TPS voltage too high at WOT??
TPS voltage too high at WOT?? I have just finished having a cam install done on my car, complete with Madz28 tune and full bolt ons. The car runs very strong and everything seems just perfect, except, I throw a TPS code at WOT. A check with my Scanmaster shows the TPS voltage at idle being .64 and at WOT, it's 4.86. I installed another TPS (new AC Delco) and the TPS voltage was .64 at idle and 4.88 at WOT. Anyone have any ideas?? This is on a new Holley 58 MM TB.
Thanks!
Thanks!
Last edited by n2oblkz; Sep 13, 2010 at 06:20 PM.
ehh...you elongate the mounting screw holes so's it can be slightly adjustable www.golenengineservice.com/html/tps.html ...i would disregard opening the blades unless you have a motor needing the extra air.... you may need to close the blades for proper idle then adjust tps to proper voltage...If any of this is the issue.... check your wires at the TPS for exposed/faulty wiring issues
Last edited by defaultexistence; Sep 13, 2010 at 07:38 PM.
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Verdad Gallardo OK, thanks, that's what I was looking for, I have my scanmaster hooked up, so it should't be that much trouble. Does anyone know what the WOT TPS voltage should be?
The way the TPS works (in terms of voltage) is that idle voltage can be anywhere between .2v and .9v (contrary to the popular belief that .6v is critical). From then on, the PCM will prorate the movement of the throttle blades by about 4v to WOT. If the voltage exceeds the 4v increase expected by the PCM then the SES light will set (only at sustained WOT).
The Holley is your problem. Many times the throttle blades go too far past WOT and will set the TPS voltage higher than the ~4v increase from idle the PCM is looking for. The solution? Have the code tuned out by the PCM. You can also turn the voltage down to around .3 or .4v at idle and see if that helps as well by doing the "slot" mod mentioned above.
The Holley is your problem. Many times the throttle blades go too far past WOT and will set the TPS voltage higher than the ~4v increase from idle the PCM is looking for. The solution? Have the code tuned out by the PCM. You can also turn the voltage down to around .3 or .4v at idle and see if that helps as well by doing the "slot" mod mentioned above.
I went through this with my Holley 58mm and like Joe said, the throttle blades do rotate past WOT. This is the cause of your TPS high voltage code. It is also bad for airflow because the air coming in will be directed UP into the roof of the intake manifold rather than straight into the plenum. I made a throttle stop for mine out of 1/4" aluminum and bolted it to one of the throttle cable bracket bolts and adjusted it accordingly. Making a throttle stop would be the best thing to do in my opinion.
You can see the throttle stop I made in this picture. Pretty simple
You can see the throttle stop I made in this picture. Pretty simple
fergymoto is correct. It's a common issue on Holley TB's.
Use a throttle stop to prevent the blades from boing past full open, and you'll fix the airflow issue and the TPS over-voltage issue all at the same time.
Use a throttle stop to prevent the blades from boing past full open, and you'll fix the airflow issue and the TPS over-voltage issue all at the same time.
Thanks for the help guys, I got a throttle stop fabbed up tonight and it works perfectly. TPS voltage at idle is still .64 volts and WOT is 4.78 volts. Worked out well and looks nearly stock.
