Idle setting Procedure?

**Z34LS1** · 07-11-2012, 06:30 PM

I'm Sorry if this seems redundant but my search yielded no results.

My idle is a little high when cold, near 1100. Once it warms up idle drops to about 700 in or out of gear.

My cars a 98 T/A, CIT, tuned, headers, 3 inch exhaust, EGR delete.

I thought I read a post on setting the idle in gear on an A4 like mine?

Thanks for your time.

Maybe this idle is normal? It only seems to be when cold.

Just installed new iac and tps last week, idle was good till iac took a dump.

**Too Fast** · 07-11-2012, 06:34 PM

Sounds perfectly normal. There is no idle setting procedure, only a parameter for the PCM. Sounds like all is right with your car. It will learn how to idle after 5 to 10 miles driving.

**Z34LS1** · 07-11-2012, 06:54 PM

Right on, Thanks for the Reply. I only have about 2 miles on it since the iac and tps.

**0rion** · 07-11-2012, 10:12 PM

an 1100 rpm idle isn't normal.....an idle relearn is basically just starting the car and letting it idle in park a/c off for 5 min, park a/c on for 5, in gear a/c off and on for 5 each but I don't think that's your issue. That idle will relearn itself without doing that. Sounds like you have some form of un-metered air getting in there. Once the car is up to temp your idle should be 550-650. Have you checked for leaks after the MAF or vacuum leaks?

**Z34LS1** · 07-12-2012, 02:23 AM

Hi Orion, Thanks for responding too.
I Definately do not have any vacuum leaks. Every line has been replaced, as well as the connectors holding them together.
I was reading about low fuel pressure? I can ccheck that tonight.
The tune was done prior to the headers and 3 inch pipes. It's odd though because before the iac went out I had no idle issue.
I have not ran through the procedure you mention above yet because My a/c is not hooked up yet.
I am trying to get my Tuner to come record some numbers, last time he noted I was running lean at around 25%, for whatever reason we had to pull my puter to upload the tune. Rear o2's were turned off as well as EGR....

**Too Fast** · 07-12-2012, 02:34 AM

If it was that lean, fuel trims of +25%, that would indicate a vacuum leak or low fuel pressure. However, you'd notice the low pressure in other ways like hard starting, loss of power, hesitation. And since you've only driven about 2 miles since the new IAC/TPS, it's probably still learning, and the idle issue will fix itself. Unless your tuner made some adjustment to the cold start idle? My car always has about a 1000 RPM cold idle, for the first minute or so, then it's about 700, and has been like this for 7 years, the custom Frost tune changed nothing about the idle (I didn't request anything different, just hoping for a bit more power like we all want).

**Z34LS1** · 07-12-2012, 08:02 AM

Originally Posted by Too Fast

If it was that lean, fuel trims of +25%, that would indicate a vacuum leak or low fuel pressure. However, you'd notice the low pressure in other ways like hard starting, loss of power, hesitation. And since you've only driven about 2 miles since the new IAC/TPS, it's probably still learning, and the idle issue will fix itself. Unless your tuner made some adjustment to the cold start idle? My car always has about a 1000 RPM cold idle, for the first minute or so, then it's about 700, and has been like this for 7 years, the custom Frost tune changed nothing about the idle (I didn't request anything different, just hoping for a bit more power like we all want).

Well your first line sounds spot on, and the Fuel trims were at 25% however as you stated I had a Massive Vacuum Leak on the PCV Fitting above the Passenger side valve cover. As to the Hard Starting I do every once in a while have it not Fire Immediately, and if it doesn't fire I stop and the Second time it Always Fires.
I thought I had the once in a while start issues solved BUT......it seems the gremlins are still around.
As to Hesitation It's no More than I have in my C5, or LT1, all three have a split second after the throttle is mashed before they come alive so I'd say no to Hesitation.

The Only thing that was Slightly Different in my Tune was the Percentage of Lock Sent to the Torque Convertor if I am remembering correctly, I may be wrong on that because I had the 5.3 in our Avalanche done the Same night as the Lumina.

Avalanche is nipping at 21 mpg on Average, and it weighs 5960lbs.

**Z34LS1** · 07-27-2012, 09:04 AM

Just a Follow up to the Thread.....
My Idle Smoothed out Nicely after about 10 miles of drive time.
My Car still runs like Crap until 160 degrees, once i hit that Temp it's on.
Does Anyone Else Have this Issue?
I can deal with it, not really a big deal at all.