High Revs at Idle- Micra K12

Hi there,

Having issues with my 2006 1.2 Micra... again!

When you start the engine, it revs up as usual and then it sits at 1500 revs and doesn't go down. It also does it when you put the car in neutral for several seconds before it goes all the way down again.

Has anyone had the same problem, or know if there is a fix for this? Only had the MAF sensor done last month which set me back £170...

Any help would be much appreciated!

Cheers, Lucy
 
Hi @chriswills

Is it relatively easy to check these seals and are they easy to find? It's super annoying as it has been to garages and they can't find the issue.

It's particularly bad on a cold start, sounds like i'm over revving and it's using more fuel so I just want it sorted out, but literally don't know what to do from here.

Thanks,

Lucy
 
Hey,

Thanks for your reply! So when it starts its up at 1500 revs, then over the space of about 5 minutes it very slowly decreases down to about 900/1000 revs. As it's going down the needle slightly twitches up and down and you can hear the engine idle change as it does this.

When I just went outside I revved it and listened to the engine. I did notice when I rev, a veryyyy faint almost chugging/popping sound when the revs come back down to normal- I don't know if this helps?

Thanks,

Lucy
 
Yeah relatively simple to check. Any garage who do spark plug changes can check them as they are between the throttle/air housing box and the inlet manifold. Only 6 bolts to undo and the top of the inlet manifold is right behind the engine but at the top so easy to see. Sometimes when the box is removed the seals stick to it. Believe they can be checked without removing the air box, with engine running spray a combustible spray around the back of the air box and if it causes a rise in engine speed that would suggest the seals are leaking.

Sent from my MotoG3 using Micra Sports Club mobile app
 
Ok thank you. I will ask a garage to have a look for me.

I read another thread and they mentioned that it might be the following things...
  • Idle control valve sticking- may need cleaning?
  • Coolant sensor (might be why it is using more fuel? But wouldn't the engine light be lit for this?)
  • HT Leads
  • Spark Plugs
Do any of these seem relevant to you? Sorry for 100 questions, It's just one of those frustrating problems that I think I need to investigate before I spend even more money at the garage for them to tell me they don't know...

Thanks, Lucy :)
 
Excessive idle speed on start-up K 12 Micra?

The following reference sources imply it is possible that accelerator position sensor and throttle body stepper motor ECU fly by wire digital data communications system needs calibrating after any one of the electronic modules was momentarily disconnected by unprofessional erroneous trial and error attempts at troubleshooting?

References;

1)http://www.noteownersclub.co.uk/forum/how-to-correct-high-revs-at-idle_topic1796.html

2)https://www.launchtech.co.uk/common...ERFORM IDLE AIR VOLUME LEARNING ON NISSAN.pdf

Due to its technical nature there is a dearth of uncommon free K12 technical expertise on this forum and changing parts at random is unlikely to solve the problem without calibration/ resetting.

You have not recently mentioned data trouble fault codes and any recurring oxygen sensor fault codes that merely confirm erroneous air fuel mixture possibly due to low fuel pressure, injector, throttle body and or M A F airflow sensor malfunctions or input air leaks due to perished split hoses, manifold gaskets or injector seals to name a few.

May I suggest that it would be more cost efficient to take it to a Nissan Specialist in your area as they will know how to assess, investigate, test and diagnose the faults with only a detailed description of all the symptoms of the issues that you are experiencing with your vehicle?

May I also suggest that you avoid Nissan main stealer dealers as they will price gouge to maximise sales commissions and their profits, potentially rendering your eleven year old vehicle beyond economic repair.

Perhaps you can reconsider the cheaper choice of ignoring the issue as the vehicle is still driveable or perhaps consider selling it on?

Search the Good Garage Guide in your area and also for Nissan Specialists in your area.

Reference: Daily Telegraph motoring correspondence good garage guide in your area.

http://www.honestjohn.co.uk/searchs/?q=Good+garage+guide

Good luck taking control sorting these issues that seem to be long outstanding in your many posts since Dec 2015?

Perhaps someone on here can come up with an alternative strategy and detail plan how to rationally resolve these idle issues more quickly and cost efficiently?
 
Excessive idle speed on start-up K 12 Micra?

The following reference sources imply it is possible that accelerator position sensor and throttle body stepper motor ECU fly by wire digital data communications system needs calibrating after any one of the electronic modules was momentarily disconnected by unprofessional erroneous trial and error attempts at troubleshooting?

References;

1)http://www.noteownersclub.co.uk/forum/how-to-correct-high-revs-at-idle_topic1796.html

2)https://www.launchtech.co.uk/common-procedure-pdf/HOW TO PERFORM IDLE AIR VOLUME LEARNING ON NISSAN.pdf

Due to its technical nature there is a dearth of uncommon free K12 technical expertise on this forum and changing parts at random is unlikely to solve the problem without calibration/ resetting.

