Idle setting on 4.0 TJ
Guest
Posts: n/a
Re: Idle setting on 4.0 TJ
tps sending the incorrect info to the pcm.
common failure
Dalewhite wrote:
> My idle has decided to run amok. My Jeep mechanic guru has swapped out the
> "idle air control motor" and it seems to make no difference. The engine will
> idle properly in the 6-700rpm range for a while then it will surge to anywhere
> between 1000 and 2000rpm and remain there indefinitely. The only way I have
> been able to limit the rpms to a manageble range is by blocking off a major
> part of the "idle air control passage inlet" (ref. page 14-45, SERVICE MANUAL ,
> JEEP WRANGLER). Can anyone suggest a procedure to isolate and identify the
> problem?
> tia dw
common failure
Dalewhite wrote:
> My idle has decided to run amok. My Jeep mechanic guru has swapped out the
> "idle air control motor" and it seems to make no difference. The engine will
> idle properly in the 6-700rpm range for a while then it will surge to anywhere
> between 1000 and 2000rpm and remain there indefinitely. The only way I have
> been able to limit the rpms to a manageble range is by blocking off a major
> part of the "idle air control passage inlet" (ref. page 14-45, SERVICE MANUAL ,
> JEEP WRANGLER). Can anyone suggest a procedure to isolate and identify the
> problem?
> tia dw
Guest
Posts: n/a
Re: Idle setting on 4.0 TJ
tps sending the incorrect info to the pcm.
common failure
Dalewhite wrote:
> My idle has decided to run amok. My Jeep mechanic guru has swapped out the
> "idle air control motor" and it seems to make no difference. The engine will
> idle properly in the 6-700rpm range for a while then it will surge to anywhere
> between 1000 and 2000rpm and remain there indefinitely. The only way I have
> been able to limit the rpms to a manageble range is by blocking off a major
> part of the "idle air control passage inlet" (ref. page 14-45, SERVICE MANUAL ,
> JEEP WRANGLER). Can anyone suggest a procedure to isolate and identify the
> problem?
> tia dw
common failure
Dalewhite wrote:
> My idle has decided to run amok. My Jeep mechanic guru has swapped out the
> "idle air control motor" and it seems to make no difference. The engine will
> idle properly in the 6-700rpm range for a while then it will surge to anywhere
> between 1000 and 2000rpm and remain there indefinitely. The only way I have
> been able to limit the rpms to a manageble range is by blocking off a major
> part of the "idle air control passage inlet" (ref. page 14-45, SERVICE MANUAL ,
> JEEP WRANGLER). Can anyone suggest a procedure to isolate and identify the
> problem?
> tia dw
Guest
Posts: n/a
Re: Idle setting on 4.0 TJ
mic canic did pass the time by typing:
> tps sending the incorrect info to the pcm.
> common failure
>
> Dalewhite wrote:
>
>> My idle has decided to run amok. My Jeep mechanic guru has swapped out the
>> "idle air control motor" and it seems to make no difference. The engine will
>> idle properly in the 6-700rpm range for a while then it will surge to
>> anywhere between 1000 and 2000rpm and remain there indefinitely. The only
>> way I have been able to limit the rpms to a manageble range is by blocking
>> off a major part of the "idle air control passage inlet" (ref. page 14-45,
>> SERVICE MANUAL , JEEP WRANGLER). Can anyone suggest a procedure to isolate
>> and identify the problem?
>> tia dw
Try this.
Backprobe (i.e. don't disconnect) the center pin on the TPS sensor.
Measure the voltage with the ignition on, engine not running.
It should be >200 milliVolts with the throttle closed,
< 4.8 Volts with the throttle wide open,
and butter smooth as you change between the two.
If it jumps it's toast.
If you don't get a good high reading, measure the outer two
wires. Should have 5V on them. (don't short these wires or
you will frag the computer)
--
DougW
> tps sending the incorrect info to the pcm.
> common failure
>
> Dalewhite wrote:
>
>> My idle has decided to run amok. My Jeep mechanic guru has swapped out the
>> "idle air control motor" and it seems to make no difference. The engine will
>> idle properly in the 6-700rpm range for a while then it will surge to
>> anywhere between 1000 and 2000rpm and remain there indefinitely. The only
>> way I have been able to limit the rpms to a manageble range is by blocking
>> off a major part of the "idle air control passage inlet" (ref. page 14-45,
>> SERVICE MANUAL , JEEP WRANGLER). Can anyone suggest a procedure to isolate
>> and identify the problem?
>> tia dw
Try this.
Backprobe (i.e. don't disconnect) the center pin on the TPS sensor.
Measure the voltage with the ignition on, engine not running.
It should be >200 milliVolts with the throttle closed,
< 4.8 Volts with the throttle wide open,
and butter smooth as you change between the two.
