Uneven Idle
#1
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Uneven Idle
Recently my 4Runner has begun idling strangely (see video below). It happens every time the 4Runner is first started and the idle speed begins to lower and usually does not happen again after being driven for about 5+ minutes (although a few times it has happened while waiting at a light after driving for 15+ minutes). No problems when driving (when throttle is open).
I have adjusted the idle to ~800 RPM when in neutral. I have changed the spark plugs and checked most hoses for leaks. The radiator is full.
Any ideas?
http://youtu.be/LSd4lp0otbQ
I have adjusted the idle to ~800 RPM when in neutral. I have changed the spark plugs and checked most hoses for leaks. The radiator is full.
Any ideas?
http://youtu.be/LSd4lp0otbQ
#2
I'm thinking the ECTS or maybe A/C Idle-Up Actuator. But those aren't near the top of the list(A/C Idle-Up isn't even on the list) according to the FSM, which states:
Poor idling/Incorrect first idle:
1. Accelerator Pedal Link
2. Dashpot
3. Throttle Opener
3. Engine Coolant Temperature Sensor(why two #3s? you tell me)
4. Idle Speed Control Valve
5. Engine Control Module
Those just seems to make the most sense to me given the particular set of circumstances. Basically the randomness of it suggests to me that it's electrical in nature. Like the ECTS, the A/C Idle-Up Actuator(if it's got A/C), or possibly the ECM. You should start by checking the higher priority things off the list first though(not sure where to put the A/C Idle-Up on the list). If that's within your abilities. You know where the FSM is, and how to go about finding the appropriate sections and such right?
But, before we get too far ahead of ourselves here, you really need to check for codes as the very first thing you do(if you already haven't). Then if there aren't any, you can move on to mechanically troubleshooting the problem. As the FSM instructs.
Poor idling/Incorrect first idle:
1. Accelerator Pedal Link
2. Dashpot
3. Throttle Opener
3. Engine Coolant Temperature Sensor(why two #3s? you tell me)
4. Idle Speed Control Valve
5. Engine Control Module
Those just seems to make the most sense to me given the particular set of circumstances. Basically the randomness of it suggests to me that it's electrical in nature. Like the ECTS, the A/C Idle-Up Actuator(if it's got A/C), or possibly the ECM. You should start by checking the higher priority things off the list first though(not sure where to put the A/C Idle-Up on the list). If that's within your abilities. You know where the FSM is, and how to go about finding the appropriate sections and such right?
But, before we get too far ahead of ourselves here, you really need to check for codes as the very first thing you do(if you already haven't). Then if there aren't any, you can move on to mechanically troubleshooting the problem. As the FSM instructs.
Last edited by MudHippy; 08-22-2012 at 04:29 PM.
#4
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Join Date: Jul 2006
Location: Utah
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I'm thinking the ECTS or maybe A/C Idle-Up Actuator. But those aren't near the top of the list(A/C Idle-Up isn't even on the list) according to the FSM, which states:
Poor idling/Incorrect first idle:
1. Accelerator Pedal Link
2. Dashpot
3. Throttle Opener
3. Engine Coolant Temperature Sensor(why two #3s? you tell me)
4. Idle Speed Control Valve
5. Engine Control Module
Those just seems to make the most sense to me given the particular set of circumstances. Basically the randomness of it suggests to me that it's electrical in nature. Like the ECTS, the A/C Idle-Up Actuator(if it's got A/C), or possibly the ECM. You should start by checking the higher priority things off the list first though(not sure where to put the A/C Idle-Up on the list). If that's within your abilities. You know where the FSM is, and how to go about finding the appropriate sections and such right?
But, before we get too far ahead of ourselves here, you really need to check for codes as the very first thing you do(if you already haven't). Then if there aren't any, you can move on to mechanically troubleshooting the problem. As the FSM instructs.
Poor idling/Incorrect first idle:
1. Accelerator Pedal Link
2. Dashpot
3. Throttle Opener
3. Engine Coolant Temperature Sensor(why two #3s? you tell me)
4. Idle Speed Control Valve
5. Engine Control Module
Those just seems to make the most sense to me given the particular set of circumstances. Basically the randomness of it suggests to me that it's electrical in nature. Like the ECTS, the A/C Idle-Up Actuator(if it's got A/C), or possibly the ECM. You should start by checking the higher priority things off the list first though(not sure where to put the A/C Idle-Up on the list). If that's within your abilities. You know where the FSM is, and how to go about finding the appropriate sections and such right?
But, before we get too far ahead of ourselves here, you really need to check for codes as the very first thing you do(if you already haven't). Then if there aren't any, you can move on to mechanically troubleshooting the problem. As the FSM instructs.
Thanks for the helpful information. I do have an electronic copy of the FSM. I will check for codes and if there are none, start on the list.
Thanks again.
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