Idle issues - please help

Ihtisham Rauf

Ihtisham Rauf

Car has slightly shaky idle.
When I started it this morning, it stalled itself pretty much immediately.
Then restarted and it was fine although shaky idle.

It idles around 600rpm when warm and when I blip the throttle, the revs go up (obviously) but then they drop back to to around 400 at which point the car stalls.

This doesn’t happen everytime; most of the times it just feels like it’s about to stall but doesn’t actually stall as the revs quickly build back up again.

Verdict?
Dirty MAF?

Actually last week, when I started the car, it started to rev itself to 2500rpm, then dropped back down to idle, then revved itself again to around 2000rpm, then dropped back down to idle and it did this around 3 more times before it went to a steady idle.

Appreciate any help as I start to go into a panic when it plays up.
 
Okay so it is the MAF as suspected but my mechanic told me that the only way to change MAF sensor is by changing the whole throttle body???
Surely this can't be correct? I mean its not a big or expensive job to change the throttle body for another stock one but I just don't think Nissan would have designed it in this way...
It would make sense just to get the sensor replaced right? But apparently he can't get to the sensor???
 
Ihtisham Rauf said:
Okay so it is the MAF as suspected but my mechanic told me that the only way to change MAF sensor is by changing the whole throttle body???
Surely this can't be correct? I mean its not a big or expensive job to change the throttle body for another stock one but I just don't think Nissan would have designed it in this way...
It would make sense just to get the sensor replaced right? But apparently he can't get to the sensor???
Click to expand...
Held in by two secure torex screws (coil pack) and remove and replace
Dizzy is a simple solder job

Sent from my moto g(6) using Micra Sports Club mobile app
 
Okay so I have ordered a new MAF.

But the problem got much worse yesterday with severe power loss sounding like it was on 3 cylinders and misfiring, and then sudden surges of power like the engine was suffocating. Checked all intake parts and they seemed fine.

Then checked the coilpacks and on cylinder 1, the coilpack and the area around the spark plug well had dirty water in it! No idea how that got into there. Put a vacuum cleaner on and sucked the water out and there's more power now than ever, so this is probably something that has been affecting performance for the past few weeks - maybe when I took the rocker cover off to paint it, I didn't seal it back onto the head properly? but then why only cylinder 1?

Going to keep a close eye on it for the next week or so.
 
At least on the dizzy engine maf can't be replaced with a change of a the tb, but it can be opened and resoldered. Normally this is enough.

Enviado do meu MI 8 através do Tapatalk
 
Ihtisham Rauf said:
Okay so I have ordered a new MAF.

But the problem got much worse yesterday with severe power loss sounding like it was on 3 cylinders and misfiring, and then sudden surges of power like the engine was suffocating. Checked all intake parts and they seemed fine.

Then checked the coilpacks and on cylinder 1, the coilpack and the area around the spark plug well had dirty water in it! No idea how that got into there. Put a vacuum cleaner on and sucked the water out and there's more power now than ever, so this is probably something that has been affecting performance for the past few weeks - maybe when I took the rocker cover off to paint it, I didn't seal it back onto the head properly? but then why only cylinder 1?

Going to keep a close eye on it for the next week or so.
Click to expand...
the seals down there are oil seals, so the only way water can get in is from above the coils
 
The power had all returned for one journey.

On my journey home, the car started to make a slightly rattly noise and there is SLIGHT power loss.

I reinspected the spark plug well and I was expecting a little bit of water but nothing, its completely dry. what could be causing the loss now?

The spark plug well for cylinder1 is quite filthy overall (the other spark plug wells are spotless).
I am thinking to change the spark plug for cylinder 1 but am unsure whether I should - when I remove the spark plug, all the dirt and particulates will go into the combustion chamber?

I'm thinking to get a hairdryer tomorrow and dry the area out of all water, if there is any water remaining.

Please advise people?!
 
Last edited:
I wouldn't be bothered by just water. I would remove coil cable and start the engine for a bit to flush water out. Then start it with spark. But that is just me. If someone chimes in telling me the way I tackle this has it's mishaps please tell me.

For the dirt I wouldn't be bothered easy eiher but it really and that is really really on what kind of dirt is inthere. Also, I wonder if a nice and clean vacuumcleaner would help to get the most out.

