Revs At Startup

[Deep Dish V35]

just wondering how high other peoples engines rev when the car is first cold started?

mine currently revs up to 2000 before settling at idle... it has gradually been getting higher over the past year to this point.

not sure if its normal...

[Seano350GT]

Around 2k mark, when warm about 600-700

[sonicii]

Same as Sean, sometimes peaks at over 2000rpm on cold mornings, but only for a second, then quickly drops back to about 1500rpm, then drops slowly until the engine is warm, then sits on 600.

[Seano350GT]

yeah when i park at my girlfriends place outside i get up at 6am and when i start it sometimes goes over 2000

[Deep Dish V35]

hmmmmmm

was hoping people would say i was the odd one out.

for the first 6 months my engine never went over 1400 at startup. 2000 just sounds too high

[sonicii]

not sure why it does it.. the VQ35 in other cars doesn't rev that high.. but it does seem normal for the V35.

[Seano350GT]

One thing i have noticed though when i park my car over night outside and i drive in the morning, the engine sounds a lot better cold than warm (normal) but it feels a little bit gutless until it's warm but that just may be because i have it overnight 12 hours or so in 10ish degree cold.

[V35_Paul]

you might need an oil change? how long until your next?

or one of your O2 sensors might be faulty/dirty.

or it's really cold

[t5iv]

He's in Mackay... It doesn't get cold.

[Seano350GT]

you might need an oil change? how long until your next?

or one of your O2 sensors might be faulty/dirty.

or it's really cold

Flushed and changed my oil last weekend, o2 sensors are fine checked those a few weeks ago too.

He's in Mackay... It doesn't get cold.

Not true man! 2 weeks ago it hit 4 degrees here at night/morning

[iamhe77]

not sure why it does it.. the VQ35 in other cars doesn't rev that high.. but it does seem normal for the V35.

My Stagea revs to about 2400 for a second from first start in the morning and then drops as it warms up. Always has.

Damn thing won't drop below 750 when warm...

[sonicii]

have you done the idle air volume learn procedure?

After cleaning my throttle body, it wouldn't idle much below 900 until I ran this process.

I guess the VQ35 in the Stagea is probably setup the same. The VQ35 in the Murano and Maxima don't rev anywhere near as high at cold startup.. not sure why our cars need to?? I know they are tuned differently, but I am not sure why that would make a difference.

[Deep Dish V35]

i remember my startup revs situation started happening after installing the 350z intake tube. did both the throttle learn and idle air volume procedures multiple times with no improvement. there are absolutely no leaks anywhere.

its something i want to fix before installing the plenum spacer.

[iamhe77]

have you done the idle air volume learn procedure?

After cleaning my throttle body, it wouldn't idle much below 900 until I ran this process.

I guess the VQ35 in the Stagea is probably setup the same. The VQ35 in the Murano and Maxima don't rev anywhere near as high at cold startup.. not sure why our cars need to?? I know they are tuned differently, but I am not sure why that would make a difference.

I did indeed. Prior to the relearn, it liked idling at 950rpm when warm.

Far cry from my old VQ25det Stagea that idled at 550 when warm.

[Commsman]

Damn thing won't drop below 750 when warm...

I have a cable (+ laptop) & can set the idle to whatever I like (within reason). I should send it down to you one day; if no one in Melbourne has one you can borrow.

Edited July 31, 2012 by Commsman

[iamhe77]

You mean Cipher Leon?

Can only increase target idle rpm, not decrease it (I have a Cipher as well - used it to log the improved efficiency of the cooling system after the cooling mod)

Edited July 31, 2012 by iamhe77

[adzr33]

I'm far from an expert on any of this but is it possible that the vq35 in our cars reacts differently than other models due to being released for the Japanese market? It gets extremely cold there so maybe it is required for that climate??

[GTRsean]

Usually, and don't quote me on this they will rev higher on startup to heat up cat coverters quicker for emissions reasons.

A mate's 350ZHR did the same thing.

[sonicii]

Usually, and don't quote me on this they will rev higher on startup to heat up cat coverters quicker for emissions reasons.

A mate's 350ZHR did the same thing.

I would say this probably isn't the reason, the revs only peak to 2000rpm for a second then drop back to about 1500rpm, which is where most cars idle when cold. If the intention was to heat the cats and O2 sensors, it would need to stay at high rpm for much longer.

[Marshan]

Cold start revs to about 1500 then drops to around 600 mark when warm, mines never idled above 2k. Is it cold where you are?