[svxistentialist]

Originally Posted by redlightningsvx

Ok, briging this up because of recent sucky slowness action at the drag strip. I adjusted the tps to .48 volts an the idle is set 1 tick below 1000rpms. Then when the fans kick on the tps reads .401-3 volts, and when the fans quit running it goes back to .48 volts. Just want to know if this is normal. Also i'm getting a code 31 for the tps and it will not clear.

Hi Seth

We'll have to get Trevor back soon to give us the definitive answer to these questions.

I'll venture my opinion for what it is worth:

First and foremost you are supposed to set this voltage value with the ignition on, and it's fair to presume that this means just the ignition and no ancillaries. In that respect you may be the first to notice these differences with the fans.

Do you mean the engine cooling fans? I presume so, they would be a heavy draw. This may mean you are adjusting the TPS after a drive while the engine is hot. I would advise adjusting it on a cold engine with nothing running nor switched on except the ignition. Not having checked this out for myself I don't know for certain, but I would expect the voltage drop you noted is normal when the fans are drawing. Remember with only the ignition switched on, you are drawing directly from the battery, which is a finite source. The alternator is not pumping up the system as it will when the engine is running.

Regards your code 31 you should possibly run the second TPS test in the How-Tos, the one from SVX _Commuter.

What goes wrong with an old TPS can be the position where the internal wiper arm normally sits while you are driving [say you drive at 2200 RPM for the sake of argument] this portion of the slider wears at that position. The voltage is meant to change smoooooothly as Trevor says over the range of the device. If voltage jumps or changes momentarily to zero at the worn position, this will throw the TPS code. There is no fix for this that we know of except replace it with a new one.

Joe