goofy idle anyone got an answer for this?
05-06-10, 08:43 AM
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goofy idle anyone got an answer for this?
okay so i got stuck in traffic on the way home from work and once the car warmed up it was idling at 1500 rpm which it has been doing since i got it but here is where it gets weird from a standstill i would go to pull forward a few feet and if i let the rpm drop below 1000 when pulling forward it would idle at 1000 until i touched the gas. if i didnt get it below the 1000 mark it would idle at 1500 or so. can anyone explain this cause this seems really wierd.
05-06-10, 12:46 PM
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This sounds like problems with the adjustment of the fast idle cam, and maybe the throttle cable. It might also be a bad thermowax.
Check the tension on the throttle cable at the idle position. It should be just slightly slack, no tension. Then push the throttle plates closed. If there is any movement to the stop, the throttle is not closing completely when you release the pedal. Usually this is a throttle cable being not quite slack enough, but it could also be problems with the throttle itself, its spring, etc.
See the FSM for the procedure to adjust the fast idle cam and thermowax. Normally the car should idle at 2500-3000 rpm for 17 seconds (AWS system), then drop to 1500 rpm (if it was a cold start), and then ramp down to 850 rpm once warmed up.
Once at temperature, check to see that the fast idle cam is completely off the roller.
Once you have the throtte cable and fast idle system adjusted, the idle should be 850. If it isnt, jumper the initial set coupler (green, two pin female connector, left front of engine compartment), and set the idle with the set screw on top of the throttle body.
If you run out of travel before getting it down to 850, suspect vacuum leaks, or misadjustment of the idle stop on the main throttle plates. They should be open just a crack at idle; there is a spec in the FSM for how much the gap should be; if it is too much, the idle will be too high.
One more thing to do is check the operation of the BAC valve. You can use an ohmmeter and check it for resistance; put 12v on it and hear it click; and check to see that the idle changes when you pull the electrical connector off the BAC valve.
One more (remote) possibility is the Air Bypass Relay (part of the AWS system). It should close 17 sec after a cold start. If it is not closing completely, it might provide enough bypass air to give you your high idle.
Check the tension on the throttle cable at the idle position. It should be just slightly slack, no tension. Then push the throttle plates closed. If there is any movement to the stop, the throttle is not closing completely when you release the pedal. Usually this is a throttle cable being not quite slack enough, but it could also be problems with the throttle itself, its spring, etc.
See the FSM for the procedure to adjust the fast idle cam and thermowax. Normally the car should idle at 2500-3000 rpm for 17 seconds (AWS system), then drop to 1500 rpm (if it was a cold start), and then ramp down to 850 rpm once warmed up.
Once at temperature, check to see that the fast idle cam is completely off the roller.
Once you have the throtte cable and fast idle system adjusted, the idle should be 850. If it isnt, jumper the initial set coupler (green, two pin female connector, left front of engine compartment), and set the idle with the set screw on top of the throttle body.
If you run out of travel before getting it down to 850, suspect vacuum leaks, or misadjustment of the idle stop on the main throttle plates. They should be open just a crack at idle; there is a spec in the FSM for how much the gap should be; if it is too much, the idle will be too high.
One more thing to do is check the operation of the BAC valve. You can use an ohmmeter and check it for resistance; put 12v on it and hear it click; and check to see that the idle changes when you pull the electrical connector off the BAC valve.
One more (remote) possibility is the Air Bypass Relay (part of the AWS system). It should close 17 sec after a cold start. If it is not closing completely, it might provide enough bypass air to give you your high idle.
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