TPS, IAC, Throttle Body, or all 3...HELP
Car had an aftermarket ported TB on it. Had a recent tune, so I took it to the track. I got a P0123 code for High Voltage to TPS.
I borrowed a friends ported stock TB and put it on and NO problems car runs great. So, I bought a stock TB and figured I'd put it on for now. Here's what I've ran into.
I pulled my sensors from the aftermarket and put in the stocker. Car idles all over the place and after finally getting to a scan tool that will read the TPS voltage and IAC I found a problem. The TPS (and it's new) will just lose all voltage on the scan tool then send codes for Low circuit voltage.
At this point I figure it must be a bad TPS sensor. I put my friends TB with his sensors on the car and tested with scan tool. I get .51v at idle and 4.68 WOT and the IAC counts in the mid 50's. His Throttle body has been ported and looks like a bunch of mods (I'll post a pic) Car runs and idles absolutely wonderful with his stuff on it.
NEXT, I put his TPS sensor in the stock TB I bought with my IAC valve. Car has .51v at idle and 4.41 WOT (I'm guessing the difference is my friend's TB has the bump stop mod is why his goes to 4.68v) BUT the IAC counts wont come below 150 (just letting the car idle in the drive way)
NEXT I put his IAC valve in my stock TB and TPS values are the same but the car idles a little better, but the IAC counts won't come below 130.
Put his sensors back in his ported TB and put on my car and everything is perfect. Could it be something to do with his TB being ported? My car was tuned Speed Density with a ported aftermarket TB on it. Or is there a way to get the IAC counts down within spec?
TIA and sorry for the long post. Here's pics of my friend's ported stocker vs. my all stock one. I don't get why his has a hole in the bottom. If you look close you can see it.



