n2oblkz

iTrader: (1)

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!

defaultexistence

iTrader: (11)

you are still getting a code?...did you modify the new tps for the aftermarket TB?

n2oblkz

iTrader: (1)

Yeah, the voltage is still too high. No, I just swapped a stock TPS in, is that OK?

mean_greenZ

iTrader: (1)

take a dremel and notch the tps sensor so you can rotate it to lower the voltage.

n2oblkz

iTrader: (1)

OK, I'm holding my spare unit and I don't see what you mean?

defaultexistence

iTrader: (11)

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

RamAir95TA

iTrader: (2)

What throttle body do you have?

mean_greenZ

iTrader: (1)

There should be a faint oval shaped outline at both ends of the sensor. cut that part out. it will allow you to rotate the sensor to set it to a lower voltage.

n2oblkz

iTrader: (1)

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?

n2oblkz

iTrader: (1)

Holley 58MM

defaultexistence

iTrader: (11)

ehh... click above mentioned link?

n2oblkz

iTrader: (1)

I skimmed through it and didn't see the WOT voltage, I'll check again.

defaultexistence

iTrader: (11)

ahh may ot show that..but if you idle is set right then WOT should be right ..i would assume ...maybe shbox's site then

RamAir95TA

iTrader: (2)

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.

mag3865

I think the voltages are ok. Closed throttle V should be .5-.9 and Wot 4.5-5 V
If you monitor the voltage as you move he throttle open it should go up as you rotate.

fergymoto

iTrader: (129)

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

n2oblkz

iTrader: (1)

Thanks everyone, fergymoto, that is a good idea, I'll have to try that first.

bowtienut

iTrader: (1)

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.

n2oblkz

iTrader: (1)

Thanks for the help guys, I'll get it apart when I get home today and hopefully get it taken care of.

n2oblkz

iTrader: (1)

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.