throttle postion sensor test
07-09-2007, 10:41 PM
#2
Drifting
WSM Volume 1A, page 28-60 states "approximately 1 degree" throttle for idle enrichment, and 2/3 throttle for full load enrichment.
I set my 90' S4 as described in this thread, post #14:
https://rennlist.com/forums/showthre...t=GTS+kickdown
I set my 90' S4 as described in this thread, post #14:
https://rennlist.com/forums/showthre...t=GTS+kickdown
07-10-2007, 01:13 AM
#3
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The 928 is not a typical TPS. It is not a linear output variable resistor.
It is actually just a case containing 2 switches.
One is the Idle position sensor. It is a self-contained micro-switch that you can hear "click" when triggered just off idle, and at the idle stop.
The other is an opened spring-contact switch inside the case that rides a cam on the TPS shaft. The cam closes the contacts at approcimatel 2/3 throttle. This switch feeds the LH unit (fuel injection brain) ionformation that the engine is in "power-making" mode and triggers the LH to go open-loop.
This is, to go to the preprogrammed air-fuel map that will run the engine at approximately 12.5/1 A/F rather than the 14/1 ratio in closed loop off of the o2 sensor.
This is why the test proceedure is not a resistance or a voltage measurement check.
It is actually just a case containing 2 switches.
One is the Idle position sensor. It is a self-contained micro-switch that you can hear "click" when triggered just off idle, and at the idle stop.
The other is an opened spring-contact switch inside the case that rides a cam on the TPS shaft. The cam closes the contacts at approcimatel 2/3 throttle. This switch feeds the LH unit (fuel injection brain) ionformation that the engine is in "power-making" mode and triggers the LH to go open-loop.
This is, to go to the preprogrammed air-fuel map that will run the engine at approximately 12.5/1 A/F rather than the 14/1 ratio in closed loop off of the o2 sensor.
This is why the test proceedure is not a resistance or a voltage measurement check.
07-10-2007, 01:23 AM
#5
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A quick check for if the full throttle switch is working on the '85-'86 is found in the connector at the front of the engine. It's the same circuit as the idle set terminals. B will go to ground (C) when the throttle switch is tripped.
_C_
B_A
_C_
B_A
