TPS Sensor slotted
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
Likes: 5
From: Sandhills of North Carolina
TPS Sensor slotted
I slotted the screw holes on my TPS a while back. Was this a mistake? Would it be better to get another one and just tighten up the screws and let the PCM set the voltage?
Last edited by Weav's Vet; Jul 25, 2010 at 10:42 AM.
Racer
Joined: May 2005
Posts: 497
Likes: 1
From: Casa Grande Az
People do that so they can set their TPS voltage exactly where the FSM suggests. Some of the cheapo TPS sensors that you buy now adays are sometimes off a good bit.
Now wether the PCM compensates or even cares about this, I don't know.
I slotted mine and have had no issues with anything.
Now wether the PCM compensates or even cares about this, I don't know.
I slotted mine and have had no issues with anything.
Melting Slicks
Joined: Feb 2006
Posts: 2,753
Likes: 15
From: backwoods upstate ny
89 and prior need slots to set tps....90 and newer the ecm reads 'whatever' the TPS value is at start-up (within certain limits hi/lo) and resets from that as 0 throttle...if you use a late tPi throttlebody or an LT1 t-body on a 89/earlier ecm controlled vehicle the TPS screw holes will need to be modded into slots and TPS adjusted to proper voltage...doubt that Weav made slots long enuf to exceed the late ecm reset range, but check SM for acceptable max/min voltage and verify it is OK (ecm may display MIL if base voltage is 'out range', maybe not)
Last edited by redrose; Jul 25, 2010 at 02:42 PM.
Pro
Joined: May 2006
Posts: 637
Likes: 0
In my 91 FSM it is written that the ECM will look for a reading between 0.3 to 0.9 volts at startup.
Dunno if that is the same on later models, but it´s fairly easy to check the reading on those with a multimeter.
If the connector is vertical as on my 91, it´s the two wires from the top you are dealing with.
Don´t disconnect the terminal, you have to try to pry in with two tiny needles, and fasten the multimeter leads with some loose alligator clips.
Ignition on, no start, read voltage between those two, if neccesary, adjust by loosening the torxes and try to turn the TPS a little.
You´ll see where you get, if you think you have it arround 0.54-0.65 volts, fasten the torxes, and check again if it´s still the right value.
Then you open the throttle to WOT, to check if you have 4.5-4.8 volts.
Done...
I think...
Dunno if that is the same on later models, but it´s fairly easy to check the reading on those with a multimeter.
If the connector is vertical as on my 91, it´s the two wires from the top you are dealing with.
Don´t disconnect the terminal, you have to try to pry in with two tiny needles, and fasten the multimeter leads with some loose alligator clips.
Ignition on, no start, read voltage between those two, if neccesary, adjust by loosening the torxes and try to turn the TPS a little.
You´ll see where you get, if you think you have it arround 0.54-0.65 volts, fasten the torxes, and check again if it´s still the right value.
Then you open the throttle to WOT, to check if you have 4.5-4.8 volts.
Done...
I think...
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
Likes: 5
From: Sandhills of North Carolina
89 and prior need slots to set tps....90 and newer the ecm reads 'whatever' the TPS value is at start-up (within certain limits hi/lo) and resets from that as 0 throttle...if you use a late tPi throttlebody or an LT1 t-body on a 89/earlier ecm controlled vehicle the TPS screw holes will need to be modded into slots and TPS adjusted to proper voltage...doubt that Weav made slots long enuf to exceed the late ecm reset range, but check SM for acceptable max/min voltage and verify it is OK (ecm may display MIL if base voltage is 'out range', maybe not)
