What needs to be adjusted exactly and how?

 

Ok get a volt meter splice the power wire which i think is purple get a voltage reading above 4.3 at wot or it will throw a code thats volts.. You might want to drill a hole on the sides of the tps to adjust if you are going with an aftermarket tb.....

 

The wires on the TPS connector are black (ground), gray (+5V reference) and blue (signal). You measure the voltage between the blue wire and the black wire. Do not strip or splice any wires. Use a scanner, and you don't need to touch the wires at all. Using a volt-meter, simply pierce the insulation with a straight pin.

At closed throttle, the PCM will accept any voltage between 0.20-0.90V, and baseline that as the "0%" throttle position. That's why the factory sensor isn't adjustable.... exact voltage doesn't matter. The PCM then adds about 4V to that number and uses that as 100%, and prorates the throttle position percent from those numbers. The PCM will set codes if:

-closed throttle voltage is under 0.20V or over 1.00V
-WOT throttle voltage is over 4.90V.

Check to be sure all you voltages are in that range. Move the blades slowly to full open, and watch for a smooth increase in voltage, with no spikes.

The factory, non-adjustable TPS generally gives about 0.65V on an LT1. In theory, there is no advantage in "fine tuning" the TPS voltage as long as it is within the ranges noted above. But some people feel they get better results with a value of 0.50V and they take the time to slot the holes and adjust it they way they want it.

 

sorry i just jumped in this thread but you guys wouldnt happen to have a picture on where to slot the holes would ya ??

 

You slot the mounting holes for the TPS sensor so you can turn it slightly and increase the voltage to 0.5 or 0.6 for better throttle response.

 

thanks alot.......

 

Awesome appreciate it.

 

Do you have any evidence that 0.5 or 0.6V provides "better throttle response"? What exactly is "better throttle response"?

 

A term used to sell and promote cai's?

 

For a while I have had problems with throwing a code a WOT for "TPS Voltage Too High". I finally got around to adjusting the tps from where I had slotted it. I set the max at 4.5v and when the blades closed it settled at .31v. I had to adust it before because of the holley 58 that I use. Anyhow it does feel a little more snappy from idle in the butt-o-meter dept. now that it is adjusted. But, it would be un-noticable on the dyno or at the track ( my .02 ).

 

I hope that's the reason I'm getting the same code. @ wot I see 4.8 but I think when I gun it it spikes.

 

What was happening with the Holley 58mm that caused you to need to adjust it?

 

I was getting 4.82 @ WOT but, the light would not come on until after I was in the throttle for at least 5 sec. Maybe it takes a certain amount of cycles for the pcm to throw a code. Either way hopefully it fixed the problem. Definetly don't go by the hayes book...they said 1.2-1.6 was normal at idle and 4.5-5.0 max. GEEZ!! But, then again they don't write those books for aftermarket modification in mind.

 

Whenever I put the tb on it was showing 1.3v at idle and 5.12 at WOT. So, I had to slot the TPS to get the numbers down enough.

 

I think Ive found my problem. Did you notice anything else after it would throw a code? Any other side effects?