98BirdLS1

I just installed LT headers and a ported throttle body on my car this weekend. My friend and I are also fabbing true duals. Since we didn't get everything done in one day I drove around with an open x-pipe, no mufflers.

When I'd start the car, it would idle around 1500 and then slowly drop to 1200 with the a/c off. When I turn the a/c on it would drop down to 1000. What is causing the car to idle so high?

I figured I'd try and adjust the idle adjustment screw and to the computer relearn trick after we put the the mufflers on, but I don't what else would cause it. Any ideas? Thanks in advance.

Luke

00PewterSS

iTrader: (3)

I forgot to plug back in the temperature sensor on the LF of the engine block. I uplugged it to get better access. I didn't notice it was reading no engine temp, but did notice the high idle. When I scanned it, it showed low voltage reading on that sensor and that is how I found it.

Brian

98BirdLS1

Everything is plugged in. I finished up the exhaust today now it idles at 1000 with the a/c on and 1200 with the a/c off. Anybody have any ideas??

618HAWK

iTrader: (361)

Did you remove you IAC & TPS units for porting? Might have something stuck under the IAC pintail (sealing area) Pull it out and clean it. Might have damaged your TPS sensor. Do you have a way to read the values-position? If not try and disconnet it when running and see if idle returns to normal, if so your problem might be with the TPS.

777

iTrader: (21)

Is this your TB core or did you get it from somewhere else. I imagine either the hole was drilled for a cam, or the set screw is set high. I suppose your tach could be off, but not that much. See if you can borrow a non-ported throttle body (or if you have the stock one) and put it back on. If that doesn't change the idle then it is something else. I would check easy things first though.

01 Red WS6

iTrader: (4)

when I put in my ported TB it did the samething. Once I drove it around it was fine. If you still have a problem I would think its the hole in the blade or the TPS

GuitsBoy

iTrader: (4)

Were you extremely careful not to touch where the blade seals with the bore? Even if you only opened this up by a couple thousandths, youre now letting more air throught at idle. Try sealing the hole up with a nut and bolt and see if that makes up the difference.

WS6FirebirdTA00

iTrader: (33)

yeah man when you port the tb it might do that the first few start ups, should be fine after that as long as the headers arent messing with it as well

Lithium

iTrader: (47)

The guage could be wrong as well, I think that its the 98's that have that problem.

98BirdLS1

How would the headers mess with my idle? I've been driving it alot and it still has a high idle, adjustment screw is down as far as it will go without binding the throttle blade. I haven't checked the idle hole yet.

I guess I am going to swap my stocker back in to see if it makes a difference, if it doesn't I'm going to find someone with a tuning program to see if we can find out what is going on.

Luke

WS6FirebirdTA00

iTrader: (33)

i dont think the headers would i was just saying that it is most likely the tb though