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Discussion Starter · #1 ·
I set my TPS voltage to 0.97, after a while when the car warms up it goes to 0.99

Is this normal ??!!
 

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It doesn't take much to change the voltage. So long as its under 1 volt.Its possibly idling faster and your altinator is charging slghtly more..
 

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HAITHAM said:
I set my TPS voltage to 0.97, after a while when the car warms up it goes to 0.99

Is this normal ??!!
It happens. I've seen my TPS voltage shift upwards with heat first hand.
Just set it to ~.93 to be safe. That ".99" theory is complete garbage. There is no performance difference between .88 or .98 volts
 

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there may be no performance gains , but what about drivability gains if you install a cam?
 

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recovering5.0L said:
there may be no performance gains , but what about drivability gains if you install a cam?
How would it make a difference? I thought the only thing the TPS did was determine the position of the throttle and establish the idle setting. Is there more to it?
 

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recovering5.0L said:
there may be no performance gains , but what about drivability gains if you install a cam?
I have everything in my sig on my car (heads/cam/intake/blower). I've run my TPS across the whole range. Nothing but problems with settings of .97 or higher, wheather they be subtle problems at times or just down right pita problems like hanging idle etc. No difference in driveability, actually much better in the lower .9's
 

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the reason why i ask is my car bucks and surges sometimes after i installled a b303. ive cleaned my iab and throttle body and set my tps to .97 its getting very annoying now. it actually seems like the car ran a little better with it set at .94
 

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recovering5.0L said:
the reason why i ask is my car bucks and surges sometimes after i installled a b303. ive cleaned my iab and throttle body and set my tps to .97 its getting very annoying now. it actually seems like the car ran a little better with it set at .94
Hmmm(?). Maybe try the idle reset procedure (clear computer, etc), and after the idle reset procedure is done set the TPS to around .92 Also clock your maf meter (that's helped me before too). Best of luck to ya'
 

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recovering5.0L said:
thanks! but how do i clock the maf?
Ooops, sorry about my slang. Actually just loosen the clamp and rotate the meter so the electronics are in a different location (then tighten clamp of course). Sometimes the actual sensor may be in an area where air velocity is slower than elsewhere in that intake tract. So by rotating the meter you might get a better air reading helping smooth out your idle a bit. hth
 

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Listen up guys...HAITHAM, you especially since I'm pretty sure I've seen you ask about this before.

There is NO BENEFIT to trying to get the TPS close to some magic threshold, whether that be the old wives' tale 1.0 or the other old wives' tale 0.98. None whatsoever. In fact, what you may very well do is cause the computer to trigger its accelerator pump enrichment mode which it will do under at least some conditions when it sees a TPS voltage of 0.97something.

So in order to avoid the triggering problem altogether, you need to get the voltage AWAY from the trigger point and make sure it stays there under all conditions (as mentioned, they like to gravitate when warm).

Therefore, set it between 0.9 and 0.95 and forget it. You won't cause the car to go to WOT any slower by dialing down the voltage a little bit. YOu could probably go a lot lower than 0.90 and never cause a problem but just for the sake of the least possible problems, set it to between 0.9 and 0.95.

I've heard some people say that older speed-density cars like 1.0v or better, but I've never found anyone able to tell me why that would be. I have the A9L computer tables here somewhere and they clearly show a trigger point at close to 0.98. Stay well below it.
 

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thanks mfe. the local mustang mechanic told me that because of my b303 's surging i shoudl set my tps to .98 . but it ran terribly rich.
 

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As a hint, you can fine tune the TPS voltage by backing out the idle speed set screw 1/4 to 1/2 turn. This will lower the TPS voltage by a small amount and not effect the idle, as long as the IAB is functioning.
 

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Discussion Starter · #14 ·
great thanks:D
 
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