Effect Out of Spec TPS Voltage?

Sep 30, 2005
I've had my 87 GN for about 1 week now, I'm a 1st time TR owner but have been reading this board and others for years.

Scanmaster 2.0 shows idle TPS to be 0.42V and 4.1V at WOT. I will adjust this to get it within spec at WOT but was wondering what effect a low voltage reading at WOT would cause. I assume the TPS is referenced for ignition and fuel injection events and may not be operating to full potential with a low TPS value? Also, I believe I've read that the Scanmaster starts recording at 4.3V from the TPS, but I can recall O2 mV and KR when I'm only getting 4.1V at WOT.

On a side note I am very excited about this car and can't wait to learn as much as possible!:D
car wont go into inrichement mode and can cause a lean effect. very bad things can start happening.
Aftermarket boost gauge shows 10 psi, 02 voltage is ~.800 w/ 0 KR. Looks like I am safe with the current settings. I should definately set the TPS before increasing boost though?
you need to have the tps set correct no matter what. also i would invest in a Wideband. tunning with 02's is hard.

Your readings are nothing to worry about..

The scanmaster starts recording at 3.0V and above
PE occurs at 3.75V and 4.0v is the trigger for ac compressor shut off
From what I've read PE is activated based on load and how fast the TPS increases. I could be wrong though. I know I've seen PE just from tapping the gas fast enough. The only other thing that will be affected is you may not get WOT timing and fuel. Which at 10psi, may not be a big deal, but above that could cause problems. What chip do you run? WOT TPS voltage can vary from chip maker to chip maker. I want to say stock is above 4.4~4.5v while a TT chip from Eric is a bit lower (I think) making it easier to adjust the TPS. Trick is to pull on the TPS towards the front of the car while adjusting it. HTH.