I have a 2002 Zo6. Just installed a Fast 90/90 and a cam kit. Car runs great. But when you come to a stop. The RPM drops to about 300 then back to 800. Idles fine once it settles out.

Is this normal or is this a bad tune??

Thanks

 

Did you get the car tuned yet? If not you will DEFF need it tuned.

 

Take it back the tuner.

 

Yes it was tuned. Is the car suppose to idle continous at 800 and not go below 800??

 

If its properly tuned, the idle should be stable. Dipping a little when you let off the throttle isn't a problem, but down to 300 is a bit much.

 

Def a bad tune

 

Was the car warmed up or still coming up to temp?

Do you notice a big dip in rpm when you turn the AC on? There are base airflow tables that need to be modified in order to get the idle dialed in.

 

The idle problem is without the A/C on. Have not driven the car with the A/C on since the install. I will tried that as well. I think I will take it back to the shop and let them re-tune the car.

 

It may not be a tune problem...everytime my 2002 has had any work done involving a battery disconnect or a power loss to the PCM, the idle then will dip to 300rpms as I come to a stop, engaging the clutch, then it goes back up to 750rpms. This occurs until I have driven it thru 6 duty cycles (about 30 miles)..Now, there is an idle relearn procedure that will return it to a steady 750rpm idle...but just driving it should cure this problem also. here's the procedure if you wish to try it:

1) Insert key into ignition and turn to the “ON” position, but, DO NOT START THE ENGINE.
2) Open the engine compartment fuse box cover and remove the two 10 amp fuses from position numbers 16 & 23.
a) According to the manual there are two fuse boxes. Use the engine compartment fuse block for this procedure not the instrument panel fuse block.
b) Engine Compartment Fuse Block (correct one): 16 is Powertrain Control Module A and 23 is Powertrain Control Module B.
c) Instrument panel fuse block (wrong one): 16 is Air Bag, 22 is Body Control Module-Ignition and 23 is Body Control Module-Ignition 2.
NOTE: Your DIC will now display “check” messages for ABS, etc… Do not worry as this is normal.
3) Turn the ignition key to the “OFF” position.
4) Return to the engine compartment fuse box and re-insert both 10 amp fuses for positions 16 & 23.

5a) Idle relearn for an M6:
1) Start the engine and allow the coolant temp to reach a minimum of 176 degrees F. Allow the engine to run at this minimum temperature for at least 5 minutes.
2) After the 176 degree, 5 minute minimum run, shut down the engine for a minimum of 30 seconds.
3) Restart the engine and check for DIC error codes (there should be none).
5b) Idle relearn for an A4: (different)
1) Start the engine and allow the coolant temp to reach a minimum of 176 degrees F. Allow the engine to run at this minimum temperature for at least 5 minutes.
2) Allow the car to idle in DRIVE, with air ON and then OFF, for 5 minutes each, and then in NEUTRAL, with air ON and then OFF, for 5 minutes each.
3) Turn the car off for at least 30 seconds.
4) Restart the engine and check for DIC error codes (there should be none).
6) Drive car for a minimum of 30 miles at varying rpm settings and speeds. PCM will now re-learn and adjust for the new air flow and temperature at the intake.
a) If error codes persist, repeat steps 1-7. Make sure fuses are properly inserted before repeating steps.
b) Do not deviate from the sequence outlined above. If you do, restart the sequence from scratch.
c) Steps 1-4 are also necessary if you ever disconnect your battery or lose power for any reason.

 

This is a problem with your throttle cracker and throttle follower. You need to have them set the parimeters properly. There is a range within the parimeters that needs to be set which is the decay.