M35 Still Stalling - Not Idling Properly

[pixel8r]

Hi,

My M35 has been having idle problems for about the last 3-4 months.

I've narrowed it down to a fairly specific case - and I can verify this almost every time now.

It generally idles at 500rpm - has done since I got the car (oct 2008). Occasionally it will idle at 650rpm as it should, but I find this is mostly when its cold. Once it warms up, the idle revs drop to 500rpm.

It actually idles very smooth at 500rpm most of the time, so I haven't worried too much about it.

However, if I rev it just a tiny bit then take my foot off the accelerator again straight away, it will splutter before coming back up to 500rpm. Sometimes it doesn't recover and just stalls at this point.

If I'm rolling along slowly and release the accelerator, and then turn the steering wheel, the extra load from the steering is usually enough to stall it. However it is not an issue with steering, because it will still splutter even when its stopped and/or when the steering is at the centre (ie. straight ahead).

Some other things about it:

* ONLY happens when the engine is warm. Seems more likely when the weather is hot too.

* Only happens when idling or revving below say 600rpm. When travelling anywhere over say 10-20km/h or with any pressure on the accelerator - it wont stall.

To my way of thinking it must be airflow related - ie. the engine being starved of air at the moment the throttle closes - (or almost closes?).

I've performed the Accelerator position learning, throttle closed position learning, and idle air volume learning and all seem ok except for the idle air volume one. Either it stalls straight away, or otherwise it pretends nothing is wrong but still insists on idling at 500rpm. Doesn't seem to be "learning" anything. very stubborn!!

No ecu fault codes come up when I check this either - its always 0000. Any ideas? Anything I can check?

Edited June 17, 2009 by pixel8r

[zei20l]

cleaned AFM? cleaned TB? i bet its choked up! checked to make sure your CAS has been changed (i believe andy had similar stalling problems due to this)

done the spark plugs too??

[Bis-e Bee]

Some of the other guys might tell you some more things to check but if all fails maybe going into a Nissan dealer and getting a 'Consult' check done would help.

It may reveal there is an airflow problem and they may be able to find the problem if there are error's logged on the ECU from the times it has stalled.

[pixel8r]

Some of the other guys might tell you some more things to check but if all fails maybe going into a Nissan dealer and getting a 'Consult' check done would help.

It may reveal there is an airflow problem and they may be able to find the problem if there are error's logged on the ECU from the times it has stalled.

Last time I had it in at Nissan they told me their consult software wouldn't talk to it. Whats the bet they were using Consult-I - which is what the s1 & s2 stageas use. When I went there they were expecting a s2 and they've worked on s1/s2's before. Is it possible they didn't click that VQ engine means Consult-II? I believe the M35 should use the same as all 2001 or later Nissans?

But again, I've checked the ecu fault codes via the manual diagnostic procedure, and it definitely flashes up the code 0000 via the engine light on the dash. I've checked this several times over the last few months, including right after its stalled. Still the same.

zei - I have cleaned the AFM several months ago - might pay to do it again? I only used metho last time (as its the only non-residual cleaner i had) but I might try some electrical contact cleaner on it.

How is the best way to go about cleaning the Throttle Body? I had the intake pipes off just recently and its mostly clean but there is a small layer of black around the edge of the throttle.

I dont think its spark plugs because its fine at high rpms etc. wouldn't it start to misfire if there was issues with plugs? Also a CAS fault would show up on the ecu fault readout for sure wouldn't it?

Some other theories I have are that maybe the AAC/IAC valve (whats it called? the bit that lets air through when the throttle is closed, so that it can idle) is blocked up a bit and not letting enough air through?

OR since it seems to be temperature related, maybe its some kind of temperature sensor? or maybe its just the fact that hot air is less dense so if its already not getting enough air, the hotter the air the more it struggles??

At this point I'm interested in anything I can do - like cleaning stuff, spraying contact cleaner on any connectors, checking any sensors with a multimeter? or things along those lines.

If I cant solve it this way, then I'll need to book it in to Nissan.

Edited June 17, 2009 by pixel8r

[zei20l]

ok as far as i can tell there is no AAC/IAC valve. being that the throttle is controlled by the computer, thus it doesnt need the other valve

i took my TB off the car completely (be VERY careful with the gasket) and cleaned the shit out of it. carby/tb cleaner is probably the best stuff. be careful of the motor, i didnt remove that from the assembly. i was just careful not to get it too wet.

while all thats off, pull a plug out and check it anyway. youll need to take off half the piping to get the TB off anyway, so pulling a plug out wont be much trouble while youre there

[iamhe77]

Is there someone nearby that would be willing to do a quick swap and trial of parts for an afternoon?

