My engine use to idle about right, untill I adjusted the tps sensor. The tps was pretty bad off and I was able to get it to 4.88 volts at wot. Now I got it reading pretty close to correct, my idle is way off. It's idle'd at 1200rpms instead of 650rpms. The chip is set right and I got the idle screw out all the way. When I unhook the senor it idles fine. But when I hook it up it uncorrects it to about 1200rpms.
Can any body help me do any trouble shooting here....

 

What's your TPS voltage at idle...max it should be is like .7...I believe anything less than that and the car sees idle...

4.88 is way too high of volts for WOT I think...I think anything over 4.2 or is it 4.0 is considerred WOT...

Good Luck,
GregF
87 IROC

 

from what I've always heard it's supposed to be close as possible to 5 volts at wot.
It's reading .47 volts at idle.



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86 IROC 406 tpi mass air
trickflow g2 heads
slp runners
stock tpi
about a 272 custom hyd roller comp cam
30 lb injectors
no smog,a/c,or egr
working on homemade chip
running on radials....

 

I think that this will help.

https://www.thirdgen.org/newdesign/tech/tpimod2.shtml

BW

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Bobalos
aka Bob W.
www.r71camaro.homestead.com
r71chevy@earthlink.net
<><

 

I set the idle at .54 volts on the tps. and the wot ended up at 4.55 volts.
she idles were she needs to be now.
does this sound right....

 

Well what you always have heard is from those that haven't current or accurate data.
Lots of the malfunctions statements for TPS errors start at like 4.2 for TPS being too high.

Drop your TPS back down to where it was.
if you have a scanner look at what 100% TPS you have at WOT, and I'll bet ya money it says 100%, the ecm is blind to anything over 100.

 

The important thing is the starting point & that is idle. the cpu is going to start from there & work up. if this is off it is going to associate the wrong % with the actual voltage that it is going to read in. this is going to cause you heart ache. setting this back to where it was ought to fix you up(which I think that you did).

Cause the starting point is so important we can not rely that the ending point (WOT) is going to be the same for every TPS, so the cpu looks for a voltage over 100%. one easy test (which is how i figured it out the first time) was to hook up my scan tool & then to press on the gas pedal & see where it topped out @ 100% & looked to see what the voltage is. I just checked one of my runs & found that it showed 100% @ 3.76 Vdc, & ofcorse showed 100% for all voltages above that.

hth's
BW

------------------
Bobalos
aka Bob W.
www.r71camaro.homestead.com
r71chevy@earthlink.net
<><

 

thanks guys
ya cleared that up for me

 

Bobalos, I noticed that my 100% TPS voltage also around the same (3.7x volts) when I pressed on the accelerator with the engine off, but when the engine was on and I did the same test (on the road of course), the voltage was 4.2x volts.

But all of the above is correct, don't worry about getting 4.9x volts. Once you hit 100%, you have 100%...the ecm does not allow for 100+%