I put on a new holley 58mm t.b. on my ported intake about 8 months ago. I have tried two new tps sensors they act the same. when idling it will show .56v when pushing down to floor it will only go to 2.60v and when mashing down as hard as I can it will only go to 3.07v. when cruising down the highway it will read about 1v. lower than my map. will this cause any running/performance problems? I heard about people slotting the tps sensors on these t.b.'s, Iv'e never done it, should I do it or not? thanks for any help.and if I have to, how do I slot it. it seem to go on the t.b. fine and bolt up fine...

UPDATE: Okay found problem, it's my new t.v. cable that controls when the car shifts I guess... I had my new tranny and stall put in a couple of weeks ago. and they talked me into putting in a new tv cable. so I let them put one in for 20.00 anyway I can take it off the throttle body bracket and the blades will open all the way. shows 100% throttle angle and 4.40v on my tps.
and when I connect the tv cable it shows only 60% throttle angle and 3.07v on the tps pushing the gas pedal all the way down. so I have to take it back and have them mess with it to get my 100% throttle back. they had about 5 inches of cable hanging out the end where it goes on the bracket. looks like for some kinda adj. and like a fool I cut it short when I got home a couple of weeks ago.because it looked like crap. now I prob. will have to pay for another cable.
one more thing, prob. a stupid question, will it hurt performance since it will not open up all the way?

thanks...

 

Have you verified that the throttle is being opened completely by mashing the pedal and the throttle cable is not stretched?

 

I'll check that out... the throttle % goes to 100% when going wot on my scanner.

 

If it goes the range of 0%-100%, you really don't have any problem. The computer is adjusting to the range of voltage.

 

Thanks shoebox...

 

You do need to verify that it is physically opening 100%. There is no need for TPS voltage to match MAP voltage...... they are measuring two different things.

Check the TPS harness wires to insure you are getting +5V between the gray wire and the black ground wire. I had a problem with low WOT voltage on the TPS and traced it back to the shop switching the blue and the gray wires in the harness connector, when they removed my electronic WOT switch from the harness. As usual, it was Shoebox who gave me a photo of the correct arrangement of the wires in the connector

 

Good point. I always assume people check this.

 

You have to elongate the holes in the TPS sensor to get your 5V. This is common with Holley throttle bodies. I used a dremel and a file to do mine.

Frank
CPT

 

do you mean the mounting holes? and am I loosing any power, or idling/running characteristics differ from normal?

 

Yeah, he means the mounting hole of the TPS. If you need to make any adjustments, you have to slot the holes.

 

You don't "adjust" the WOT voltage. You adjust (if you really need to) the closed throttle voltage to make sure its within the 0.20-0.90V required by the PCM (or at the 0.50-0.67 volts some people feel is best). The movement of the sensor should add about 4V to the closed throttle reading. The PCM looks at the closed throttle voltage, baselines it as 0% TPP and prorates up from there, on the assumption that the range of motion is about 4V.

 

Well it sits around .56v at idle.... so do you think it is allright, I will also check the throttle cable, take it off the t.b. open the blades and see if the volts will go up.

but it does sit at .56v, when I first got the new holley 58mm t.b. It was reading like really high volts like well over 100v and having a hard time idling. wanting to die alot. so I drilled a small hole on each blade and got the volts down to .56 and the car idles much better. just notice that the tps volts wont go over 3v... so I'll check out the other things...thanks.

 

Update..I found the problem, read my first post on here, still need advice..thanks.

 

Yes, if your throttle will only open 60% it will hurt your performance because when you push the pedal to the floor for WOT you'll only be getting the 60%.

 

7 years later but hope to revive this. I have a 95lt1 a4. I replaced the tps on my stock tb but it intermittently cause an engine code and the bad shifting symptoms. Since it's brand new I assume it's the way I installed it that is causing these issue. Any input on how to adjust it would be great. Thanks