Try the AFM first (quick and easy - just unbolt from the airbox and loosen the intake tube), if no difference work your way back to the plenum (BOV, throttle body etc).

[pixel8r]

Is there someone nearby that would be willing to do a quick swap and trial of parts for an afternoon?

Try the AFM first (quick and easy - just unbolt from the airbox and loosen the intake tube), if no difference work your way back to the plenum (BOV, throttle body etc).

I'll try the AFM first and will see what happens. I might also check the BOV since this may be blocked up - which I believe would cause the same issue?

Thanks heaps for the help guys, its given me some things to try.

[zei20l]

no worries. yes a blocked BOV MAY cause this problem....... but to me i dont see how.... but that doesnt mean dont check it!

[loymclure]

Few people suffered this with their s1's and s2's. I had the same problem i changed my airflow meter, got new plugs gapped at 0.8 any i also insulated my coilpacks from the engine this seemed to stop the problem for a little while but then it came back. So i dont know if it was the same problem or a different one with the same symptoms. any way it turned out to be a split pipe that ran accross the top of my engine. One thing you can try is a bucket of soapy water run your hand over any air pipes if you hear a hissing sound could be a split pipe - reason its getting worse is the pipe could be splitting more. Im not saying this is the problem but it sounds similar to the problem i had with my s1 a little while ago. i know its a different engine but its worth a look.

[pixel8r]

I think I found the problem.

Here's some pics of the Throttle Body:

Front

Back

You can see even on the Front side the ring of black thats built up. On the Back its quite evident there is a LOT of build-up. So much that it was blocking the intake off completely, and maybe stopping the throttle from moving freely from/to the closed position. I believe this was also contributing to some lag and also the occasional sudden jolt when moving off from a standing start.

Anyway so I cleaned it all up - sorry I didn't take any AFTER shots - would've been a good comparison though - basically it turns out the inside of the pipe is actually grey/silver - who would've thought? I also cleaned the inside of the other pipe (the part that the TB attaches to - is that part of the plenum?) so hopefully it'll be a while before it returns to the state it was in...at least I know how its all done now - although it didn't take long to do.

I cleaned the AFM as well, gave it a thorough squirt with contact cleaner and left it to dry while I did all the above stuff...

Checked the BOV - nothing unusual there - all good.

Then I did all the diagnostic stuff again, accelerator pedal position, throttle closed position, and also idle air volume learning. As an aside - obviously the idle air learning works - because when i turned the car on for the first time after it was all back together, it was revving at like 1500rpm!! Thats how much difference cleaning the TB makes!

All that was needed then was a good cruise round the block for about 10 minutes to get it all properly warmed up, then do the diag stuff all over again - i've got it all memorised by now...

This time it didn't stall on the idle air learning procedure - it just started up at 1500rpm and slowly dropped the revs until it hit exactly 650rpm and then stayed there. The manual says to rev it a couple of times and make sure the revs drop back to the same spot - which they did, no spluttering at all!

On one occasion as I was cruising around it idled at 600rpm but never below that. A couple of slight taps on the accelerator and no problems at all. Before if it was idling and I just tapped the accelerator lightly, the revs would go up then drop out and nearly stall.

Looks like its problem solved. You guys are the best! I think it was like the 2nd suggestion and zei's reply was like 2 minutes after I posted.

[zei20l]

how do you perform the learning procedure?

how many ks were on your car? i cleaned my TB at around 90k and it was filthy like yours. mine wasnt stalling however. next step im gonna remove all the intake manifold and give that a thorough clean out.

and youre welcome! thats what this forum is for!

[pixel8r]

Here's all of the diagnostic procedures I'm aware of for the ECU (there's more for the A/T too) - its all in the V35/G35 manual which I'm sure you have a copy of - its available on the net otherwise if anyone wants a copy just pm me (I'll need an email address - its a ~60MB download so you'll at least need broadband internet). The G35 is sold in america so its all in english (phew).

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. (EDIT: if you lift the bonnet and try this while you're outside the car - you'll hear a sort of click/scrape sound coming from the throttle body - it does this sound pretty much every time you turn the car off -you probably just never noticed before).

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 each time electric throttle control actuator or ECM is replaced, or if 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 Degrees C (158 – 212 Degrees F)

- PNP switch: ON (Park/Neutral Position Safety Switch - AT only, MT fully depress clutch)

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

- Steering wheel: Neutral (Straight-ahead position)

- Vehicle speed: Stopped

- Transmission: Warmed-up (For A/T models, drive vehicle for 10 minutes.)

