FirebirdStud

iTrader: (5)

I am stumped here. I have two TPS sensors, and both are having the same problem. The one that I have been using is slotted, and I got the voltage down to .29v at idle/rest. It still registers at 100% throttle when I put the gas pedal down to the floor.

The problem is this, driving along is fine, but when you take your foot off the gas, the TPS still registers about 2%, so the car wont idle, cuz it thinks you still have your foot on the gas. But, when I blip the throttle, it will go to 0%. Very annoying. I thought it was the throttle blades were not closing all the way, so I put another spring on it to pull it back, but did absolutely nothing, so that is when I started datalogging it to figure out what was goin on here.

So, I swapped out the TPS sensor for another one I had laying around, unslotted. At rest it registered .70v. I didn't care, as its unimportant. I just wanted to see if it would go to 0% after you slowly pull you foot off the gas... so I tried it. Same damn thing. You have to forcefully blip the throttle to go back to the idle state, at 0% throttle.

So, I measured the shaft of the AS&M TB, and it was .156". I measured my stocker, and it was the exact same. So, what is causing the TPS sensor to not go back to 0% when you slowly pull your foot out of the gas, but if you forcefully blip it, then it will go to 0%??

I am very confused, and I want to get this fixed asap, cuz Im gearing up for another dyno day next saturday!

Thanks for any and all advice!

~Cody

FirebirdStud

iTrader: (5)

FWIW, I stuck a screw driver in the end of both sensors, and the springs are still very strong that bring it back to its resting state. I cant figure out what would keep it from going back to 0% when you let off the gas slowly, but if you nail the throttle like your wanting to race or something, then it goes to zero. And two sensors do this, one slotted and one not.
No one has had this problem before??

FirebirdStud

iTrader: (5)

No one has had this issue before?? I find this very hard to believe!

96slow6

Yes i had an issue on my holley i just cleaned all the buildup inside the slot its self and took some material off with my dremel. Then i used multi meter to set it right. I had to wobble out the mountting holes also to get it just right.

siniSSter

iTrader: (2)

I've got a Holley 58mm that does the same thing. It was annoying at first, but I guess I just got used to it.

smoknta

Its not the sensor, its the throttle body. I have heard of this problem, and an extra strong spring added fixed the problem. If both sensors are doing it, that kinda rules out the sensor being the issue. I bet if you swapped out throttle bodies the problem would go away.

FirebirdStud

iTrader: (5)

yup, exactly! Turns out that I bought someone else's nightmare.

The plastic end that the throttle cable connects to was loose on the shaft. So I took the TB off again, and sure enough, when I took the bolt out that holds the plastic plate to the shaft, the thing was butchered! So, the plastic plate would move a little on the shaft, then the shaft would move, thereby creating a new idle position when I let off the throttle. I wish I could remember who I bought this used AS&M TB from, cuz I would fly to their house and personally punch them in the damn face. It seems all my problems stem from a effed over TB. So now I have called AS&M, and ordered me a new shaft, plastic peice, and the spring piece, as well as the stop arm. $130 dollars later Im not a happy camper. I hate the russian Roulette you play when you buy used! I hope I can get it all squared away before saturday for the dyno, cuz I really want to do a damn money pull on my fireturd.

If it wasn't for bad luck, I would have no luck at all.

FirebirdStud

iTrader: (5)

Well, update time. I got all the parts to rebuild the throttle body, and guess what?? No more stupid TPS issues. Funny how 130 dollars later they disappear!

So, now that I have that cleared up, its time to load in some new programs... (thanks Chris!) and do some datamaster loggin to get this beast on track for Rippies Dyno day! Woot Woot!

Steve40th

Check for full throttle on the AS&M. If it wont go to full throttle, I had to grind the inner part of the plastic cam that the throttle cable goes to to allow it to full come back to idle. We found on the Vettes that the problem wasnt it not going to full throttle, it was the Throttle body wouldnt come back to idle when it was adjusted for full throttle.
The white line is how far I ground the valley down un the throttle cable valley it rides in.

FirebirdStud

iTrader: (5)

oh wow man. I just checked mine, and it does go to 100% throttle when I floor it, so looks like that is not an issue on my particular car. But this is interesting stuff here! This is what I like to see, peoples problems, AND how they FIXED it.
Thanks for your experience!!