TPS Volts - LT1
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Joined: Jun 2007
Posts: 52
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From: Germantown WI
TPS Volts - LT1
Hi,
1995 LT1.
I measured my TPS % and volts tonight viaq TTS DataMaster and found:
Low
.65 volts; 0.00%
High
3.39 volts; 84.3% (gas pedal to the floor)
I know this is not correct. I would like to know what to do to fix it. Adjust? Replace?
Thanks,
Ron
1995 LT1.
I measured my TPS % and volts tonight viaq TTS DataMaster and found:
Low
.65 volts; 0.00%
High
3.39 volts; 84.3% (gas pedal to the floor)
I know this is not correct. I would like to know what to do to fix it. Adjust? Replace?
Thanks,
Ron
Melting Slicks
Joined: Dec 2000
Posts: 2,719
Likes: 59
From: Fremont Oh
If I recall the TPS is "self centering".. I know on the 96's there is no adjustment.
You can key on ( with the engine off) and take the readings again at 100% you should be just shy of 5 volts...
Mo
You can key on ( with the engine off) and take the readings again at 100% you should be just shy of 5 volts...
Mo
Pro
Joined: Aug 2009
Posts: 725
Likes: 4
From: Plano, TX
Check to make sure your throttle is opening all the way. Have someone press the pedal to the floor while you look in the throttle body. It is probably a matter of adjusting throttle linkage so it opens all the way.
Burning Brakes
Joined: Feb 2009
Posts: 785
Likes: 3
From: Richmond Virginia
If you've checked visually and the throttle blades are in fact in the WOT position--then remove the connector at the TPS-- jumper the grey and the blue wire together--turn key on--scan tool should show 4.5 to 5.0 volts--if you have this reading--then TPS is faulty.
Le Mans Master
Joined: Aug 2004
Posts: 5,141
Likes: 7
From: Metairie Louisiana
Check the throttle linkage comming from the ASR. There is an adjustment button on it. It's fairly common for older C4's to need some adjustment. Sometimes mine would read less then 100% in TTS also. I could always tell it needed to be adjusted becuase I would lose major pickup at WOT and my trans would not downshift. I think my cable may need replacement however they dont make these anymore and I havent been able to find a correct replacement. I havent had any trouble with it in a long time though and I just did a couple of data logs the other day.
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
Either Datamaster is no reading it correctly or the TPS could be bad,or it is not open 100%. If you have never measured this before and have no base line for this measurement, then I would measure it manually with a DVM.
I use a long pin that goes up alongside the wire to make contact for the measurement You can also use a strait pin and puncture the wire. What you're looking for is to make sure one end is at ground potential measuring 0.00 volts. The high side should measure 5.0 volts (from the PCM), and then you can read the wiper voltage directly as you open and close the throttle.
Just for FYI, I measured mine using a Tech1 and got 0.64 closed and 4.14 volts at 100% open. Yours may be slightly different. I did measure the voltage with a meter but it's been so long I don’t remember what the exact voltages was.
I got the same voltage at 85% that you did. Maybe the throttle is not open all the way.
I use a long pin that goes up alongside the wire to make contact for the measurement You can also use a strait pin and puncture the wire. What you're looking for is to make sure one end is at ground potential measuring 0.00 volts. The high side should measure 5.0 volts (from the PCM), and then you can read the wiper voltage directly as you open and close the throttle.
Just for FYI, I measured mine using a Tech1 and got 0.64 closed and 4.14 volts at 100% open. Yours may be slightly different. I did measure the voltage with a meter but it's been so long I don’t remember what the exact voltages was.
I got the same voltage at 85% that you did. Maybe the throttle is not open all the way.
Pro
Joined: Dec 2009
Posts: 502
Likes: 0
Check the throttle linkage comming from the ASR. There is an adjustment button on it. It's fairly common for older C4's to need some adjustment. Sometimes mine would read less then 100% in TTS also. I could always tell it needed to be adjusted becuase I would lose major pickup at WOT and my trans would not downshift. I think my cable may need replacement however they dont make these anymore and I havent been able to find a correct replacement. I havent had any trouble with it in a long time though and I just did a couple of data logs the other day.
