ECT Power stall in Drive
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Joined: Feb 2020
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From: CA
ECT Power stall in Drive
Hello all,
93 SC400 138k. Most maintenance has been completed and up to date, ECU has been rebuilt. I'm having an intermittent issue with idling in ECT Power only. I noticed about 6 months ago I stalled out in ECT Power below 40mph, had enough power to pull into a side street turned the key and it started right up, no issues continued my trip, but idle was slightly low so I held the gas a bit to settle the idle. A few days ago, it rained, and I drove the car to work, since my truck is having some issues, getting there was fine, later in the day I went to lunch and had 2 failed starts, once I got it to start, I had an extremely low idle. The idle was at the very bottom line of the tach. Since I'm leaving the ECT Power on all the time now, I turned off and the idle climbed to the normal area, which is around the 3rd line (Assuming 700RPM) below 1K RPM. I go to work pre-dawn and it turns right on all the time, just these last 3 days, I've been stalling while driving. 1st day stalled in the parking lot, 2nd day stalled on the highway in traffic but was close enough to the emergency lane to pull over, yesterday stalled out while making a left-hand turn had enough power to pull in the parking lot and park. I've been intermittently turning the ECT Power on and off based on the idling perspective, but today on ECT Power I noticed the idle started bouncing, very little similar to when your analog watch's battery dies, and the seconds hand just bounces up and down. More like 20RPMs, very slight variation, don't think I've seen this before, and am usually paying attention to the idle since I've had issues before. I was wondering if anyone else has had a similar issue and can guide me through this. I'll edit this post and add pictures on a break.
93 SC400 138k. Most maintenance has been completed and up to date, ECU has been rebuilt. I'm having an intermittent issue with idling in ECT Power only. I noticed about 6 months ago I stalled out in ECT Power below 40mph, had enough power to pull into a side street turned the key and it started right up, no issues continued my trip, but idle was slightly low so I held the gas a bit to settle the idle. A few days ago, it rained, and I drove the car to work, since my truck is having some issues, getting there was fine, later in the day I went to lunch and had 2 failed starts, once I got it to start, I had an extremely low idle. The idle was at the very bottom line of the tach. Since I'm leaving the ECT Power on all the time now, I turned off and the idle climbed to the normal area, which is around the 3rd line (Assuming 700RPM) below 1K RPM. I go to work pre-dawn and it turns right on all the time, just these last 3 days, I've been stalling while driving. 1st day stalled in the parking lot, 2nd day stalled on the highway in traffic but was close enough to the emergency lane to pull over, yesterday stalled out while making a left-hand turn had enough power to pull in the parking lot and park. I've been intermittently turning the ECT Power on and off based on the idling perspective, but today on ECT Power I noticed the idle started bouncing, very little similar to when your analog watch's battery dies, and the seconds hand just bounces up and down. More like 20RPMs, very slight variation, don't think I've seen this before, and am usually paying attention to the idle since I've had issues before. I was wondering if anyone else has had a similar issue and can guide me through this. I'll edit this post and add pictures on a break.
I've been leaving mine in ECT Power mode all the time lately, too, and haven't experienced anything of the sort. Mine is a different system, of course, being vvt.
Since yours isn't doing it in Normal mode, that would seem to rule out the TPS and IACV. So, recalibrating them for Power mode's idle would probably mess up their behavior in other driving conditions. The transmission itself shouldn't have any effect on idle, so all that seems to leave is the ECU misbehaving. Did you have it serviced by someone you can follow up with to see if it needs another look?
Since yours isn't doing it in Normal mode, that would seem to rule out the TPS and IACV. So, recalibrating them for Power mode's idle would probably mess up their behavior in other driving conditions. The transmission itself shouldn't have any effect on idle, so all that seems to leave is the ECU misbehaving. Did you have it serviced by someone you can follow up with to see if it needs another look?
Thread Starter
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Joined: Feb 2020
Posts: 662
Likes: 156
From: CA
I've been leaving mine in ECT Power mode all the time lately, too, and haven't experienced anything of the sort. Mine is a different system, of course, being vvt.
Since yours isn't doing it in Normal mode, that would seem to rule out the TPS and IACV. So, recalibrating them for Power mode's idle would probably mess up their behavior in other driving conditions. The transmission itself shouldn't have any effect on idle, so all that seems to leave is the ECU misbehaving. Did you have it serviced by someone you can follow up with to see if it needs another look?
Since yours isn't doing it in Normal mode, that would seem to rule out the TPS and IACV. So, recalibrating them for Power mode's idle would probably mess up their behavior in other driving conditions. The transmission itself shouldn't have any effect on idle, so all that seems to leave is the ECU misbehaving. Did you have it serviced by someone you can follow up with to see if it needs another look?
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