Map reading at idle

**V8MUSCLE** · 10-04-2015, 10:00 AM

I just got a scan tool that gives a live feed and noticed a few odd things. Ignition advance at idle is 21-21.5 I thought that was a lot map sensor reads 31-32 kpa ~9.4"hg and tps never goes below .4%
Are these normal for a 00 ls1 only mods are full exhaust car doesn't have egr or air no lean code just both rear o2 sensors have high voltage even though I don't have rear o2 sensors

**V8MUSCLE** · 10-04-2015, 10:16 AM

I also get a random low idle. ~400-500 rpm. Idle is usually around 800 unless the vehicle is moving then it's around 1000-1100.

**pajeff02** · 10-07-2015, 11:49 AM

The readings you listed all comport with what I see on my scanner for our car, although my TPS does read 0% when the throttle is closed. Have you cleaned your throttle body lately?

***SMWS6TA*** · 10-07-2015, 12:12 PM

Originally Posted by V8MUSCLE

I also get a random low idle. ~400-500 rpm. Idle is usually around 800 unless the vehicle is moving then it's around 1000-1100.

A4 usually idel around 1000 rpm
M6 around 700-850 rpm.

**speedyWS6** · 10-07-2015, 01:12 PM

Interested to read this as both my previous WS6 and my present one
both idle at around 500 once settled down after start up?

I told Steve Williams what the car idled at before his tune and it is still
500 after, so.......?

**V8MUSCLE** · 10-07-2015, 05:08 PM

As far as the idle goes once warm it idles around 800. If I'm on the highway taking an off ramp and nock it into neutral it will idle around 1100-1000 untill the car pretty much stops. It seams to randomly lose it's idle, it then seems to search for an idle, bogging down to 450-500 then surging up to 800-900. I usually force the idle to around 800-900 by keeping my foot in the gas just a bit. After 5 or so minutes of this it will return to its normal ~800 idle. It is a manual so when it is idling correctly it's right on the money.

**pajeff02** · 10-07-2015, 05:44 PM

FWIW, the factory tach may not be 100% accurate. How about cleaning the throttle body?

**V8MUSCLE** · 10-08-2015, 02:56 PM

True on the accuracy of the tach. It is a little off from the scanner watching the live feed, scanner may be off to, but when it messes up there is a huge difference in the sound and feel of the engine. When it idles low it sounds rough and shakes the crap out of the car.
It has probably done it 4 or 5 times in the 3 years 30k miles I've had it.

It is almost like when it searches for an idle after you have the battery disconnected for a while but the engine shakes more even when you use the throttle to keep the Rpms at 800 or 1000