If it jumps it's toast.
If you don't get a good high reading, measure the outer two
wires. Should have 5V on them. (don't short these wires or
you will frag the computer)
--
DougW
Guest
Posts: n/a
Re: Idle setting on 4.0 TJ
mic canic did pass the time by typing:
> tps sending the incorrect info to the pcm.
> common failure
>
> Dalewhite wrote:
>
>> My idle has decided to run amok. My Jeep mechanic guru has swapped out the
>> "idle air control motor" and it seems to make no difference. The engine will
>> idle properly in the 6-700rpm range for a while then it will surge to
>> anywhere between 1000 and 2000rpm and remain there indefinitely. The only
>> way I have been able to limit the rpms to a manageble range is by blocking
>> off a major part of the "idle air control passage inlet" (ref. page 14-45,
>> SERVICE MANUAL , JEEP WRANGLER). Can anyone suggest a procedure to isolate
>> and identify the problem?
>> tia dw
Try this.
Backprobe (i.e. don't disconnect) the center pin on the TPS sensor.
Measure the voltage with the ignition on, engine not running.
It should be >200 milliVolts with the throttle closed,
< 4.8 Volts with the throttle wide open,
and butter smooth as you change between the two.
If it jumps it's toast.
If you don't get a good high reading, measure the outer two
wires. Should have 5V on them. (don't short these wires or
you will frag the computer)
--
DougW
> tps sending the incorrect info to the pcm.
> common failure
>
> Dalewhite wrote:
>
>> My idle has decided to run amok. My Jeep mechanic guru has swapped out the
>> "idle air control motor" and it seems to make no difference. The engine will
>> idle properly in the 6-700rpm range for a while then it will surge to
>> anywhere between 1000 and 2000rpm and remain there indefinitely. The only
>> way I have been able to limit the rpms to a manageble range is by blocking
>> off a major part of the "idle air control passage inlet" (ref. page 14-45,
>> SERVICE MANUAL , JEEP WRANGLER). Can anyone suggest a procedure to isolate
>> and identify the problem?
>> tia dw
Try this.
Backprobe (i.e. don't disconnect) the center pin on the TPS sensor.
Measure the voltage with the ignition on, engine not running.
It should be >200 milliVolts with the throttle closed,
< 4.8 Volts with the throttle wide open,
and butter smooth as you change between the two.
If it jumps it's toast.
If you don't get a good high reading, measure the outer two
wires. Should have 5V on them. (don't short these wires or
you will frag the computer)
--
DougW
Guest
Posts: n/a
Re: Idle setting on 4.0 TJ
mic canic did pass the time by typing:
> tps sending the incorrect info to the pcm.
> common failure
>
> Dalewhite wrote:
>
>> My idle has decided to run amok. My Jeep mechanic guru has swapped out the
>> "idle air control motor" and it seems to make no difference. The engine will
>> idle properly in the 6-700rpm range for a while then it will surge to
>> anywhere between 1000 and 2000rpm and remain there indefinitely. The only
>> way I have been able to limit the rpms to a manageble range is by blocking
>> off a major part of the "idle air control passage inlet" (ref. page 14-45,
>> SERVICE MANUAL , JEEP WRANGLER). Can anyone suggest a procedure to isolate
>> and identify the problem?
>> tia dw
Try this.
Backprobe (i.e. don't disconnect) the center pin on the TPS sensor.
Measure the voltage with the ignition on, engine not running.
It should be >200 milliVolts with the throttle closed,
< 4.8 Volts with the throttle wide open,
and butter smooth as you change between the two.
If it jumps it's toast.
If you don't get a good high reading, measure the outer two
wires. Should have 5V on them. (don't short these wires or
you will frag the computer)
--
DougW
> tps sending the incorrect info to the pcm.
> common failure
>
> Dalewhite wrote:
>
>> My idle has decided to run amok. My Jeep mechanic guru has swapped out the
>> "idle air control motor" and it seems to make no difference. The engine will
>> idle properly in the 6-700rpm range for a while then it will surge to
>> anywhere between 1000 and 2000rpm and remain there indefinitely. The only
>> way I have been able to limit the rpms to a manageble range is by blocking
>> off a major part of the "idle air control passage inlet" (ref. page 14-45,
>> SERVICE MANUAL , JEEP WRANGLER). Can anyone suggest a procedure to isolate
>> and identify the problem?
>> tia dw
Try this.
Backprobe (i.e. don't disconnect) the center pin on the TPS sensor.
Measure the voltage with the ignition on, engine not running.
It should be >200 milliVolts with the throttle closed,
< 4.8 Volts with the throttle wide open,
and butter smooth as you change between the two.
If it jumps it's toast.
If you don't get a good high reading, measure the outer two
wires. Should have 5V on them. (don't short these wires or
you will frag the computer)
--
DougW
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