(12-14-2017 07:03 PM)max Wrote: tps overall resistance; 6.25 k ohm ( yellow/black )
throttle lower position; 1.095 k ohm ( red/black )
throttle high position ; 6.05 k ohm
( all measured ref to " ground or lower section ie green/black" and tps disconnected from ecu.
Voltages;
yellow/black +4.97 volt
red/black idle 0.482 volt wot 4.45 volt
green/black 0 volt ( the black meter probe )
Voltage increases in a linear way from lower to higher position.
Max: Major kudos to you for the set-up, testing and video recording!
How does the FSM spec of sensor resistance between black/red and black/green of 0.5 to 1.5 K ohms correlate to your readings?
The 1/2 volt to 4 1/2 volt range seems very typical.
Very important is the linear change as the throttle position changes...no bumps or hiccups.
(12-14-2017 07:03 PM)max Wrote: ...on startup the iacv opens 65 steps and then closes 12 steps with a cold engine and 35 wiith a warm engine.
This happens in the blink of an eye as demonstrated at the very end of the video so i slowed it down to count the steps and direction, open and close.
the ecu does not know what position the iacv is at startup , so it always commands the valve open with 65 pulses, it then makes a decision to close x many steps based on the temperature of the eot sensor.
Condensation for a future write-up:
A. IACV opens 65 pulses when ignition on and stop/run in run
B. Cold (any specific ambient range?) IACV then closes 12 pulses for a net opening of 53 pulses.
C. Warm IACV then closes 35 pulses for a net open of 30 pulses.
Questions (for which we may not have data):
1. How many pulses (stepper motor steps) per revolution?
2. How many pulses per linear distance?
3. When stop/run is stopped, does IACV motor close plunger?
4. If so does it fully close?
This certainly provides a very smooth warm-up operation, especially compared to steps on carburetor linkage. It finally got cool enough in Las Vegas valley last week for my 2014 standard to fast idle at 1500 RPMs instead of 1300.
Your information should help all of us better understand IACV operation.
a. Increased air supply increases idle speed and lends to the understanding of why a minor intake vacuum leak would cause increased idle speed.
b. Cycling the stop/run commands the IACV to preposition by open/close movement, which offers one of two (IACV or TPS) likely explanations for Riko's restart in his video.
For basic info on stepper motors, this video explains how it steps:
https://www.youtube.com/watch?v=zK1Y1O7XZes
This is a more sophisticated motor in comparison to the Superior Slo-Syn motors that I sold beginning in 1984.
A stepper is frequently connected to a lead screw to transfer rotary motion to linear motion. Therefore linear travel, in relation to pulses, would be a function of (a) pulses per revolution and (b) screw pitch.