Hey all!!

This past weekend I did the headers and the fastman TB. Everything went smooth, started right up.. but I noticed today after driving to work and again when I got home...

It seems to be idleing alittle high.. around 800-900 RPM's in park...
I always let it warm up in the morning as I drink my coffee...when I came out to drive to work.. I noticed the idle was alittle erratic..
a slow gain in RPM, then a drop back...not a great increase.. but noticable...also.. it felt like it got just alittle rough...then smoothed out. If I sat there and rev;d it good then let off it.. I could feel it get rough....idle high a second or two.. then come down....
I didnt change the sensors when I switched TB's, so I'm assuming its one of them.. I didnt do anything to the TPS....or the MAP, ( wasnt sure how to clean a MAP sensor..) but I did clean off the IAC.. ( yeah.. I know what your thinkng.. ) anyway... I was searching and just got alittle confused so... is there a way to test the sucker??I'm thinking its the IAC because the second my foot hits the peddle.. that fastman takes off..Thanks for any replies....

 

An erratic idle as you are describing can also be caused by a minor vacuum leak. Did you repalce your throttle body gasket when you installed the fastman? If not, I'd recommend doing it. Also, double check the vacuum lines around the area where you were working to be sure that you didn't crack or knock ajar any of them. Carb cleaner sprayed on the vacuum connections and at the base of the throttle body is the easiest way I know of to locate a vacuum leak.

Hope this helps.

 

+1 Turkey hunter, doesnt really sound like an IAC problem, the truck will just die when the IAC goes to crap

 

Thanks for the quick replies guys...
Yeah.. new gasket was put on..I'll look around for a vacuum leak...I WAS laying all over that engine compartment contorting myself to get the header bolts started... might have snapped a hardline..I was thinking I may have messed something up when I cleaned the gunk off the IAC before reinstalling it...Thanks.. I'll check it out and see...the plenum is still blown so it already has a bad vacuum leak...[:@]

 

Since your plenum already has a leak, it is also likely that your new Fastman TB has accentuated a problem that you already had but didn't notice before.

 

Yeah.. I think you may be right.. The rough idle was what led me here to the forums in the first place and led me to my blown plenum gasket..I went out and did a vacuum check.. couldnt find anything leaking.. ( except the plenum) but that doesnt mean I'm not missing something... I think since the fastman went on..it may bebringing the problem out more.. I am trying to pay attention to the difference in shifting as well.. both with the OD on and off.. thanks for the replies.. I think once the plenum and everything else goes in ( a week..maybe two depending on the weather ) I will be better off to do abetter diagnosis