98 GMC Sonoma Tryin to kill me $10 for Best Answer!!!!!!HELP~!!!!!?

[Chaoticdopey]

ok i have had the code read 7 times now and have replaced the IAC Valve 3 times and the code p0507 keep coming back up as Idle Air Controller "RPM's To High" when i hit about 30mph its as if the cruise control kicks in and idle stays at 1500rpms until i come to a complete stop and it is killing my breaks and killing my gas millage. i have taken it to a couple mechanics and they are stumped i have checked the TPS and its good iunhooked the cruise control hoping that would solve the problem but it didnt. i cleaned all the wires and pluged them back in hard. it seems not to do it as much right after geting off the freeway. any help would be appreciated i will even pay $10 for the best answer that solves my problem just make sure to leave your email address after you post. i'm desperate and have already spent $1300 trying to figure out what it is and do not want to spend any more
ive fixed the vacuum leaks already with no avail i cleaned the TB with TB Cleaner and i also ran some seafoam through the vacuum line which made it run less rough but right when i hit 30mph the rpms jump from 900 to 1500 and keep pulling the truck i can keep my foot off the gas and get up to 60mph without touching the gas people. ive cleaned the mass airflow sensor changed the IAC valve 3 times and ive also unhookd all the wires to all sensors on the engine cleaned themand put them back on tightly and i started the truck with the mass airflow sensor unhooked and the idle did not change at all. i also unhooked the power to the cruise control thinking that might be the problem but it was not. IM STUMPED!!!

 

[Molson02536]

Check the Throttle body blade it self for any restriction on movement throughout it's normal range or movements. Also check the EGR valve for proper operation or clean it and place back in. There was a TSB a while back for some of the throttle blades getting stuck due to excessive carbon build up by the throttle blade restriction plate on the back side of the throttle blade. Open the throttle body wide open and you can see the throttle blade restriction plate, clean it. You'll see it's really dirty or you can remove it like i did. To remove you take the two torque screws out from the throttle blade and with the throttle body at WOT, pull the blade straight up and out from the body. Once out remove the restriction plate from the blade, you can ether cut it off and grind down the edges smooth or you can remove it totally and plug up the hole with solder, some has used revits and epoxy to plug the holes. I cut mine and grounded it to a smooth edge. Once done reinstall, the blade only goes in one way so no worry's and add lock tight to the two torque screws and your done and you'll notice an increase in your HP out put and better gas mileage if you can keep you right foot of the skinny peddle. Good luck and this should help.