Operation Procedure:

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. - (EDIT: THIS IS IMPORTANT - i've tried it when the car is cold and it will likely adjust the idle incorrectly so that when the car warms up it will idle too low).

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:

7a. Fully depress the accelerator pedal.

7b. 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:

Idle speed A/T: 650rpm, + or - 50 rpm (in P or N position)

Idle speed M/T: 650rpm, + or - 50 rpm (in N position)

Ignition timing A/T: 15 Degrees BTDC, + or – 5 Degrees BTDC (in P or N position)

Ignition timing M/T: 15 Degrees BTDC, + or – 5 Degrees BTDC (in N position)

13. If idle speed and ignition timing are not within the specification, Idle Air Volume Learning will not be carried out successfully. If idle speed and ignition timing are within the specification and Idle Air Volume Learning cannot be performed successfully, find the cause of the incident by referring to the following Diagnostic Procedure:

1. Check that throttle valve is fully closed.

2. Check PCV valve operation.

3. Check that downstream of throttle valve is free from air leakage.

4. When the above three items check out OK, engine component parts and their installation condition are questionable.

5. If any of the following conditions occur after the engine has started, eliminate the cause of the incident and perform Idle Air Volume Learning all over again:

- Engine stalls.

- Erroneous idle.

Edited June 17, 2009 by pixel8r

[pixel8r]

how do you perform the learning procedure?

how many ks were on your car? i cleaned my TB at around 90k and it was filthy like yours. mine wasnt stalling however. next step im gonna remove all the intake manifold and give that a thorough clean out.

and youre welcome! thats what this forum is for!

My car has done 96500km now. The idle/stalling issue was the only problem I was finding with it...so now it should be running like new!! I was suspecting wheel bearings earlier but that turned out to be really extreme tyre noise. Never buy FIRENZA ST08's!! They were great for about 2 months then they start to get real noisy (due to really fine ripples in the tread pattern - makes a noise very much like those "audible lines" on the sides of the road out in country areas - except its all the time and not quite that loud).

I've said a lot of nasty things about my M35 - I now take it all back. Its a fantastic car - much better than my last stagea! There I said it

[zei20l]

hahah he has seen the light!! we all told you they are awesome

thanks for the insructions! ill try them at some stage soon

did you pull a plug out too while it was all off? what wsa the condition?

[pixel8r]

hahah he has seen the light!! we all told you they are awesome

thanks for the insructions! ill try them at some stage soon

did you pull a plug out too while it was all off? what wsa the condition?

Nah didn't touch those. Didn't get that far into it. They're due to be changed soon anyway, 100,000km service coming up possibly end of this year. I'm gonna assume they weren't changed during compliance and get them done then.

[zei20l]

ohh shit no they werent done during compliance lol

they would have actually had to have done some work! i guess yours was done by Shogun?

[iamhe77]

ohh shit no they werent done during compliance lol

they would have actually had to have done some work! i guess yours was done by Shogun?

Why not!

Northshore do 'em.

Glad the car is nice and pretty again Steve!

Should clean my throttle body as well, would need it no doubt.

Anyone here cleaned the black FMIC piping and if so, what did you use?

Edited June 17, 2009 by iamhe77

[pixel8r]

ohh shit no they werent done during compliance lol

they would have actually had to have done some work! i guess yours was done by Shogun?

No mine was done by a business here in brisbane. I've been warned once for speaking my mind on here so I really dont want to comment too much. Its really nothing more than misundertanding and miscommunication that turned ugly. I have no complaints about the quality of the work that was carried out. I dont feel that I got my money's worth but I dont know enough about what was done to offer a fair and balanced comment. Its just hard parting with so much money when you cant visibly see what its paying for (I physically saw, touched and sat in the car BEFORE compliance). Had I bought the car from a local dealer it wouldn't have mattered, but I know what I paid for the car in Japan, and I paid more for compliance (incl all parts, tyres etc) than I did for the car itself.

But yes generally speaking I do feel that compliance companies charge an enormous amount of money for what _appears_ to be a simple job that any mechanic could do in a day or two. Obviously there is a lot of organisational headache that goes on behind the scenes as well, on top of the mechanical work - and I believe this is why they charge so much.

[zei20l]

haha got ya, no i only commented because some key things were lacking in the compliance of my car..... like an oil change for example...

[andy65b]

Glad to hear that you problem is now sorted.

My car was doing similar things. The only mistake I did was had 2 things done at once. TB cleaned and TPS reset. I don't know which solved the problem but my car idles a bit fast at around 775 - 825.

I wish I could get it down. I might do the TB clean this weekend if I get a chance.

The inlaws are visiting over the weekend this sounds like a great reason to be working on the car. LOL