Micra/March hr12de suddenly losing power

Greetings,

Signed up to this forum because i found a quite unique case/issue (at least, for me).
Mine is 2012 March with 1.2 NA (HR12DE) and RHD.

Recently, my car often lost its power suddenly after some 'spirited driving'. It was suddenly running so rough almost sounded like a steam train (the best way to describe its sound) and when that happen in idle, the whole car shaking and the rpm dropped so low that i thought it was going to shut off itself (but never happened, just a blink of battery light).

As i said it was a unique case because no engine check light or any warning light came on when that happened. And so far, pulling it over and shut the engine off for a while fixed the issue.

I believe the issue caused by either the ignition system or the fuel system, but i don't want to make a false guess and fix.

I recently also bought an OBD2 reader, just to gather more data record if that issue come up again (i did check for the fault from that but nothing came up. I think it was expected from engine check light not showing up).

Any suggestion or idea of the cause or where i should start looking from for this issue?

Thanks.
 

SplanK

Site Supporter
Could be a number of things really. I personally would initially focus on the coils/plugs as it sounds like it was missing. If it was fuel of bunged up exhaust, surely it would continue to run bad after a 'turn it off and on again'. MAF - again, i'm not sure it would run right straight after and usually it would default into a safe mode rather than showing missfire signs?

I suppose there is a chance that it could be an injector fault, however plug/coil is easier to try first!

Have you extracted and checked the plugs for damage? Fairly simple job and costs nothing other than a bit of time (and a removal tool if you dont have one). When were the plugs last changed? On my DIG-S, I replace every 35000 miles. Not sure what it is on the N/A version.

It could also be a coil that's on it way out. Worn plugs can cause the coils to run harder so if they have never been changed, and your enthusiastic driving could have just pushed one of the coils over its edge of happyness through heat. Turning it off and on again could have reset the coil, or given the coil just enough time to cool down a bit to restore functionality.

A way to check for this is if it happens again - pulling the connectors on the coil to disable that cylinder to see if makes any difference. If its only running on 2, and you pull another working one, its likely that the engine will stall, however if you pull a coil that isn't firing, nothing should change. IF you do identify a cylinder that isn't firing, I would then swap the coils between cylinders to either confirm its that coil (IE fault should follow), or if the ECU/wiring is bad to that cylinder. Although change the spark plugs first before going down that rabbit hole if they have not been done for a while.

Whilst no engine light came on, there may still be freeze frame information stored on the ECU. Not every issue flags the EML but may have a counter to say if it does it X number of times, then flag it up.
 
A choked exhaust or bad mass air flow sensor .

That's a bit far off from my expectation, but since this car is a bit off from its maintenance (used to be done by my parent) i think now everything's possible :ROFLMAO:

Could be a number of things really. I personally would initially focus on the coils/plugs as it sounds like it was missing. If it was fuel of bunged up exhaust, surely it would continue to run bad after a 'turn it off and on again'. MAF - again, i'm not sure it would run right straight after and usually it would default into a safe mode rather than showing missfire signs?

I suppose there is a chance that it could be an injector fault, however plug/coil is easier to try first!

Have you extracted and checked the plugs for damage? Fairly simple job and costs nothing other than a bit of time (and a removal tool if you dont have one). When were the plugs last changed? On my DIG-S, I replace every 35000 miles. Not sure what it is on the N/A version.

It could also be a coil that's on it way out. Worn plugs can cause the coils to run harder so if they have never been changed, and your enthusiastic driving could have just pushed one of the coils over its edge of happyness through heat. Turning it off and on again could have reset the coil, or given the coil just enough time to cool down a bit to restore functionality.

A way to check for this is if it happens again - pulling the connectors on the coil to disable that cylinder to see if makes any difference. If its only running on 2, and you pull another working one, its likely that the engine will stall, however if you pull a coil that isn't firing, nothing should change. IF you do identify a cylinder that isn't firing, I would then swap the coils between cylinders to either confirm its that coil (IE fault should follow), or if the ECU/wiring is bad to that cylinder. Although change the spark plugs first before going down that rabbit hole if they have not been done for a while.

Whilst no engine light came on, there may still be freeze frame information stored on the ECU. Not every issue flags the EML but may have a counter to say if it does it X number of times, then flag it up.

Ok, now i need to keep some screwdrivers to unplug those coils when that happens again. On my last maintenance in OEM repair shop, the guys said the plugs were OK eventhough it's been not replaced for a while and i asked them to address the misfiring problem. All they did just 'tune up' or cleaning the plugs and intake.

I could just replace all the plugs anyway, but the good/original coil cost something to me if i replace them all. So to find and replace only thing that went bad will be something i really appreciated at this times.

I will also check for the freeze frame information on my next drive and encounter. I am still figuring out how this OBD2 app works, i am using Nissan Data Scan III app. Please let me know if you have other OBD2 app suggestion that also worked on 1.2 NA engine.

Thanks for the insight. I will keep you guys updated.
 
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