BanditTA

iTrader: (3)

GM sets the idle at 850 (according to techII) on my 02 TA. Since my TB is screwed up its been idleing at 960 (according to techII) and continues to set the high idle code (check engine light).

BigBas83

I notice a higher Idle RPM (around 1000 RPMs) on my stock 98 Trans am A4. Assuming that my tach is accurate, what could cause the idle to be high? Is there anything I should change/fix?

jmm98LS1

iTrader: (28)

The tach's on these cars are horribly inaccurate, but even more-so on 98's I've found. I've got my warm idle set at 700rpm and my tach reads 1000. My shift points are at 6400rpm but the tach needle will swing to ~7000rpm before it shifts. Don't rely on your tach.....from the factory, an a4 LS1 is set to idle at 550 in gear, 650 in gear w/ac on, and 650 in park/neutral ac on/off. Unless it's been tuned, that's what all a4 cars idle at regardless of what your tach says.

'Trust'

iTrader: (24)

My 98 tach is dead on according to HP Tuners.

NBMgreg

iTrader: (7)

my 98 has idled right above 1k, seems to be about 1050... and only 1 single time has it went below to about 850 for about a minute... not sure why it did that? but the 1k idling doesnt bother me, ill look into it when tuning time comes around.

ssmaro

HHHmmm wow there is a pretty big difference in what people have said. 500-1100???
But I went and rechecked it and its still at 950rpms, and thats after it settles down.
Are our tacks really that bad or just a difference between out cars?

Joel

SladeX

98 z28, idles 900-950 warm 1000-1100 when cold. I don't use my tach for anything more than a guide as to "when" to shift when doing wot blasts.

777

iTrader: (21)

Our tach's are really that bad. You haven't heard of people hitting the rev limiter and stuff to because the tach lag's when WOT? I know some people are more critical than others, but I don't really see it as a problem if it's just the tach being off some. I think I would be scared if one day my tach was showing 800rpms on idle, I would think somethings wrong since I'm used to seeing it 1000+ on the tach.

Domestic Demon

iTrader: (1)

According to my tach, my 98 M6 idles at about 1100RPM, fully warmed up.

So I guess thats more like 950 RPM, since smeone mentioned the '98 tachs are about 150 RPM's higher than what the actual idle is??

LS1Aggie09

iTrader: (25)

my M6 idles at aroun 800ish

miamifan3413

iTrader: (1)

I have 98 M6 and the idle has always been at 950.....seems normal to me and i have minimal mods....lid,magnaflow catback, pulley

StealthFormula

iTrader: (35)

My A4 use to idle at liek 600 or so but after tuning its at 900 and I hate it. How to I lower it?

aaron653

iTrader: (1)

my a4 idles at 1000

Smoke Panther

iTrader: (10)

my M5 idles at ~700

Hoss Ghoul

iTrader: (2)

1100 for about 5-10 seconds on start up, quickly falling to 800-1000(in PARK)...and continuing to drop as operating temps rise...then settling at just over 500 when at operating temp(IN GEAR). A4, automatic. Obviously it idles the same when the ambient temperature is less, just taking longer between intervals.

Hoss Ghoul

iTrader: (2)

One other thing, just be clear if you're talking about cold start idle vs operating temp idle. Idle in park tends to be slightly higher...cold or warm.

And in cold climates start up idle is usually higher.

1998LS1SS

iTrader: (8)

my A4 idles at 1100. how can i lower the idle? is it wasting too much more gas?

Hoss Ghoul

iTrader: (2)

You have a lid and exhaust with a tune and idle at 1100? Who did that tune? How long ago was it done? Doesn't sound good.

Throwing any codes...SES light?

Is your IAT sensor connected?

Start there...

1998LS1SS

iTrader: (8)

Will check, thanks.

Black LS1 T/A

Assuming nothing is wrong with your car, Idle is determined by a table of values within your PCM.
This may vary by year, engine package and transmission type, but here is my stock Idle Speed table (I have a 1998 A4).
(BTW, in my opinion, for our cars, at operating temperature, anything over 950 idle while in gear is really too high for my taste, even with a cam. I won't put a cam in my car that makes me idle it at 1100 RPMs. )