86TpiTransAm

When you paperclip A and B on the ALDL and turn the ignition on I know you're supposed to be able to hear the IAC but isn't it supposed to stop after about 30 seconds so you can unplug it and set your minimum idle?? I paperclipped the ALDL and turned the ignition on and the IAC continued making noise for more than 2 minutes and it sounds quite sickly as it is. I've had a suspicion that the IAC was bad but I wanted some opinions.

Right now I have my idle adjusted a bit high because when I lower the idle back to proper rpm range and TPS voltage, the car stumbles and nearly dies when I put it in gear and in park the idle surges back and forth from 500-900rpms. Once I bump the idle up it idles just fine only high, about 1200rpms in park and 800 in drive which just doesn't sound right. Should be more like 650-700 in drive and about 800-900 in park. It's not like a have a large cam or anything that would greatly affect the Rpms over stock settings.

Rob P

iTrader: (1)

I don't think mine has ever stopped making noise when being retracted. I too have let it run for several minutes, she just keeps creaking. I think you are all right.

86TpiTransAm

Maybe the IAC is alright and I just need to adjust my TPS. I've tested the TPS and I know it's good but the voltage is at .68 volts which is out of spec from the .54 +/- .075 volts which I figured is from my idle being set too high. When I back the idle off so that the TPS is around .54 volts the car idles at about 600rpms but the idle surges and when in park it surges. 800rpm in park just doesn't seem right to me and 1200rpms in park doesn't either. I'm confused.

nblanchard

I don't know how you guys set your idle, but I leave that up to the tech guy at the dealer. I don't screw with that.

86TpiTransAm

I don't like paying someone to do something that I can do myself but whatever floats your boat, do it.

nblanchard

I do not believe in playing around with the idle setting, because with the proper diagnostic computer, you can simply select the idle.

86TpiTransAm

If people went around not believing in playing around with things on their car they'd be spending alot of money and not getting the performance that they possibly could be. Factory specs aren't always the best specs to go by. But as I said before, if that's what you wanna do then do it. We both live in free countries.

nblanchard

Oh, I fool around with my car, when it comes to performace. But when it comes to idling and other basic operations, I leave that to the dealer, cause I know you're not suppose to screw with the throttle stops, becasue it throws everything off, which why GM probably puts those little caps over the idling screw

86TpiTransAm

Or maybe they just tell you that and then put those caps over the idling screw so that they can make money off people that believe them and bring their cars in to have them do something you could have done yourself for free. Just my .02

nblanchard

Nope, cause the IAC has a certain operating range, if the engine gets air from any other place then the IAC, it screws up that operating range, which can cause engine lope.

86TpiTransAm

And that's why we have "tech articles" to outline the "proper" way to do things. Most likely the same exact techniques that the tech guys use at the dealer. Think about it.

88 350 tpi formula

iTrader: (9)

I really think you give dealer techs way too much credit. I am one and I have seen way too many idiots in the shop. they really are nothing more than lube techs with a gm service manual I went to school know how things are suppoused to work but, they can hire some high school drop out to work on your car for two years teach them a few things so that they can send them to get there ASE for a lot less. uh just letting off some steam!
and how do they fix things well they ask people like me to do it for them and if they quess and are wrong oh well its under warrantie GM gets the bill. I know a few other guys here know what I mean.

86TpiTransAm

That sounds about right Heck, my step-dad is "ASE Certified" and he can't even get a CCQJ STOCK 307 to run right. He's had the engine out of his Ford Topaz 5 times in the last 6 months and finally got it running right recently by GUESSING. On top of that, he's ASE Certified and doesn't know a single thing about the operation of a fuel injection setup.