For the oher part, I'm curious to learn how to clean dirty spark plug shafts and I even would consider using a solvent. That won't lessen the dirt (besides it may be broken down to unharmful parts) but this might be rocket science. I think that if the dirt hasn't sanding properties or will stick to valve stem some wisely chosen, based on good thinking work will get you a long way. I even would do it this way without asking here.

I'm curious what happens now in this thread after this reply of me. It is good to have some basic remedies at hand and still decide this what you can do with little effort is sufficient, low risk and helps you to get to the following page which is probably some more ghetto solutions for a strong Nissan engine.
 
richardwbb said:
I wouldn't be bothered by just water. I would remove coil cable and start the engine for a bit to flush water out. Then start it with spark. But that is just me. If someone chimes in telling me the way I tackle this has it's mishaps please tell me.

For the dirt I wouldn't be bothered easy eiher but it really and that is really really on what kind of dirt is inthere. Also, I wonder if a nice and clean vacuumcleaner would help to get the most out.

For the oher part, I'm curious to learn how to clean dirty spark plug shafts and I even would consider using a solvent. That won't lessen the dirt (besides it may be broken down to unharmful parts) but this might be rocket science. I think that if the dirt hasn't sanding properties or will stick to valve stem some wisely chosen, based on good thinking work will get you a long way. I even would do it this way without asking here.

I'm curious what happens now in this thread after this reply of me. It is good to have some basic remedies at hand and still decide this what you can do with little effort is sufficient, low risk and helps you to get to the following page which is probably some more ghetto solutions for a strong Nissan engine.
Click to expand...

Appreciate the detailed answer!

I’m going to wrap a little bit of cloth onto end of screw driver and use it to clean the remaining sludgy dirt around the spark plug, and then also use vacuum cleaner and hair dryer to be sure.

Once I’m satisfied it’s clean, then I’ll remove spark plug to check its condition, and then also crank engine a few times without all 4 plugs in to push any remaining water out.

I am weary about using any solvent as I don’t know enough about this lol.

Thanks for taking the time to help!
 
Gave the cylinder 1 spark plug well a thorough clean again today using a vacuum cleaner, hair dryer and a bit of cloth wrapped around a long screwdriver.

Then checked the spark plug for cylinder 1 and it looks good, not cracked or oily etc. Car runs really well now, not misfiring at all anymore so well happy with this. I have ordered an MAF from eBay which should come within a few more days and so for now, I am running it with the MAF disconnected.

The only thing I noted was that there is a slight green residue on the spark plug electrode. The spark plug on cylinder 2 looked the same and I didn't bother checking the plugs for cylinder 3 and 4.

Green residue means an overly hot plug based on google?

unnamed.jpg
 
Last edited:
I put the new eBay MAF in today and the car ran terrible with it, very rough idle and stalls very easily at low speed, so I have no choice but to run with the MAF disconnected for now.

So as a word of warning to people, stay away from cheap eBay MAF sensors.

Its my understanding the sensors are really sensitive, and so wrapping it in bubble wrap may not have been the best choice.
 
Ihtisham Rauf said:
I put the new eBay MAF in today and the car ran terrible with it, very rough idle and stalls very easily at low speed, so I have no choice but to run with the MAF disconnected for now.

So as a word of warning to people, stay away from cheap eBay MAF sensors.

Its my understanding the sensors are really sensitive, and so wrapping it in bubble wrap may not have been the best choice.
Click to expand...
Tried disconnecting the idle control valve those can cause idle ect issues and contract cleaner.maybe on the MAF or somthing??

Sent from my moto g(6) using Micra Sports Club mobile app
 
I would reinstall old MAF if you are able to. It is dissapointing your new parts doesn't work but you can claim it with ebay.

For the spark plug colour I'm pretty surprised it is green. I can not find sites explaining green is heating. But I did find sites that say it is from leaded fuel :/

Here is a chart. You should check your plugs for correct grade and correct gap. Which brand do you have there?
bougies.jpg
 
richardwbb said:
I would reinstall old MAF if you are able to. It is dissapointing your new parts doesn't work but you can claim it with ebay.

