" at the CCV hose, and the TPS sensor goes from about 1 to 5 volts. Is
there some other things I should check?

Today it behaved differently than usual, hitting close to 3000 rpm while
"idling". Usually it starts at about 800rpm when I start it up, and stays
constant at about 1500.

Could having a bad CCV valve be causing my problem? I'm getting some oil
in my air filter as well, and as per these websites, it seems that may be
that cause of the oil:
http://jeep.off-road.com/jeep/articl....jsp?id=257836
http://jeep.off-road.com/jeep/articl....jsp?id=257985

I did try sealing around the grommets with some RTV silicone, but it
didn't seem to make a difference.

I guess I KNOW that I need to fix the CCV hoses/valves, but can this be
causing my problem with the high idle? If nothing else, I'm figuring that
oil in the air filter probably isn't helping keep the throttle body really
clean, since the oil can get into the air system from there.

Clint- Hide quoted text -

- Show quoted text -



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  #20  
Old   
Will Honea
 
Posts: n/a

Default Re: Still having high idle problem on 88 Jeep Comanche (4.0l) - 04-03-2007 , 03:41 AM



Clint wrote:

Quote:
So I stopped by the local parts place, and they wanted $280 for the
sensor! The manual transmission one was twice as much as the
automatic one, and of course, I've got the more expensive of the two.
*sigh* I thought the automatic one had an extra electrical connector
on it? So shouldn't it be the more expensive of the two? Ah, well,
logic isn't required, I guess.

I checked a "parts recycler", and they had the automatic transmission
version in stock, but it was still $75, which seems pretty steep for a
used part like that. I think I'll have to find a "pick-your-part"
type place. I can yank it out in no time, at least.
I checked Advanced Auto Parts online and they get in the vicinity of $75 for
a new one - several suppliers to chose from.

Before you go throwing money at it, remove the old one and spray it well
with WD40 or contact cleaner. You should be able to get some to filter
inside. Get as close to the unit as possible and measure the resistance
between all the pins. That !!@#$% thing is a simple rheostat so if you
turn it as far as it goes in one direction, you should get several ohms
(not sure of the exact value - sorry) between one of the pins and the other
two. Leave one end of the ohm meter where it was and turn the thing about
half way. Now you should see about half the resistance at one of the pins.
Swap thing around to be sure you have contact between all 3 pins at some
point. I have been able to clean the wiper arm in a couple of them by
soaking the thing in WD40 for a days or so - the shaft is not sealed, so
the solvent will seep in - and it sure beats $75!

FYI, AA lists the same part for the 87-90 Comanche, Cherokee, and Wagoneer
with the 4.0 engine.

--
Will Honea
whonea (AT) yahoo (DOT) com


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