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throttle position sensor replacement by Bruce
Started on: 11-21-2012 09:39 PM
Replies: 19 (673 views)
Last post by: notaguru on 12-22-2013 11:59 PM
Bruce
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11-21-2012 09:39 PM Click Here to See the Profile for BruceClick Here to Email BruceSend a Private Message to BruceEdit/Delete MessageReply w/QuoteDirect Link to This Post

As I look at the Chilton instructions,then I look at the throttle body of the V6, it appears that the TPS just unscrews with the two torx screws holding it in place. Am I looking in the right place, that is, opposite the throttle cable, opposite the firewall manifold? It looks pretty easy to replace, unless I'm either looking at the wrong part or overly optimistic.

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thedrue
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11-21-2012 10:36 PM Click Here to See the Profile for thedrueSend a Private Message to thedrueEdit/Delete MessageReply w/QuoteDirect Link to This Post

Sounds like you are spot on. Very easy part to replace. Just the two screws and the 4 wire connector.

Good luck!

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phonedawgz
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11-22-2012 02:36 AM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post

3 wire connector - Gray, Dk. Blue, Black

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mcguiver3
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11-22-2012 01:25 PM Click Here to See the Profile for mcguiver3Send a Private Message to mcguiver3Edit/Delete MessageReply w/QuoteDirect Link to This Post

That's the baby.
The thing with the TPS is it may need adjustment.
You need a scanner and set the voltage to .5 + - at idle.
I think that's the value.

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Bruce
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11-29-2012 12:12 PM Click Here to See the Profile for BruceClick Here to Email BruceSend a Private Message to BruceEdit/Delete MessageReply w/QuoteDirect Link to This Post

The instructions I received with the TPS indicate that I have to remove the throttle body, etc., etc. Is all this necessary, or can I just do as I read here, and remove and replace the TPS by itself?
Thanks,
bb

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fierofool
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11-29-2012 01:15 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageClick Here to Email fierofoolSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post

Just remove the connector and the 2 screws, swap out the sensor and reinstall the screws with the metal bridge hold down and plug it back in. I've changed out a couple and never adjusted them. Actually, I didn't know you could adjust them. I have 3 of them before me and there are no adjustment screws of any kind. Pray tell, how do you adjust it?

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Rattman
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11-29-2012 02:14 PM Click Here to See the Profile for RattmanClick Here to visit Rattman's HomePageClick Here to Email RattmanSend a Private Message to RattmanEdit/Delete MessageReply w/QuoteDirect Link to This Post

I just did mine its not bad to do. Just be careful not to break the bolts that hold it in...they have been in there a while

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Pyrthian
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11-29-2012 02:45 PM Click Here to See the Profile for PyrthianClick Here to Email PyrthianSend a Private Message to PyrthianEdit/Delete MessageReply w/QuoteDirect Link to This Post

the holes are slightly slotted, so adjustment is possible - but rarely necessary.
you will need to drive around for a bit, for the ECM to re-calibrate.

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mcguiver3
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11-29-2012 04:13 PM Click Here to See the Profile for mcguiver3Send a Private Message to mcguiver3Edit/Delete MessageReply w/QuoteDirect Link to This Post

Some of the TPS have slotted holes some don't.
To adjust all you need is a needle nose pliers and
bend the tab a little until you get the .5 volts.

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Bruce
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11-29-2012 05:26 PM Click Here to See the Profile for BruceClick Here to Email BruceSend a Private Message to BruceEdit/Delete MessageReply w/QuoteDirect Link to This Post

Done...we shall see.
Thanks for all the help!
bb

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Bruce
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12-03-2012 06:06 PM Click Here to See the Profile for BruceClick Here to Email BruceSend a Private Message to BruceEdit/Delete MessageReply w/QuoteDirect Link to This Post

Runs a little better, but still stutters at the beginning of each shift and at cruising speed, although not too bad at the latter.
The TPS went on without any problems, so that's a plus for my temperment.
bb

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phonedawgz
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12-03-2012 09:07 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post

Motor Mounts. They aren't expensive. Not a huge job but more than a TPS to replace. Replace all three.

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Bruce
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12-03-2012 09:24 PM Click Here to See the Profile for BruceClick Here to Email BruceSend a Private Message to BruceEdit/Delete MessageReply w/QuoteDirect Link to This Post

How would motor mounts affect acceleration?
Incidentally, all motor mounts were replaced about 15,000 miles ago. They shouldn't fail that quickly, should they?
Thanks!
bb

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phonedawgz
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12-03-2012 09:45 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post

Well if they were just replaced, and if what you are having is a studder, not a shudder, the I will retract my 'engine mounts' statement

No SES light?

