3.4L TPS not registering 100% throttle
#1
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3.4L TPS not registering 100% throttle
Hi guys,
I hooked up my OBD II scanner the other day to my new-to-me '97 4Runner Limited with the 3.4 to check the readings of the engine's sensors. With the engine off and ignition on, I noticed that the TPS was registering a value of 11.8% with my foot completely off the gas. When I depressed the gas pedal all the way, it registered 76.5%. I opened the throttle body all the way by hand and it still returned a value of 76.5%. This doesn't seem right to me; do I need a new TPS?
I hooked up my OBD II scanner the other day to my new-to-me '97 4Runner Limited with the 3.4 to check the readings of the engine's sensors. With the engine off and ignition on, I noticed that the TPS was registering a value of 11.8% with my foot completely off the gas. When I depressed the gas pedal all the way, it registered 76.5%. I opened the throttle body all the way by hand and it still returned a value of 76.5%. This doesn't seem right to me; do I need a new TPS?
#4
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Location: Outer Banks, NC
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With my scangauge ii, it reads 10 at 700 RPMs.
Are you getting a code indicating that the TPS is problematic? If not, don't sweat it.
If you want to check it though:
http://www.ncttora.com/fsm/
Are you getting a code indicating that the TPS is problematic? If not, don't sweat it.
If you want to check it though:
http://www.ncttora.com/fsm/
#5
Registered User
Per my '99 FSM, p. DI-169:
Throttle valve fully closed: 7-11%
Throttle valve fully open: 65-75%.
You are high on both by a smidgin. The FSM goes on to say:
The values given below for "Normal Condition" are representative values, so a vehicle may still be normal even if its value varies from those listed here. So do not decide whether a part is faulty or not solely according to the "Normal Condition"here.
EDIT: See page DI-11 here: http://www.ncttora.com/fsm/1996/SIL/...zfe/preche.pdf
Note: All these specs are the same in '99, except that there are no #2 fuel trim items in '99.
Last edited by TheDurk; 06-24-2011 at 11:24 AM.
#6
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Hmmmm... I don't really understand why it would be "normal" for the TPS to register a value ~25% less than what the driver is asking for. But if that's the way it's supposed to be then I won't worry about it.
#7
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Beats me, too. That TPS is used on other engines as well so maybe one of those has different geometry that allows for a wider angle of arc on the butterfly. It's also more precise to keep a resistance type sender a bit within its extreme range. But I'm sure the ECM is designed so that it regards anything 65%+ as WOT. In any case, the butterfly is what counts as far as volume of fuel/air mixture, the TPS just affects fuel trim and ignition timing. Those probably hit their extreme values somewhere before WOT, like maybe 50%+ (just going by how old-time mechanical distributor advances work).
Last edited by TheDurk; 06-25-2011 at 06:27 AM.
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#8
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So strange to see TPS issues, all of a sudden at the same time mine is having issues. I've changed my TPS and I still get no acceralation..wish mine would get resolved i'm not enjoying my Runner right now. 235k and this is the only thing to ever go wrong.
#9
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your tps will never read 100% or 0% because it uses those values for diagnostic purposes. and it associates those percentages with voltages, so if it sees a certain voltage(percentage), the ecm knows that there is a problem
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