We are doing the throttlestop mod tonight. My friend has auto tap(newer ver DOS). He said he caouln't find the trottle open reading. Any HELP ON USING AUTO TAP or a standard volt meter??

Thanks
<img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />

 

Tell him to look for the throttle position sensor. You should see 4.4 at WOT.

 

As long as you keep it [below] 4.7 volts at WOT, you won't set an SES light.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Kimchee and Rice:
<strong>As long as you keep it [below] 4.7 volts at WOT, you won't set an SES light.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Wouldn't the *right* way to do it be to adjust the mechanical throttle stop until floorboarding it makes the butterfly valve dead-nuts horizontal, then trim the pot so that it passes 4.5 volts (or whatever is right) at that position? The pot might also need to be calibrated at the other extreme. I presume the OEM pot doesn't have those adjustments, or people would use them. After-market parts makers, take note. Yet another part you can make for a few bucks and sell for 80.

Another idea. Once you file the throttle stop, if the pot passes more than 4.5 volts or whatever at WOT, couldn't you just solder a small resistor in line to drop the voltage a tad?

<img border="0" alt="[Corvette]" title="" src="graemlins/corvette.gif" />

 

Following up on my own post here...

Thinking about it some more, you would need two resistors, one in parallel and one to ground, to make the fractional adjustment independent of current. However, there would still be problems. We're talking about tweeks in the range of 5%, and even really good resistors are sometimes not that accurate. Hmmm... and then there's temperature variations...

Other possibilities: 1. An op amp with an adjustment screw on it. Easy enough. 2. A small processor controlling an op amp. It would still be cheap to make, once you wrote the little program to run it. Put a "learn" button on the housing. Press the learn button when the foot feed is not depressed, and release it after you get to WOT.

Okay, I'm through rambling now.

 

or you could just not go past 4.5.....

<img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

How would you go about doing this with a volt meter? (for those of us w/out atap)

<img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

I ended up @ 4.63V with the TB blade at 90*. I think I remember 100% indicated throttle position was around 4.2V via Autotap....
I did mine with a voltmeter. Just get some straight, single strand wire like telephone wire and stick right down next to the wires on the TPS sensor and you'll have a way to hook up a voltmeter. You'll know you have the right two when you get a voltage reading when switch is on, and the voltage will increase as you move the throttle. I think it's the blue and black wires for the Pot.

Edit: I found my old notes and I started out at 4.36V @ WOT and ended up at 4.60V @ WOT.

<small>[ May 08, 2002, 08:22 AM: Message edited by: gwj ]</small>

 

On some makes the TPS pot is somewhat adjustable,
using slotted mounting holes; you can loosen and
reposition (to the tune of a few degrees anyway).

I don't know about the Camaro TB (yet). But, you
could go take a little rat-tail file to the
mounting holes and do the same thing I reckon,
and not affect anything except the alignment of
electrical to mechanical opening. If it isn't
already good-to-go.

Adding series/parallel resistors without
affecting either idle or WOT seems not-so-
likely, and a little bit of filing is easy
to do.

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> Wouldn't the *right* way to do it be to adjust the mechanical throttle stop until floorboarding it makes the butterfly valve dead-nuts horizontal, then trim the pot so that it passes 4.5 volts (or whatever is right) at that position? The pot might also need to be calibrated at the other extreme. I presume the OEM pot doesn't have those adjustments, or people would use them. After-market parts makers, take note. Yet another part you can make for a few bucks and sell for 80.

Another idea. Once you file the throttle stop, if the pot passes more than 4.5 volts or whatever at WOT, couldn't you just solder a small resistor in line to drop the voltage a tad?
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">