[jinniu]

my 02 ses dohc. when startup, will idle at 1200 rpm w/ AC off.
Once gear shifts, it goes to ~800. Back to P or N, stay at ~800.
I once let it idle for 5-10min after it startup. It automatically dropped
to ~800 after ~5min. I thought it needed to warmup. But it was not the
case. Even with engine hot right after long drive, if I restart the engine,
it does the same thing. Is it normal?

Also, just got a new 04 ses dohc. built last oct. 24miles when i got it.
now at ~150. Just notice idle speed fluctuates from ~700--1400 at startup.
~800-1000 after warmup. is it due to breakin? or something wrong?
a/c off in all case.

Thanks alot.

 

[HotRodKush]

Sounds like a faulty MAF sensor to me, its not reading the right amount of airflow and the computer is goin into semi-limp mode

 

[shoz123]

On initial start up the SAI pump will pump air into the exhaust manifold bypassing the engine. This feeds extra O2 to the O2 sensors. The PCM will then add more fuel which results in an actual rich condition inside the cylinder. The result is a higher idle speed.

The purpose of this is to heat up the O2 sensors.

To set the idle on a '96 or newer car do this.

Disconnect the battery for a minute.

Start the car and let the idle settle down while in park.

Shift to reverse and let the idle settle down.

While still in reverse turn on the MAX A/C with the temp turned down all the way, then let the idle settle down.

With the A/C still on shift to park and let the idle settle down.


That's it.