Is any body having this same problem? Atleast twice a week, for the last 3 months, I find that It always changes!

Whether voltage or resistanced monitored (not that It matters) I can't keep It consistant. Ideas anyone?

 

I'm with ya!

My TPS is always changing, too.

I'll set it to 1.00 (resistance method)
Move it a few times and it'll be at 1.034 etc.

Check it a day later, it'll read .987 or something...

It also varies depending on how hot the car is, and how long I've been driving or it has been sitting.

Luckily I'm running an EMS, and dont' really need the TPS for anything but accel enrichment and decel fuel cut-off....

How much is yours changing?

BTW, using the voltage method, I can't even get 1V. Its always higher...

 

Evil, mine Is within the same specs too. Mind you, I have a brand new TPS, thus ensuring accurate readings. As opposed to say an older one that may not be as accurate.

I don't have to mention that I'm doing this awhile the Motor Is at full operating temperture and beyond, do I?

 

the car has to be 100% hot when you do it. as the thermowax (1500 cold idle thing) opens and closes the TB

if you have the TB mod. you can set it when ever you want and it should remain correct

 

Thats the thing Scott. The Thermowax Is still present. I removed the Secondaries and didn't tamper with the Thermowax or fast Idle Cam. Initially, I assumed It was the Thermowax but wanted to see what else I could come up with before I take the TB off and test It for confirmation.

From wedging In my head to the back of thr Throttle Body, I don't see the pin moving when warm. I spent a good 10 minutes In there looking and listening to brap brap brap...

 

is your thermowax operating correctly?

could it be some thing as simple as a nut or bolt not being tightened up and somehting in there is moving around giving you innacurate readings

some times its a good idea o go in a check all that "other" stuff when you know the part you are working with is good

 

It's safe to say my Thermowax Is cold right now. I'm going to check again and see If the Thermwax expands. If not, I'm going to have to take It off and apply scoulding hot water for confirmation.

 

I did that last time the TB was off. I alternately poured hot and cold water through the hoses and watched the throttle open and close accordingly. Very educational when troubleshooting.

 

I can't say I have a follow up but I plan on taking off the TB and seeing the Thermowax In action.

 

I have the same problem. Everytime ive checked the TPS its been diffrent, so you guys think the thermowax has somthing to do with this?. Could you guys please reiterate.

 

The thermowax won't be causing the TPS to lose adjustment. The problem is you must check it when the engine's fully warmed up.

As the car cools the thermowax opens the throttle, so it you check it when it's not fully warm the reading will be wrong even though the adjustment might still be correct.

So yes, the TPS does have a problem staying correctly set, but it's not because of the thermowax.

 

Don't forget the dashpot, if it's sticking due to being corroded or dirty it can keep the throttle off it's throttle stop. I test drove a t2 once that wouldn decelerate for **** and had a high idle, it was the dashpot being stuck...

personally, i like to just remove all that crap off the throttle body, the thermowax, dash pot, double throttle, all bye bye. Way overcomplicated stock, too many points of failure.

 

First, don't use the voltage method. Use resistance instead. Worlds better, and siginficantly easier.

Second, don't worry about a few hundredths of a volt or ohm. Simple mechanical variation and tolerance in the TPS (it's just a slide-pot) will yeild slightly different readings each time it is measured.

But yes, you want to make sure the car is TOTALLY warmed up prior to checking.