Stop drilling those TBs, fix stalling without computer tuning...
I've got to do something about this. Today was the first day I've actually driven the car since Saturday. It was terrible. Start the car and it idles fine for a change. Now when it warms up, you just touch the gas and the idle goes up to over 2000 rpm. So I go to work, every stop at a light, the rpms sit at 2000 to 2200 rpm for about 5 seconds and then it drops. Drive down the road and you don't even have to give the car gas, it drives itself as far as acceleration goes. You just have to shift gears. I'm to the point I'm seriously considering just getting a ported tb from Bauer or Janzen and goe from there. Is there anything else I can do? I know I could use the JB Weld and plug the hole and redrill it, I just don't have the time right now. Anybody else have any ideas?
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Originally Posted by SS125
I've got to do something about this. Today was the first day I've actually driven the car since Saturday. It was terrible. Start the car and it idles fine for a change. Now when it warms up, you just touch the gas and the idle goes up to over 2000 rpm. So I go to work, every stop at a light, the rpms sit at 2000 to 2200 rpm for about 5 seconds and then it drops. Drive down the road and you don't even have to give the car gas, it drives itself as far as acceleration goes. You just have to shift gears. I'm to the point I'm seriously considering just getting a ported tb from Bauer or Janzen and goe from there. Is there anything else I can do? I know I could use the JB Weld and plug the hole and redrill it, I just don't have the time right now. Anybody else have any ideas?
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Originally Posted by J-Rod
Has anyone ever done this (or anything similar) on a Corvette since it is drive by wire?
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From: Texas
Originally Posted by Another_User
They don't have a set screw. And the drive by wire allows for infinite increases of your airflow table (up to WOT), so you can dial it into the airflow table without fear of maxing out your IAC counts.
My understand of the way some folks work around this issue. Is to step down the IAC park position since IAC is handled by the TB, and there is no separate IAC (this closes the throttle a bit once the car is running - which on a big TB is a necessity).
Then you log the car idling at the various engine coolant temp values, and modify your idle airflow table according to the data you have logged.
I just wanted to see if anyone had adjusted the set screws on the aftermarket TBs or not...
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Originally Posted by J-Rod
Then you log the car idling at the various engine coolant temp values, and modify your idle airflow table according to the data you have logged.
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Originally Posted by BLASTER
So you are just raising the idle and going through idle relearn?
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Originally Posted by BLASTER
But you increased the turns in the set screw. Dosen't that raise the idle? Maybe I am not understanding.
ttt....im having this issues as well....im going to do alot of the mentioned fixes and see if it works...i just need someone with a stock TB so I can swap it out and see if that works...
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From: atlanta
excellent procedure. after i finished, i took out the slack in the throttle linkage that occured after the tb blade angle was changed. i cannot believe the difference this mod made after the cam.
i don't think a retune is necessary now.
i don't think a retune is necessary now.
Good thread, Another_User! I already had a 1/4" hole which was fine for the TR224 even with the A/C on, but just upgraded to a TSP235/240 and it needed some help; IAC was running 130-140 most of the time and not maitaining the commanded idle at 950 rpm. Now IAC is low and it is holding the new commanded idle at 1000 rpm. I flipped the screw also.
Originally Posted by Another_User
Since your IAC is working so hard to keep you idling, sometimes your idle will dip based on computer variables that are far too complicated for me to care about when my car won't idle right.
So I tried adjusting the throttle screw until it idled with zero IAC counts when warm, basically keeping the IAC from having the authority to lower the idle. Then reset the IAC. Works great! The PCM can always ADD air when it needs to, but never subtract it. I can rev hard or let off the gas then slam on the brakes, but the idle never faulters with my big cam. Might not be for everybody, but it works for me. Or maybe this was the whole point of this thread, and I'm just now getting it.
If I adjusted it till I had IAC counts of 0, the tps would freak out and would never go into the idle fuel cells. Yes, I reset it so it read 0% throttle, but it still wouldn't go back to idle.
Originally Posted by Hayrab
I cannot get the TPS to reset. I've got it to read 2%, and followed the steps but when I start the car after plugging the TPS back in it still reads 2%, what could I be missing?
TIA
TIA
turn your car on with it unplugged... (mabey on & off twice with it unplugged) then plug it in.... and turn on.... if it dont work you have turned the screw too much.... you will then have to drill a small hole and set the screw.