tps question...

peterkin

..it isn't rocket science
i just looked at the run i did at the track saturday again this morning on turbolink. i was watching the tps and it never got over 4.16v, and i was trying to put my foot through the floorboard. what could be wrong, it's .43-.44 at idle and 4.66 at WOT. what could be wrong? should i reset it for a higher WOT voltage like 4.90-5.00 or something. that might be why i get the little bit of knock that i do when i get on it, also that might be the reason i couldn't really break 100 mph at the track saturday. i got 99.96 on one pass and 101 on the other pass. i was expecting a little more. any insight would be greatly appreciated.
 
also, is .812mV rich going across the line in third gear. 14-15lbs of boost, and 43psi fp by the way.
 
You might take a close look at the throttle body's operation,, you know, with the up pipe off(engine off), and verify WOT with someone flooring it from inside the car. Also, perhaps the TB shaft/bushings are worn and the TB shaft is crocking sideways a little when it's nailed, so it's not opening all the way. I guess I don't have to suggest the floor mat was in the way?
Also, TPS should read >4.50 when flooring it from inside the car.
Oh, TPS voltage may read .02 or so volts less, engine off, as opposed to engine on.
 
If you believe the folklore that says you need some magic number you all can file away.

Anything that is at least 75% of full scale (5.0v) is fine as per the code in the chip. I wonder how those o2s got so rich if the car was not into Power Enrichment?

Go look at the code printout supplied by Dave Huinker on www.gnttype.org and look down around line 1400 for tps vs PE and you will see the same value of fuel trim for all values of 75% and greater...

If you examine the code back up the listing, you will find that PE is also invoked by LV8 and that is the reason that you that have DS will see PE down in the tps values in the 2s when you give it some gas.
 
Depends on how you check TPS... are you setting this with the laptop? If so, check it like you drive it - with the pedal. Some folks grab the throttleblade and move it by hand (or with a screwdriver). Also, remove the floormat :D

Using a meter works well also just harder to do since the leads are fairly short. I assume you are doing this alone.

Finally, MOST TR's will read higher base ref voltage with the car running. Set for .40 at idle engine OFF and it will likely be .42 running.

S
 
Did you remove your floormat?

May sound kinda stupid, but I know some people have thick aftermarket floormats, and you can't get the pedal down all the way.
 
i think i remember distinctly moving the floor mat back, but i'll check again this weekend or so....i'll get back to you guys on this.
 
nobody is paying attention.....if your TPS is a 3.75 volts, you will have PE...now, whether your throttle body is wide open or not is another question..............pull the pipe and look at it!
 
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