My 2000 Mazda MPV (1st owner) still running strong, but recently noticed an issue of a high idle with a fully warmed engine.
Symptom: on hot days, or after highway driving with A/C running, when car comes to a stop, it idles high, over 1000 rpm, sometimes reaches 1500 rpm.
Diagnosis: First noticed before summer vacation, happened during vacation driving, not all the time, but most of the time.
1. ECT check: coolant temperature reported normal, around 195 to 200 deg-F for a fully warmed car.
2. Ruled out ECM command (ECM could raise idle speed to charge battery, which suggests either battery or alternator potentially having issues. Alternator was replaced with a Denso ~4 years ago. Battery was new (replaced in Jan 2019)
3. No code, no leak (leak would set lean code).
4. Throttle plate was not sticking, and it rested squarely on the stop screw. TB was cleaned a few years ago.
5. There is enough slack on the throttle cable and the cruise control cable; no kinks on both cables;
6. Working theory settles on IAC (idle air control valve) and TPS (throttle position sensor).
7. Right after driving home from vacation, which has a 450 mile journey of freeway driving, car idles high (~1050 rpm). Put on the scan tool, and live data read TPS at 1.1% without any driver input. Tapped the TPS with a screwdriver, idle went down to 750. This pretty much confirmed that the TPS is acting up when hot.
Mazda does not sell TPS separately, instead they sell the entire throttle body. But you can get Motorcraft TPS which is exactly the same as on the car.
Ford: F5RZ-9B989-BA
Motorcraft: DY-868
Installation: There isn't much room to adjust the sensor. Tile down (connector side) to insert, then rotate back (CCW) to insert screws, then rotate the sensor CW as much as possible. This initially set the TPS reading of 0.3% at CTP (closed throttle). Later during several driving cycles, ECM re-learned, and it always reported 0 at CTP.
1. Disconnect neg battery terminal;
2. Remove water pump belt cover, two 8mm nuts. Unclip the wire/cable holder to remove wire and cable first (cable is for intake runner at high rpms);
3. Remove TPS connector;
4. Remove two screws on TPS sensor
5. Screw torque: 25 in-lbf
Checking: Initial TPS reading was 0.3% at CTP, idling stable at 750 rpm. After a few driving cycles, TPS reads 0 at CTP. Idle is normal.
Mazda does not recommend adjusting the throttle plate stop screw (TAS - throttle adjustment screw): at factory, the amount of flow is measured and set at CTP for ECM programming.
This should apply to MPVs lf later models with the 3.0L engines as well.
BTW, 13 years ago, family took vacation in Maine (Acadia National Park) with the MPV, this year, we returned, with the 19 year old van. All was well.
For reason unknown, I can not post on mpvclub.com, so post here to share with any MPV owners or anyone who still has the Ford Duratec V6 engines.
Symptom: on hot days, or after highway driving with A/C running, when car comes to a stop, it idles high, over 1000 rpm, sometimes reaches 1500 rpm.
Diagnosis: First noticed before summer vacation, happened during vacation driving, not all the time, but most of the time.
1. ECT check: coolant temperature reported normal, around 195 to 200 deg-F for a fully warmed car.
2. Ruled out ECM command (ECM could raise idle speed to charge battery, which suggests either battery or alternator potentially having issues. Alternator was replaced with a Denso ~4 years ago. Battery was new (replaced in Jan 2019)
3. No code, no leak (leak would set lean code).
4. Throttle plate was not sticking, and it rested squarely on the stop screw. TB was cleaned a few years ago.
5. There is enough slack on the throttle cable and the cruise control cable; no kinks on both cables;
6. Working theory settles on IAC (idle air control valve) and TPS (throttle position sensor).
7. Right after driving home from vacation, which has a 450 mile journey of freeway driving, car idles high (~1050 rpm). Put on the scan tool, and live data read TPS at 1.1% without any driver input. Tapped the TPS with a screwdriver, idle went down to 750. This pretty much confirmed that the TPS is acting up when hot.
Mazda does not sell TPS separately, instead they sell the entire throttle body. But you can get Motorcraft TPS which is exactly the same as on the car.
Ford: F5RZ-9B989-BA
Motorcraft: DY-868
Installation: There isn't much room to adjust the sensor. Tile down (connector side) to insert, then rotate back (CCW) to insert screws, then rotate the sensor CW as much as possible. This initially set the TPS reading of 0.3% at CTP (closed throttle). Later during several driving cycles, ECM re-learned, and it always reported 0 at CTP.
1. Disconnect neg battery terminal;
2. Remove water pump belt cover, two 8mm nuts. Unclip the wire/cable holder to remove wire and cable first (cable is for intake runner at high rpms);
3. Remove TPS connector;
4. Remove two screws on TPS sensor
5. Screw torque: 25 in-lbf
Checking: Initial TPS reading was 0.3% at CTP, idling stable at 750 rpm. After a few driving cycles, TPS reads 0 at CTP. Idle is normal.
Mazda does not recommend adjusting the throttle plate stop screw (TAS - throttle adjustment screw): at factory, the amount of flow is measured and set at CTP for ECM programming.
This should apply to MPVs lf later models with the 3.0L engines as well.
BTW, 13 years ago, family took vacation in Maine (Acadia National Park) with the MPV, this year, we returned, with the 19 year old van. All was well.
For reason unknown, I can not post on mpvclub.com, so post here to share with any MPV owners or anyone who still has the Ford Duratec V6 engines.
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