Hey guys, I have a major problem with my 2004 g35. I wanted to see why my car was killing so much on gas, 15L/100 km (canadian). this is what i did. I changed my air filter to a K&N, cleaned my MAF sensor with electric contact cleaner. Disconnected my throttle body from my engine and cleaned it with throttle body cleaner but didnt replace the gasket, checked my sparked plugs for any dirty plugs. restarted my ecu by touching +/-. Put everything back and now "service engine soon" light is coming on solid. And while driving seems my rpms jump up and down randomly, also it seems that my rpms stay higher then average.

anybody have this problem before? maybe i have damaged the maf sensor?, or vaccum leak at the throttle body? or spark plug issues? i have double checked all my connections. how do i check for a code? any help would be awesome thanks.

 

What do you mean you restarted the ecu by touching +/-???

 

You need to do the Idle reset since you touched the throttle body.

 

if you touch the positive wire with the negative wire that you use for the battery ( NOT touching the battery terminals). you fully restart you ecu, at least thats the way i have been told to do so.

 

hearing that is a first for me, lol.

+1 on doing the idle reset. Get the code read as well to see what's causing the CEL

 

DJ good question.. I'm in the same boat, but I have not cleaned the throttle body.. U on the right track but from what i heard. Did u leave out the gasket? If not then u have to figure out the correct way to reset the ecu. I'm gonna take my car back to the stealership and let them do it.. I know they gonna screw me over, but I don't know of anyone that knows the correct steps..Some one posted the steps but i can't seem to find them in the search form. Touching the negative and positive together seems a good idea in theory, but it also seems like u would erase the ecu unless it automatically goes back to the default

 

Accelerator Pedal Release Position Learning

Operation Procedure
1. Make sure that the 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

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


Idle Air Volume Learning (Throttle Position Learning)
It is better to count the time accurately with a clock.

Operation Procedures
1. Perform “Accelerator Pedal Released Position Learning”.
2. Perform “Throttle Valve Closed Position Learning”.
3. Start engine and warm it up to normal operating temperature.
4. Turn ignition switch “OFF” and wait at least 10 seconds.
5. Conform that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.
6. Repeat the following (steps 7a, 7b) procedures quickly five times within 5 seconds.
7a. Fully depress the accelerator pedal (HARD)
7b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the Check Engine Light (CEL) stops blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the CEL is ON.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure the idle speed and ignition timing are within the specifications.

 

Iv never heard touching positive and negative cables to reset a ECU . If its hooked to the battery it will spark and if not i cant see it doing anything . Normally you would just leave the ecu unconnected for a few hours . That doesnt sound like your problem anyway though . It sounds like you moved the flap on the throttle body and need to have it recalibrated/reset at the dealer or if it cant be reset need a new throttle body . Thats where the problem lies though .

 

gonna try the reset you guys are mentioning, respect for the advice.!

 

Make sure you're using a stop watch as the timing in the process is critical for a successfull reset

 

i had this issue when i cleaned my TB - even took it to the dealership and with the CONSULT II they couldn't get it to relearn idle. I had killed my TB

I replaced my TB and problems went away - learned the idle procedure very quick

I never use a watch so I just use a video on my phone as a stop watch

 

is there suppose to be on o-ring between the maf sensor and the air intake tube?

 

^ from what I recall yes, a plastic O-ring

 

Not on my 05. The MAF bracket screws in with 2 tamper proof torx star screws. It fits into the MAF housing directly but doesn't have an O ring.

 

Oh wait ok Mine is 2008 sedan I thought he was asking about the connection between the throttle bodies and the air filter intake. I remember there's a plastic O-ring on the throttle bodies themselves.

Sorry for the confusion.