M35 Surging During Warm Up & More Power

[danwatt]

Hi Guys,

I have noticed that during warm up and under very light throttle (no boost) the car wants to surge and has trouble holding a constant rev.

I have also notice that there is considerably more power during warm up that when at operating temperature.

Any Ideas ?

I was thinking it might be something to do with AFM and the air intake temperature sensor. As we all know that performance is reduced in hotter temperatures.

[Jetwreck]

Hi Guys,

I have noticed that during warm up and under very light throttle (no boost) the car wants to surge and has trouble holding a constant rev.

I have also notice that there is considerably more power during warm up that when at operating temperature.

Any Ideas ?

I was thinking it might be something to do with AFM and the air intake temperature sensor. As we all know that performance is reduced in hotter temperatures.

yeh mine does the surging thing as well.....did it with the standard turbo to. Don't know about the more power when cold thing....mine goes like a piece of shit when its cold.

[zei20l]

yeah mine does it too. i have a theory, i rekon its something to do with the TPS being old/dirty. one day (when i find it) ill clean it with some contact spray and lubricate it.

apparently SOME V35s had TPS failures, maybe M35s suffer a similar problem?

[danwatt]

I find it has consuderable more power though which is a little anoying. I also find that once the ambient temperature is over 17 degrees power drops off. So there must be something going on

[zei20l]

well, cooler air is more dense, so it compresses better. i find mine doesnt go AS well above about 26. saturday night i was giving it a hard time with a mate and it was hauling ass but it was around 16 degrees outside.

maybe the intake temp sensor is faulty?

take it to a nissan dealer and ask them to check it. or run the diagnostics thingo yourself with the key/throttle combo trick

[Daleo]

I've also noticed the surging when cold thing, thought it was just me... No extra power though.

[iamhe77]

I find it has consuderable more power though which is a little anoying. I also find that once the ambient temperature is over 17 degrees power drops off. So there must be something going on

The default richer fuel mapping when cold coupled with cooler denser air would give you more power I would think.

Is your AFM clean? Could be a minor issue.

Definitely have a look at the intake Temp sensor, sometimes those plugs can come loose.

Have you removed your front bar and checked your intercooler fins? I know that I had an area that was bent to fark, no good for cooling the charged air.

(out of left field) Maybe install a voltage stabilizer such as the Hot InaZma? May help settle things down.

[danwatt]

The default richer fuel mapping when cold coupled with cooler denser air would give you more power I would think.

Is your AFM clean? Could be a minor issue.

Definitely have a look at the intake Temp sensor, sometimes those plugs can come loose.

Have you removed your front bar and checked your intercooler fins? I know that I had an area that was bent to fark, no good for cooling the charged air.

(out of left field) Maybe install a voltage stabilizer such as the Hot InaZma? May help settle things down.

Thanks, Front bar was removed not long ago and everything is clean. I might build a beat shield around the AFM to see if it is engine ambient heat heating the sensor and Ill see if this makes a difference.

[cussco]

Yeah + 1 for the cold surge, as i am an engineer i know the mechanical issues with flogging a cold engine and the inherrent damage it does so i can not comment on the extra HP when cold.