I've got a LX470 with 322K miles. It's recently started intermittently loosing power, typically, when towing my 5500lb travel trailer uphill. This only happens very intermittently (and momentarily) and no check-engine light is displayed (no codes are logged). Engine never completely dies. I can closely "simulate" this intermittent condition by briefly lifting and re-pressing gas pedal when climbing a hill. I think I've ruled out transmission issue as the failure occurs in both 2nd gear and 3rd gear (D) both with and without overdrive enabled. (shifts are smooth and the RPMs briefly drop on failure). On a recent trip, I performed a number of 'road-side' repairs basically shot-gunning possible causes and now considering possibly replacing the complete Throttle Body (including Throttle/Accelerator position sensors). It seems like this is a good time to find if there are any real-time analysis tool which could help root cause? I purchased the ANCEL TD700 OBD 2 tool, but disappointed to find it does not provide real-time TPS or ignition timing info for the 2000 model year. Most recent 'shot-gun' fix was replacing the knock sensors, as I saw a Tundra forum post with exactly same symptoms. (in that case, knock sensor(s) were intermittently tripping causing timing setbacks).
I'm running out of ideas and appreciate any suggestions!
Update: After updating Firmware on the TD700, I see live data-stream options for 'ignition timing advance for #1 cylinder' and also 'Absolute Throttle Position'. Will try to capture some DataStream information on failure.
Within the last year:
1) New timing belt and all wear components
2) New Spark Plugs
3) new steering rack and heater T's
more recently in shot-gunning this issue I've:
1) replaced MAF sensor
2) replaced fuel-pump and filters
3) cleaned throttle body
4) fuel injector cleaner
5) octane boost (when on the road towing) did not seem to reduce the failure rate.
6) replaced knock sensors
Possible next steps:
0) capture Datasteam data on failure.
1) replace throttle body?
2) motor mounts? could knock sensors be retarding timing due to engine shake?
3) take to dealer for debug???
I'm running out of ideas and appreciate any suggestions!
Update: After updating Firmware on the TD700, I see live data-stream options for 'ignition timing advance for #1 cylinder' and also 'Absolute Throttle Position'. Will try to capture some DataStream information on failure.
Within the last year:
1) New timing belt and all wear components
2) New Spark Plugs
3) new steering rack and heater T's
more recently in shot-gunning this issue I've:
1) replaced MAF sensor
2) replaced fuel-pump and filters
3) cleaned throttle body
4) fuel injector cleaner
5) octane boost (when on the road towing) did not seem to reduce the failure rate.
6) replaced knock sensors
Possible next steps:
0) capture Datasteam data on failure.
1) replace throttle body?
2) motor mounts? could knock sensors be retarding timing due to engine shake?
3) take to dealer for debug???
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