Just finished installing a new 52mm throttle body. Ever since then my car idles high. When it gets warmed up it idle higher in part then when i first start it. Installed a new iac valve and did the adjustment. However after i do the iac ajustment the car runs great but when i drive around for about an hour the idle come right back up again to 1000 in drive and 1400 in park. What would cause it to relearn its bad hapit of idleing high again? Looking for input and what i should check for.

 

Only problem i know that would occur is if the throttle blades were sticking open, or the tps is pushed further than normal position which is making it idle higher. Take the new one off and put the stock one back on and see what happens. Could be something up with the 52mm manufactured wrong. The speed density computer sets minimum idle so it shouldn't have anything to do with the relearning process.

 

I think you'll need a scan log, that shows the stepper count for the new IAC.

 

scan Log

 

Thanks for the replays and the weird pic of the man next to a log made me laugh. I will throw the old on back on tomorrow and post the results of what happens.

 

Put the old one back on the car and idle is fixed and car drives great. Shipped the holley unit back to jegs for an exchange. Only a 90 day warrenty on holley throttle bodys. Lets hope the new body that comes in works.

 

Guarantee that the new throttle body probably was manufactured wrong, after my aftermarket intake swap from edelbrock last year i check every aftermarket part to the stock part to make sure it's correct since a lot of tpi parts are normally made wrong these days. probably the metal valve part under the throttle body that holds the tps metal piece down for position was probably longer than your stock. did you compare to the 2 when you took the new one off?

 

[QUOTE=1989formulakid;5624442]Guarantee that the new throttle body probably was manufactured wrong, after my aftermarket intake swap from edelbrock last year i check every aftermarket part to the stock part to make sure it's correct since a lot of tpi parts are normally made wrong these days. probably the metal valve part under the throttle body that holds the tps metal piece down for position was probably longer than your stock. did you compare to the 2 when you took the new one off?[/QUOTE Ive notice that about buying aftermarket. My SLP runners seal like crap. The holley Throttle body unit would stick and bind it felt. I did not campare the two throttle body tps metel piece but your probably right.

 

just want to let everyone know my idle problem is fixed. It turns out it was a defective holley throttle body. Holley sent me another one and idle is back to normal again after an iac adjustment.

 

good to hear, reliability on parts are iffy these days