You have not recently mentioned data trouble fault codes and any recurring oxygen sensor fault codes that merely confirm erroneous air fuel mixture possibly due to low fuel pressure, injector, throttle body and or M A F airflow sensor malfunctions or input air leaks due to perished split hoses, manifold gaskets or injector seals to name a few.

May I suggest that it would be more cost efficient to take it to a Nissan Specialist in your area as they will know how to assess, investigate, test and diagnose the faults with only a detailed description of all the symptoms of the issues that you are experiencing with your vehicle?

May I also suggest that you avoid Nissan main stealer dealers as they will price gouge to maximise sales commissions and their profits, potentially rendering your eleven year old vehicle beyond economic repair.

Perhaps you can reconsider the cheaper choice of ignoring the issue as the vehicle is still driveable or perhaps consider selling it on?

Search the Good Garage Guide in your area and also for Nissan Specialists in your area.

Reference: Daily Telegraph motoring correspondence good garage guide in your area.

http://www.honestjohn.co.uk/searchs/?q=Good+garage+guide

Good luck taking control sorting these issues that seem to be long outstanding in your many posts since Dec 2015?

Perhaps someone on here can come up with an alternative strategy and detail plan how to rationally resolve these idle issues more quickly and cost efficiently?

Thank you so much for this information @plmval . It's a tough one as I want to sell it on but I'm quite honest and don't want to sell onto some unsuspecting person and rip them off. I was thinking of PX but then they may only give me peanuts for it given it has issues.

The car did show a fault code for the MAF sensor about two months ago, the engine light has turned off since it was replaced and set me back £150...

I will have a read of the forums you have sent over, thank you. I have been avoiding Nissan dealers like the plague too as I have read they rip you off but I will be sure to look for a Nissan specialist instead. Are you a Nissan specialist yourself?

Thanks again, Lucy
 
Hello I have the exact same problem over the past three months ive spent over 700 on trade parts full service and alot more even if I slightly toucj acceleration it jumps to 1.5 rpm and stays for 5 seconds if I go to 5000rpm it slowly goes down but allways stays at 1.5rpm for a few seconds did you find out exactly whats wrong
 
Whenever your engine is idling oddly always look for a vacuum leak. This can throw a mad code. If you had the maf diagnosed and replaced the issue persisted the diagnosis was not correct !!
 
Hi. I am having a similar issue with a k12 1.2 I bought the car at the beginning of this month for my girlfriend and last Saturday I noticed the revs were high when she started the car. I thought she had her foot on the accelerator! They were at 1500rpm. We drove about 40 miles and I got her to let it idle. It had dropped a bit to 1100rpm but has never dropped lower. I did check the inlet for leaks, cleaned the throttle body, and sprayed combustible liquid around the engine but it didn't rev the engine. I have tried the recalibration but never got any feedback from the car to show it worked. I have checked for error codes but there aren't any. I did see the idle vacuum was about 24 which dropped to about 17 when I revved the engine. Is 24 a normal vacuum reading at idle? Does anyone have any other suggestions as to what it could be? Thank you (and apologies for hijacking the thread). Simon
 
I have checked the coolant temperature and it started at 21c and after a few minutes the temp had risen to 80c. As it did this the revs slightly dropped from 1500 to 1300 rpm in response.
 
Thank you. I have tried the calibrations again but still no joy. The MIL light plus the other dashboard lights are always on when the ignition is on and the MIL light doesn't flash. I tried the procedures with the key just on position one too to see if that worked. Any ideas? I have done everything I can think of and followed the instructions. My car just doesn't respond.
 
The issue and solution: Nissans had years 2000 - 2010 the problem that rpm was fluctuating at idle and the car did not pass the technical inspection because of environmental and showed rich fumes. This was very common in Micra's, but not only on those. The reason was the front lambda, which is giving data to ECU, which is controlling the motor; it did not work properly. Even if you changed the lambda the issue did not disappear. The basics for the reason was the earthing issue of the lambda. In ECU, the earthing had problems and did not work properly; that is why changing the lambda did not help any. SOLUTION: Just add an additional earthing wire for the front lambda's signal measurement. The same earthing wire is connected to the rear lambda earthing - so actually with that one wire, you fix the both lambda's signal wires' earthing issue. HOW TO DO IT: Because, you never know, if you already have a new lambda with new wire colours, I cannot say which wire colour is correct in your existing lambda. But I know that before the first plug, you can see and find the correct earthing/grounding wire: There are four wires coming to that plug from ECU; out of one being BLACK. That black one is the earthing/ground. You need to connect an additional wire to that black wire and connect that to any adjacent bolt to have a good earthing.
 
Back
Top