I noticed when I'm coming to a complete stop at a traffic light my RPMs drop low and the car feels like it's on the verge of stalling out. While costing to a stop sign after I push the clutch in and get ready for 1st or 2nd gear, the RPMs will drop quickly to around 500 and then jump back up to 750. The needle fluctuates between 450 and 800 RPMs all the time when I'm coasting to a stop. It's very annoying because I can feel the engine shake through the steering wheel and the shifter ***. I don't know if it's this heat wave we have, but I just got my G serviced at the dealer so I do not have a SES light on. What could it be?

Thanks,
Aaron

 

i sorta have the same problem on my 2003 g35 sedan, i replaced my plugs, and cleanded the throttle body, now it idles high at just under 1000 rpms, when i punch the gas, as the rpm's drop back it hits 1000, then jumps back up to 1500 then comes back to 1000 rpms its annoying! help!

 

Sounds to me like both of your cars need the idle relearn procedure performed. Do a search and you'll find the procedure.

 

Or, you are both running plenum spacers that have air leaks.

 

i doubt they have air leaks especially if they are stock. My car's Maf sensor was dirty and was causing some problems in cold starts and sudden clutch pedal presses. After i cleaned the MAF sensor it went away.

 

So the my skunk2 spacer is probably the reason for mine doing this?

 

My car is completely stock. The dealer did not recommend anything engine related. I will try the idle relearn procedure.

DaveB, did you ever have a Maxima?

 

^yes he did.

 

True story. I'm the same DaveB that spent way too much time over at Maxima.org. Now I'm polluting this site

 

I cant find it. Ive done a ton of searching. Can someone re-post the throttle body re-learn procedure?

 

Then that makes two of us. HAHA Just search for it on google via this site and you will find it.

 

Accelerator Pedal Released Position Learning
DESCRIPTION
“Accelerator Pedal Released Position Learning” is an operation to learn the fully released position of the accelerator
pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each time
harness connector of accelerator pedal position sensor or ECM is disconnected.

OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch “ON” and wait at least 2 seconds.
3. Turn ignition switch “OFF” wait at least 10 seconds.
4. Turn ignition switch “ON” and wait at least 2 seconds.
5. Turn ignition switch “OFF” wait at least 10 seconds.

Throttle Valve Closed Position Learning
DESCRIPTION
“Throttle Valve Closed Position Learning” is an operation to learn the fully closed position of the throttle valve
by monitoring the throttle position sensor output signal. It must be performed each time harness connector of
electric throttle control actuator or ECM is disconnected.

OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch “ON”.
3. Turn ignition switch “OFF” wait at least 10 seconds.
Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.


Idle Air Volume Learning

DESCRIPTION
“Idle Air Volume Learning” is an operation to learn the idle air volume that keeps each engine within the specific
range. It must be performed under any of the following conditions:

Each time electric throttle control actuator or ECM is replaced.

Idle speed or ignition timing is out of specification.
PREPARATION
Before performing “Idle Air Volume Learning”, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.

Battery voltage: More than 12.9V (At idle)

Engine coolant temperature: 70 - 100°C (158 - 212°F)

PNP switch: ON

Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, set lighting switch to the 1st position to light
only small lamps.

Steering wheel: Neutral (Straight-ahead position)

Vehicle speed: Stopped

Transmission: Warmed-up
For A/T models with CONSULT-II, drive vehicle until “FLUID TEMP SE” in “DATA MONITOR” mode of “A/
T” system indicates less than 0.9V.
For A/T models without CONSULT-II and M/T models, drive vehicle for 10 minutes.

OPERATION PROCEDURE

NOTE:

It is better to count the time accurately with a clock.

It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit
has a malfunction.
1. Perform EC-668, "Accelerator Pedal Released Position Learning" .
2. Perform EC-669, "Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic “PRE-CONDITIONING” (previously mentioned) are in good
order.
5. Turn ignition switch “OFF” and wait at least 10 seconds.
6. Confirm that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.
7. Repeat the following procedure quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops
blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the MIL goes off.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the
specifications.
13. If idle speed and ignition timing are not within the specification, the result will be incomplete. In this case,
find the cause of the problem by referring to the “DIAGNOSTIC PROCEDURE” below.
DIAGNOSTIC PROCEDURE
If idle air volume learning cannot be performed successfully, proceed as follows:
1. Check that throttle valve is fully closed.
2. Check PCV valve operation.
3. Check that downstream of throttle valve is free from air leakage.
4. When the above three items check out OK, engine component parts and their installation condition
are questionable. Check and eliminate the cause of the problem.
It is useful to perform EC-752, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
5. If any of the following conditions occur after the engine has started, eliminate the cause of the problem and perform “Idle air volume learning” all over again:
– Engine stalls.
– Erroneous idle.

ITEM SPECIFICATION
Idle speed M/T: 700±50 rpm
A/T: 700±50 rpm (in “P” or “N” position)
Ignition timing M/T: 15±5° BTDC
A/T: 15±5° BTDC (in “P” or “N” position)

 

I did the shortest ECU reprogram yesterday and it worked. Thanks for the help, my car feels completly different.