The SES light does work right?

Any access to either a fuel pressure gauge or an ECM scanner?

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Bruce
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12-03-2012 10:45 PM Click Here to See the Profile for BruceClick Here to Email BruceSend a Private Message to BruceEdit/Delete MessageReply w/QuoteDirect Link to This Post

PD,
I'm going to take it into a diagnostic expert nearby, since I've done everything that is within my reach. I don't want to go in uncharted territory and really screw something else.
I wrote another entry entitled "what else can I possibly do," or something to that effect, in which I document everything I've tried / replaced to date (idle air control valve, mass air flow, mass air temperature sensor, ) O2 sensor, fuel injectors, fuel pump (though I'm beginning to doubt the quality of the replacement), s sensor,spark plugs and wires, cap and rotor, Cardone remanufactured distributor; cleaned throttle body; throttle position sensor, air temp sensor, coolant temperture sensor, and ignition control module. My neighbor checked the ignition coil, and I'm taking his word that it tested ok
The catalytic converter is only 15,000 miles old and was a stainless steel product I purchased from Summit, The muffler is a Flowmaster from WCF. Hopefully these two items live up to their hype.
I'm thinking it must be some kind of fuel flow problem, since the stuttering occurs to greater and lesser degrees at every part of shifting and acceleration. Or it may be a vacuum leak, but I don't want to blow myself to eternity to find one (vacuum leak, that is).
It's been very educational in my quest to find the problem, particularly since I am not much of a mechanic. I'll leave the intricate stuff to the very well regarded mechanic with whom I've made an appointment.
Thanks, though, for all your help. You have always responded quickly and with great advice to my previous questions.

Best regards,
Bruce

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34blazer660
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12-03-2012 11:28 PM Click Here to See the Profile for 34blazer660Click Here to Email 34blazer660Send a Private Message to 34blazer660Edit/Delete MessageReply w/QuoteDirect Link to This Post

if you replaced the TPS, the voltage must be checked and adjusted within tolerance. the ECM calibrates at KEY ON and uses the base reference voltage as 0% TPS, unless the voltage at idle is over, iirc ~.530V. a voltmeter or scanner will help verify TPS voltage, if voltage is over ~.530V the engine will have trouble starting and part throttle hesistation, do to the ecm thinking theres an OFF IDLE condition

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Bruce
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01-17-2013 09:37 PM Click Here to See the Profile for BruceClick Here to Email BruceSend a Private Message to BruceEdit/Delete MessageReply w/QuoteDirect Link to This Post

It's been a while since I posted this, but I installed the TPS without doing any of the calibration. The car runs great (especially after I replaced 2 AC Delco spark plugs that had cracked ceramic insulators). Should I still have the TPS calibrated to be on the safe side, or should I leave it as it is.
Thanks, and Happy New Year!
bb

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mcguiver3
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01-18-2013 07:22 PM Click Here to See the Profile for mcguiver3Send a Private Message to mcguiver3Edit/Delete MessageReply w/QuoteDirect Link to This Post

If it's starting and running OK you could leave it but it would be nice to know what the value actually is.
.5 volts at idle is the place to be.

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Bruce
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01-18-2013 08:36 PM Click Here to See the Profile for BruceClick Here to Email BruceSend a Private Message to BruceEdit/Delete MessageReply w/QuoteDirect Link to This Post

I'm taking in on Wednesday to have the harmonic balancer replaced, so I'll have the TPS voltage checked then.
Thanks for responding!
bb

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notaguru
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12-22-2013 11:59 PM Click Here to See the Profile for notaguruClick Here to Email notaguruSend a Private Message to notaguruEdit/Delete MessageReply w/QuoteDirect Link to This Post

If the TPS is just a potentiometer, calibration may not need a scanner or an OBD-1 connection. We should be able to measure voltages with pins and a common Digital VoltMeter (DVM) - like the perpetual freebie from Harbor Freight. Depending upon the wiring, you may have to trim away some insulation to access the wires. Stick a pin into the center (where the internal copper is) in each of the three wires. There should be a stable voltage (5? 12?) between two of them, then 0.5V between ground and the one that's connected to the potentiometer's wiper. You can't go wrong, because the voltage to the other connection will be many times greater.


GROUND --->VVVVVVVVVVVVVVVVVVVVV<--- +V
----------- ^

0.5V


As commented, if the torx screws pass through slotted holes, adjusting should be a snap - just slight rotation. I looked at one photo of a Fiero TPS and saw only round holes, so perhaps there's zero or little adjustment room.

Will that work?

If you're a bit paranoid, almost any glue or sealant will restore the wire's insulation.

[This message has been edited by notaguru (edited 12-24-2013).]

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