Car doesnt accelerate as fast anymore

Khanxyz0z

Im in this weird situation, my z which has now 64k miles. Has its check engine light on, last time this happened i changed air filter and it went away, this time i took it to a local shop, thry tried changing like 3 things, air filter, intake and battery. But didnt go away,

I also want to say i wanted to trade it in to get e92 m3, so they told me they will reset and i can trade in, but im not trying to do that. I took it to a diffrent shop and they said its giving engine codes. I told them i want a solution that can fix it not just hit or miss tries here and there. Then they say the code is for maybe spark plugs, maybe coil(not suspension), maybe 02 sensor, 'since its an engine code they dont know which item to fix exactly.

I personally never really changed anything, besides doing oil changes. I dont know mabey there is some fluids i shouldve changed after 50k miles.

Lastly, one thig that happens to the car maybe once a week is that im even though im using paddles it doesnt accelerate, i fully step on the pedal but it will gradully increase speed and dont go over 3000 rpm, almost like im just rolling in nuetral at a really high speed when im changing gears, turn the car off for 3 hours and its back to normal. So i dont know if something realted to this causing the check engine light.

What i want to do is actually go to reputabile shop in the ny/nj area, and trying to avoid going to nissan dealership, which they were telling me that they wanna charge $250 just to diagnose, im like yea ok.

NISMO IX

I am pretty sure there are code readers out there that pinpoint exactly what the problem is... For all you know it could just be that the mass airflow sensors just need cleaning. You should maybe find a more competent shop and tech.

I remember seeing BrosFourSpeed on YouTube check a code on the fly and found it was his HFC and was able to clear the code too. Sounds like they want your money.

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radix023

I hate to recommend this, but take it to a Nissan dealer. Many independent shops do not pay for the subscriptions (or in some cases they are not available) to look up all the diagnostic codes. If you want to spend the money, you can get the code yourself. There are cables and software where you can read them with a laptop and there are bluetooth adapters and software for smartphones/tablets where you can read them. If you do that and post on this site, you may be able to get someone to tell you exactly what it means.

The symptoms you describe could plausibly be caused by a bad O2 or MAF sensor. A cheap thing to try would be cleaning the MAF.

Good luck. That must be frustrating as all get out.

jchammond

Agree with cleaning maf’s, as AIT is built into one of them & will pull timing if if it reads temperature above max.

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SouthArk370Z

As per NISMO IX, you need to find out which DTC(s) has been thrown. You can get ODB readers for as little as $20 or most auto parts stores will loan/rent you one. Google any DTCs.

After 64K miles, your MAFs could use a good cleaning. See comments by radix023 and jchammond above. At least one DIY on this site. Very easy job - takes about 15 minutes for a novice to do.

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Khanxyz0z

Thanks guys, appreciate the help.

I checked on youtube and some guy had the same symptoms and he cleaned the mass air flow sensor and throttle bodies, and there was a huge diffrence in the way the car responded.

Jhill

Please do not ever say a code reader will pinpoint exactly what is wrong. All a scan tool will do is give you the issue the pcm is seeing and what area the problem is in. This is where knowledge and diagnotstic techniques kick in to do testing and troubleshoot the sensor, wiring, signal etc. This is what separates a true tech from the parts changers. From his story it sounds like he has already been hit by the parts changers and this second shop sounds like they are ready to start throwing more parts.

Op it's time to find yourself a reputable shop that will actually do diagnostics, and don't expect it to be free or you can bet you've just found yourself another parts cannon shop.

Buzzkill247

Some CRC MAF cleaner, and maybe some throttle body cleaning is in order. Make sure to disconnect the neg term on the battery first. Even if you don't disconnect the plug from the MAF or the throttle body, still recommend going through the ECU reset procedure and make your ecu relearn a bit.

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 and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and 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 and 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)

Park/neutral position (PNP) switch: ON

Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine is started, the headlamp will not be illuminated.

Steering wheel: Neutral (Straight-ahead position)

Vehicle speed: Stopped

Transmission: Warmed-up
For A/T models with CONSULT-II, drive vehicle until “ATF TEMP SE 1” 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

With CONSULT-II
1. Perform EC-42, "Accelerator Pedal Released Position Learning" .
2. Perform EC-42, "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 PREPARATION (previously mentioned) are in good order.
5. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.
6. Touch “START” and wait 20 seconds.
7. Make sure that “CMPLT” is displayed on CONSULT-II screen. If
“CMPLT” is not displayed, Idle Air Volume Learning will not be
carried out successfully. In this case, find the cause of the incident
by referring to the DIAGNOSIS PROCEDURE below.
8. Rev up the engine two or three times and make sure that idle
speed and ignition timing are within the specifications.

Without CONSULT-II
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-42, "Accelerator Pedal Released Position Learning" .
2. Perform EC-42, "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 PREPARATION (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 turned ON.
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, Idle Air Volume Learning will not be carried out successfully. In this case, find the cause of the incident by referring to the DIAGNOSTIC PROCEDURE below.

NISMO IX

"...what area the problem is in," is what I meant. "...don't not..." Is a double negative btw. Thanks for the correction...

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2017 Ford Focus RS Nitrous Blue "KB43VER"
2014 370z Mag Blk 6M "KOKURYU" (Black Dragon)

Jhill

Well apple helps me make all kinds of mistakes and proof reading on a 5c is a bit of a challenge.

nandosman

Take it to an AutoZone, ask for a code read (it's free). Post codes here. Pretty sure it's gonna be P0101 and/or P010B, and the likes. I had the same issue, same symptoms, turn off the car, turn back on, and bam, power was back. Cleaned my MAF sensors 4 times, then cleaned my throttle bodies, boom, no more limp mode, and no codes either.

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jchammond

I used CRC’s mass air flow sensor cleaner (about 10$ a can)
1 can will do; spray them down very good & let completely dry before re-installation,
I wouldn’t use anything harsher on them/?as this stuff is really mild & designed for it... may take a couple good douchings of each one & be sure you’re spraying the filament/wire good.
Good practice to perform on regular basis.
Good Luck & have codes read & recorded before disconnecting batttery & clearing them off.

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Spooler

LOL, We have always called them Easter Eggers. They keep looking for the easter egg.

Khanxyz0z

So i took it to a shop to do the cleaning, but light came back on after 100 miles. got fed up took it to nissan and they said well diagnose it and all we need to do is reset ecu , i told them idk how you gonna do it just fix it, i feel like a N54 driver now, so they did their thing and light came after 800 miles. went back and they said we can change throttle bodies for 1600, im like im out.
back to the Z forum

Desert Rat

Don't throw money and parts at it. Get the codes read. Autozone does it for free, as has been mentioned.