For the spark plug colour I'm pretty surprised it is green. I can not find sites explaining green is heating. But I did find sites that say it is from leaded fuel :/

Here is a chart. You should check your plugs for correct grade and correct gap. Which brand do you have there?
bougies.jpg
Click to expand...

Yes before I put a claim in with eBay, I do just want to make sure it isn't the ECU needs relearning as Frank mentions.

No idea on spark plug gap. This engine was put in less than 4 months ago and apparently it was serviced in May 2019 by previous owner but never asked him on plug brand. As a rough guess, they will probably be NGK or Bosch, as these are the most common plug brands for Micra K11's.

Thanks for the chart, have saved onto my laptop for future use!
 
nissan boy said:
Bosch can be utter crap for running problems and I don't trust when they say it's been serviced most the time specially a cga

Sent from my moto g(6) using Micra Sports Club mobile app
Click to expand...

Hmm yeah I see what you mean, although I did get the oil and filter changed last month and my mechanic said judging by the oil, the car had indeed been freshly serviced but unsure whether service means plugs replaced as well!

I also did have a problem with a Bosch plug cracking on my CG10, will replace all plugs at some point in the new year as they seem fine (apart from the green deposits).
 
I'm not sure what the correct gap is for a CG engine but it might be 1.1 mm instead of the regular 0.9 mm. If someone could chime in here please?

For spark plugs, if you go to your preferred shop, they might have no NGK at stock. Just tell them you need NGK and if needed with the correct gap. Don't let them propose you a replacement, NGK copper is all you need. Cheap and easy to replace.

Besides spark plugs, the rotor is a often overseen but a cheap part that needs to be replaced for strong spark.
 
1.1 millimeter it is. Don't let them sell you 0.9 mm while you could adjust with a feeler gauge and if you happen to have a feeler gauge check the new spark plugs for correct gapping. And NGK it should be.

.Maarten, what is the source of this K11 Engine Tuning page 127?
 
Last edited:
.Maarten said:
I think its from service manual
Click to expand...

Really? Is it just me not being aware brown RTV is possible with Nissan and that service manuals can have a page with the page number not in the middle? I'm curious because such a list is a good start and what would be on page 1 to 126 and further might be even more interesting to squeeze out some performance like I like to do.
 
Okay so just a quick issue:

When under hard acceleration, the car seems to hesitate between 3000rpm to around 5500rpm as if its not getting enough fuel.

After disconnecting the 'new' ebay MAF, all the power comes back (but at the cost of the usual issues such as poor fuel economy and shaky idle).

So obviously the MAF is faulty. The MAF does its job well at low RPM i.e it gives a very steady idle and theres no jerking at low crawl speed but it doesnt work well at the higher revs.

Instead of buying another ebay MAF, I am thinking to clean this one, can anyone recommend me a cleaner? (dont want to buy some snake oil sort of thing).

Or I can go to scrappy and get a used MAF from a scrap K11 but want to try cleaner first.
 
scorpio said:
I got a good aftermarket MAf a year ago. I had similar problems to you for £21 and you can send it back if it is not the problem for a small restock fee.
The have a good reputation but I got it via ebay.

Click to expand...

I’ve put the old MAF back in. I also sprayed the MAF with electrical contact cleaner before putting it back on the car.

Idle is good, no power loss issues but engine light still came on after about 5 miles :/

Getting kinda fed up with this now.

Went to a few scrappies today to get a used MAF sensor but they all refused to sell me one individually, stating that I would have to buy the full throttle body.

Next step is to buy a full throttle body from scrappy or eBay for £40ish, just for the MAF sensor unfortunately.

Update - have managed to get a throttle body for £30.
Going to try to sell it on once I’ve taken the MAF off it (but obviously make it clear that I’ve removed MAF from it)
 
Last edited:
Well just the TPS and the AAC might be sellable. FICD is also important part but I don't think people look for it but it could break down. You might want to sell the AAC and FICD together. On the other hand if a throttle body without a MAF sells, that might be easier. People that look for a AAC really need one becaue theirs is messing up drivabillity. Next to MAF the AAC is the most valuable part.
 
richardwbb said:
Well just the TPS and the AAC might be sellable. FICD is also important part but I don't think people look for it but it could break down. You might want to sell the AAC and FICD together. On the other hand if a throttle body without a MAF sells, that might be easier. People that look for a AAC really need one becaue theirs is messing up drivabillity. Next to MAF the AAC is the most valuable part.
Click to expand...

