Average Idle Range For M35

[3PointJ]

Hey Guys,

Just wanted to know, when idling what are normal or avergae RPM's the car should be idling at?

I've noticed our one seems to idle quite, but not sure if it is normal or not.

Cheers.

[Ross]

Mine sits at 500-600 depending on engine temp

[PN-Mad]

650rpm + - 50rpm is normal. In neutral without electrical / ac load.

If anything else- advise cleaning the throttle body, and doing the idle reset procedure.

Oh, and tacho is generally not that accurate. Mine reads quite high compared to what the ECU sees via computer. Don't ask me why...

Edited April 15, 2012 by PN-Mad

[iamhe77]

VQ25det's are around 650 when warm although mine sat quite happily at 550 in summer.

Dunno about the 3.5's as I am still waiting for mine but I can't imagine they'd be much different to the V35 sedan idle (~650 as Alex said)

[PN-Mad]

same same. 650 +- 50 in the 3.5

[3PointJ]

Ok, we got the VQ35 and it's been idling around the 1500rpm (with a bit of fluctuation either side) mark. When you first start it up it revs up around 2000 then drops down...

Was kind concerned as to why it was idling so high.

I'm not much a mechanical hands on guy, specially in this car, but whats the best way to clean the throttle body? Also what's the procedure to reset the idle.

thanks for the help guys

[PN-Mad]

Re-post of a PM to another member.

http://forums.nicocl...ng-t356397.html

Points to note. Disconnect your batter before going to disconnect the TB. You'll see if its dirty. Mines held on by 4 allen key bolts. Some people say that the TB is coated in some special stuff to stop it fouling up, and this special coat is lost when you hit it with carb cleaner. I figure if you look at it and see its all fouled up, then that special stuff hasn't worked and you have to clean it anyway!

MOST important thing- dont move the plate one mm. don't touch scrub push etc etc the plate. just spray it and around it with brake cleaner / tb cleaner. It will be mostly black on the plenum side- this gunk makes it stick to the housing and prevents it correcting the idle properly.

Re-assemble everything and complete all the steps in the link. Sometimes you get it in one, sometimes it takes a lot of attempts to get the timing right. Your idle should self control- go high, then low and settle as per the insutrctions.

There has been people do this and not successfully re-set their idle, I think the TB was catus.

Have fun!

Anything to add?

Oh, 1500 is way to high. Its possible that it has been cleaned and not re-set to self learn idle.

Edited April 21, 2012 by PN-Mad

[scotty nm35]

Manifold leak. Check all the hoses and the gasket on the plenum.

[Daleo]

When I did mine; it was doing a couple of odd things.

When rolling to a stop or idling along in traffic; it would idle too high, and fight you on the brake until stationary. Then the idle would drop, but not to 650rpm.

When starting; it would do a funny little hiccup, as if the fuel pump hadn't primed properly; then the idle would settle; again not at 650rpm, normally a bit higher.

When I opened it up; I was quite disappointed. I expected it to be absolutely filthy, as most other people had discovered. Still, I flushed it clean, and I too lost the painted on coating at the sides of the throttle plate.

It obviously worked though; when I refitted it, I had no more histrionics or issues, and it definitely idled higher. A quick Idle re-learn; bang on 650rpm, everytime.

The coating is this stuff apparently; http://www.dowcorning.com/applications/search/default.aspx?R=740EN

[iamhe77]

Easiest way to clean it is to remove and then just spray using the little plastic nozzle included with this

http://www.nulon.com.au/products/Aerosols/Throttle_Body_and_Carby_Cleaner/#.T5SeW6uP_qc

I used it on the Magna's TB last week which had what looked like a chocolate mud cake on it.

Just sprayed (no wiping) and it all came off, was quite impressed actually. Then just soaked up any excess fluid with a rag, let dry for 10 mins, all done

[zei20l]

hmm when i cleaned mine i moved the butterfly plenty of times. didnt make a difference to running the car. i had to do the idle air volume learning again anyway and throttle reset etc

[scotty nm35]

Having pulled one apart, there isnt much damage you could do by opening the butterfly and cleaning it. It will rev higher due to being cleaned though and the idle would have to be reset. If the ecu cant get the idle below 700 it wont set it so if there are any leaks (pcv, manifold, hoses) it will stay at high idle.

[PN-Mad]

Iain, I know what you mean. I wouldn't have thought it made a difference either. However I have heard of plenty of stories of people who had cleaned it, moved it and had subsequent dramas (mostly G35s and the like). So I just took the safest route, which was not to move it at all. You have to use a bit more cleaner to do it that way, but I figure if it saves dramas, then its worth it. It's just my 2c.

[zei20l]

i think you just posted the reason. G35s in the US..........

[PN-Mad]

Well thats Me, and the OP are the same as G35s. Are yours NM35s different?

[iamhe77]

Nope, same TB

[zei20l]

i meant the stupid people in the US

people that probably shouldnt be touching or removing parts from their car

[PN-Mad]

i meant the stupid people in the US

people that probably shouldnt be touching or removing parts from their car

Oh, so 100% true.

If there is a was to #@!% it up, a yank will find a way....

Just imagine them all cleaning it with a wire brush...

[3PointJ]

Oh awesome. Thanks for the reply guys.

I shall suss it all out tomorrow and see how it goes. Might take it slow so I do it right. If anyone will f**k anything up I will lol...

So with that link to the Rest Procedure Alex, do I do all of the procedures? Just want to clarify

[PN-Mad]

yeah, run through all of them. I found it worked best when I did all of them.

I found it was far easier to take the whole top plenum off, and then remove the TB from that, but it might be a bit intimidating if your not into DIY. Any questions, just post them up.

Good luck mate.