Checked TPS voltage.

[Vettefan87]

With the key just on it reads .54 volts, and at WOT it reads about 4.4 volts. Now the book calls for around .58 volts I think... and close to 5 volts at WOT, is mine off enough to worry about it?

 

[bradfordsvettes]

it is really close enough .the computer uses it basicly for throttle position.it will richen the mix up some if you bump it up but I do not think you would gain anything from the change . there may be differnt opinions about this but you will be fine where it is for everyday applicatins Steve

 

[Edmond]

No, I don't think it's anything to worry about. I checked mine last fall and it was roughly in your area. I didn't have any problems at all and haven't had any since.

 

[Vettefan87]

Yeah, I thought with some added backpressure with running those canister mufflers it would help me out off the line, but it still wont even chirp the tires. Maybe they are just to damn sticky...

 

[Edmond]

Yeah, I thought with some added backpressure with running those canister mufflers it would help me out off the line, but it still wont even chirp the tires. Maybe they are just to damn sticky...

When I put my new Firestones on a couple years ago, it was much more difficult to break the tires loose.

 

[G Winter]

There are some offbrand tires on my 90 and with the six speed from a rolling start it it real tough to break the tires loose. With the 50 -50 weight distribution and a little weight transfer when the nose lifts just a little the vettes have really good traction. Not like a most other rear wheel drive cars. It has awsome pull in first and second.

 

[Edmond]

Oh yeah, the first to second gear pull is nice. You can really feel the force on your butt.:L Revving the TPI up to 4000rpm is nice.

 

[G Winter]

Only 4000 ??? Maybe my tach is off , mine pulles hard to 5400 . Seems mine pulls best 4200 to 5400 and pulls hard to 5800 which I don't do to easy. over 5400 makes me nervous.

 

[Edmond]

Only 4000 ??? Maybe my tach is off , mine pulles hard to 5400 . Seems mine pulls best 4200 to 5400 and pulls hard to 5800 which I don't do to easy. over 5400 makes me nervous.

Oh no, I just don't take it higher than that.:L

 

[G Winter]

I filled mine up tonight . Had 180 miles on it . 120 mile round trip included. Also took a friend for a ride and did a couple real hard runs. Also passed several cars on two lane, the peddle finds the floor in 5th. Put in 7 gals filled to the rim. And I thought I bought a sports car not an econo box.

 

[Edmond]

I've taken buddies out for rides before.

Before I put the new tires on a couple years ago, took a guy out. I was dropping him off where he worked. Place was closed and it was a big Home Depot parking lot. I let it go and he yells out, "Oh $@#%!!!" :L:L:L

Another time, I let it go on the 'Vette. My buddy says, "Man, this thing is powerful, my car sure can't do this."

And then there are the unexplained times when you just feel like gunning it. Okay, I guess the Pink Floyd solo has something to do with it.:L

 

[Moonunit 451]

With the key just on it reads .54 volts, and at WOT it reads about 4.4 volts. Now the book calls for around .58 volts I think... and close to 5 volts at WOT, is mine off enough to worry about it?

I have to disagree with the other posts on this matter. I don't recall the settings precicely, but I'm quite certain that you are not getting WOT if you don't have at least 5.0 volts with the pedal to the floor, which could well explain the performance inadequacies that you have described previously Justin

 

[bradfordsvettes]

not to be a smart guy but as long as i have been in the trade i have seen very few tps switches that read a full 5 volts at wide open throttle for the most part the ecm sees anything over 4.5volts as wide open throttle and anything between .50 to .58 would be a good idle reading but i am open to other opinions about this. I suppose there may be an ideal setting but really think the advantage would be minimal one way or another Steve

I have to disagree with the other posts on this matter. I don't recall the settings precicely, but I'm quite certain that you are not getting WOT if you don't have at least 5.0 volts with the pedal to the floor, which could well explain the performance inadequacies that you have described previously Justin

 

[wishuwerehere82]

I filed the slots on my TPS on my '82 to get the extra 1/2Volt out of it. It biases the angle of attack on the linkage. That way I can get the minimum and maximum voltages out of it.

 

[Vettefan87]

I have to disagree with the other posts on this matter. I don't recall the settings precicely, but I'm quite certain that you are not getting WOT if you don't have at least 5.0 volts with the pedal to the floor, which could well explain the performance inadequacies that you have described previously Justin

Okay, maybe we are getting somewhere now... How would I adjust this to get the extra little voltage out the low side, and the little over half volt at WOT? Wish, could you explain how you filed the slots? I am sure the TPS sensors are similar for your 82, and my 87, if not identical. Thanks.

 

[Moonunit 451]

I filed the slots on my TPS on my '82 to get the extra 1/2Volt out of it. It biases the angle of attack on the linkage. That way I can get the minimum and maximum voltages out of it.

That's interesting. The couple of times that I have gotten close to the book specs my car just idles too high, so I get it as close as I can and make sure that is is at or over . 5 volts at WOT, but I can definately see your point on how filing it could get you to specs

 

[Vettefan87]

Is there anything else that I need to do other then adjust the TPS? What if the idle goes to high, just back the TPS down a little?

 

[wishuwerehere82]

Okay, maybe we are getting somewhere now... How would I adjust this to get the extra little voltage out the low side, and the little over half volt at WOT? Wish, could you explain how you filed the slots? I am sure the TPS sensors are similar for your 82, and my 87, if not identical. Thanks.

The TPS on my '82 has two arced slots that hold it to the TB.
The total resistance fron center terminal to outside terminals is 12Kohm on both sides. One is 0 Ohms at rest and the other is 12K at rest. As the TPS wiper as rotated the rsistance changes from 0 to 12K on one terminal and from 12K to 0 on the other.
The wiper on the TPS rests on the throttle linkage and is calibrated at idle to book spec.(mine is 0.525 V @ 650 RPM) When the throttle linkage is at WOT the maximum is 5.0 Volts.

Since the mounting screws are arced the only adjustment is to rotate the TPS body to set the minimum voltage adjustment.
By filing the slots, the TPS body can be moved closer to the center of the throttle linkage's center or rotation, causing the angle that the TPS wiper rotates to increase. So by moving it closer you can adjust it to the idle setting and get the 5.0 V on the WOT position. This results in a richer fuel/air mixture at WOT and still gives the proper idle mixture that the computer will read.

 

[wishuwerehere82]

Is there anything else that I need to do other then adjust the TPS? What if the idle goes to high, just back the TPS down a little?

If the idle goes up, turn the idle stop screw back out to get to idle speed, then reset the TPS voltage. You may have to go back and forth a few times to get it perfect.

 

[wishuwerehere82]

That's interesting. The couple of times that I have gotten close to the book specs my car just idles too high, so I get it as close as I can and make sure that is is at or over . 5 volts at WOT, but I can definately see your point on how filing it could get you to specs

The idle stop screw sets your speed. The TPS voltage sets the mixture at that speed. It also tells the computer to close the EGR valve and a few other things.