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Hey guys

Went for a cruise around tonight and even after the car had warmed up it was still acting like it was in cold start.

As I was driving along at 60km throttle in exact same position the car would go limp and feel gluggy then would free itself back up.

The feeling is similar to towing a trailer and then not towing one it just swaps between this randomly under 3k rpm it also sometimes had a slight jolting feeling like what I believe a miss feels like.

But when above 3k it doesn't do it at all.

I have had this issue with the cold start pulling timing below 3k rpm and Jez is going to rectify this next time I see him.

The water temp stayed at where it normally does so I just don't understand it.

I just purchased new spark plugs, diff oil and gearbox oil so that's all happening tomorrow

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It was 1am in Canberra so probably close to -4 or something. Can't say I have driven that late at night before on this tune actually.

So it must be to do with the outside temp being to low to let the car warm up? Does the Ecu temp sender go off oil temp or water temp

My Neo has been taking absolute f**king ages to get all the way warmed up, just driving around in Adelaide 7°C morning temperatures. Idle revs are staying up over 800 for ages (like 20 minutes of stop start morning traffic) and the revs flare up to 1400 as you clutch in rolling to traffic lights. That sort of shenanigans. I can imagine it would be even more annoying if I was in sub zero temps.

I keep intending to hook the laptop up to it before starting the drive to work to see what the coolant temperature is actually doing in that time. The thermostat really should let it warm up properly....given that in warmer weather it warms up very quickly indeed. But I'm prepared to believe that there is something wrong with the thermostat, or possibly the cold start AAC needs a bit of carby cleaner to make it move more freely. The other possibility is that the coolant channel in the cold start AAC valve is a bit blocked up (like it was when I first got the motor) and needs to be cleaned to make sure that it gets warm.

Probably should have said I unplugged the AAC

Because it kept f**king with my revs

No matter how I adjusted it the revs stayed at like 1300-1500 all the time even when warm.

Also used to idle and miss constantly.

Now it's unplugged I get perfect 800-1000rpm all the time no missing on idle

If your ECU has the ability to set/tune Engine Temp compensation and/or Air temp comp id say they havnt been set/adjusted and because you've not run the car in such low ambient temps the issue hasnt surfaced till now. Should be a relatively easy fix.

It was 1am in Canberra so probably close to -4 or something. Can't say I have driven that late at night before on this tune actually.

So it must be to do with the outside temp being to low to let the car warm up? Does the Ecu temp sender go off oil temp or water temp

ecu gets temp from water, 2 pin sensor at front of intake man, prob red on r33, cold air maybe making it run a bit lean??

As GTSBoy said, from what you have said I'd be looking at:

AAC valve

Thermostat

Coolant channel in the cold start valve.

Sounds alot like the problem is temperature dependent!

IMO easiest for me to work on is the AAC valve. Hook it back up and see what it does in similar ambient temperatures. If its still carrying on, take it off, give it a clean (I believe there is a Tutorial on how to clean it properly), re-install, connect it back up and re-evaluate.

If its still carrying on, then take the thermostat out and check its function via heating/boiling some water on a stove. Check its movement as the water gradually gets hotter and hotter (to a point where it will stop moving). Or you could do it like these blokes do on youtube

Lastly, I'd be checking the coolant channels to the cold start valve. This is due to accessibility issues, but it will depend on your intake setup etc.

Originally, I was getting my motor pulling timing (not to your extent where its like cold start) via the knock sensors. My sensors would falsely detect knock, pull timing accordingly and the car would feel all sluggish etc. I doubt that this is your issue, but something to keep in mind. The fix was to take the ECU to Pete at NIStune to disable the knock sensors in the ECU itself.

Edited by R32Abuser

Thanks guys

I checke the thermostat and it opened up in a pot of hot water so that's good.

Tonight I'll go for a cruise and test it with and without the AAC plugged in.

I have cleaned the AAC before but will do it again to make sure it's all good.

I will get back to you with updates

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