Appreciate the info. Will put up various listings alongside one another and see what sells first.
 
Hurray received the second hand throttle body today and took the MAF from it and put into mine and finally all issues solved!

Have also refunded the ebay MAF, and the 'Holts Electrical Contact Cleaner' which just turned out to be snake oil as expected.
 
If you happen to have a chance to connect Datascan with it, the voltage of your MAF when engine not running is a good measure of how long it will last.

I don't think your contact cleaner is a snake oil. I've put it to the test with a worn MAF (drives good though) and because I know deposits on a MAF wire come from contact with a lot of air, degreasing should help. Internet says brake cleaner destroys a MAF. Maybe this can happen but not with the Nissan MAF that I tried to clean in several ways with agressive stuff I could come up with. It just doesn't help at all, voltage stayed 1 volt where 0.7 volts is considered being a mint MAF. But I could tell visually I cleaned that wire a bit.

A MAF heats a small wire and by reading it's current temperature, the computer believes how much air is passing. A lot of air passing will reduce it's temperature a bit more then less air so it's a figure the computer puts in to a calculation I don't know how that works exactly but this doesn't matter much since I can't change my computer. Maybe when I get to a point or have the opportunity to customize the computer this might become interesting.

The only reason I can think of a MAF wears out is that this wire will wear. For example, dust in air will sand something and that I what I think is happening to MAF's that usually go out after 100 - 150 kmiles. But if a given MAF shows 0.7 volts with engine off, you want to buy it ;)

If someone can explain to me why an engine with a worn MAF and or worn lambda is able to inject and burn more fuel but still give the same power output, please chime in!
 
thats the point of the self learn ecu,s on the coilpack engines, as the sensors go out of sync with age, the ecu compensates to a degree
hence the need to calibrate a new sensor when its fitted (pedal dance or reboot or whatever)
 
Yes, they asked for vin. One car i have other i don't. Original part number is also okay they said. If pricing is similar for other Nissan engines I'll probably buy from them.

What are long and short fuel trims, frank?
 
Last edited:
richardwbb said:
I wouldn't be bothered by just water. I would remove coil cable and start the engine for a bit to flush water out. Then start it with spark. But that is just me. If someone chimes in telling me the way I tackle this has it's mishaps please tell me.

For the dirt I wouldn't be bothered easy eiher but it really and that is really really on what kind of dirt is inthere. Also, I wonder if a nice and clean vacuumcleaner would help to get the most out.

For the oher part, I'm curious to learn how to clean dirty spark plug shafts and I even would consider using a solvent. That won't lessen the dirt (besides it may be broken down to unharmful parts) but this might be rocket science. I think that if the dirt hasn't sanding properties or will stick to valve stem some wisely chosen, based on good thinking work will get you a long way. I even would do it this way without asking here.

I'm curious what happens now in this thread after this reply of me. It is good to have some basic remedies at hand and still decide this what you can do with little effort is sufficient, low risk and helps you to get to the following page which is probably some more ghetto solutions for a strong Nissan engine.
Click to expand...
just a suggestion for cleaning out plug wells, cold engine so no risk of fire or burn, use solvent degreaser , cotton balls on stick and blow out loose particulate with air line , use eye protection,! Remove plug , it may be loose not sealing and water grease is condensate or fuel blow by,
 
Morphix said:
just a suggestion for cleaning out plug wells, cold engine so no risk of fire or burn, use solvent degreaser , cotton balls on stick and blow out loose particulate with air line , use eye protection,! Remove plug , it may be loose not sealing and water grease is condensate or fuel blow by,
Click to expand...

Genius, added to my toolchest!
 

Similar threads

skymera
Help, Idle issues :(
Replies
3
Views
1K
skymera
skymera
Ihtisham Rauf
Gearbox Issues - PLEASE OFFER ADVICE!
Replies
12
Views
1K
.Maarten
.Maarten
A
Idle issues
Replies
7
Views
2K
Alienfish360
A
R
new here guys, idle speed issues etc etc
Replies
2
Views
786
nissan boy
nissan boy
radarcomp
Weird engine idle
Replies
14
Views
2K
davyboy
davyboy
Back
Top