R32 Gtr Rb26 Very Very Soft/doughie/slow Pre-operating Temp?

[ohno1]

hey guys, something that i've been noticing recently is that driving my 32 GTR around before the water temp is at operating temp, the car runs like it has a heap of timing pulled out of it..

i only drive the thing once a week if that, so it's hard to remember if it always did it, or if it used to do it a little bit but it's more prevalent now or what the story is..

i'm not talking about lack of power at full revs or even on boost, but to even get the car moving upto traffic speed (ie.60-70kph) it seems to need an added 40% throttle and almost needing to get it onto boost ..then after 5minutes (once the needle on the water temp guage gets to 1/3 -- just below where operating temp would be) it's like the computer chucks in 8deg of timing and it picks up 40-50% more power magically

i've also notice that at pre-operating temp the car @ idle / clutch in, the vacuum/boost guage doesn't drop as much, then once upto proper temp the thing will go deeper into vac at idle

just wanna know what the story is, if it's normal or not

cheers

edit:

the car has stocky computer.. just has a pipe, intake pods, more boost.

also had to resolder the afm's a little while ago cos of the "surging" issue that i've read a few people have gotten

Edited January 28, 2010 by ohno1

[The Mafia]

Don't know if this is normal or not but I certainly don't let the car gain boost when it isn't at operating temperature.

Also, you shouldn't be looking at the temp guage, but the oil pressure. When the oil pressure drops, that means your oil is hot enough to drive the car around normally.

[R31Nismoid]

^ Agreed.

Apart from that... could be a myriad of things. Leaky gaskets perhaps that are sealing once warmer, faulty sensors (AFMs, temp sensor etc).

Even though you "fixed" the AFM doesn't mean its working 100%.

[STATUS]

sounds lean, possible the afm is screwy.

[Swiper the Fox]

sounds lean, possible the afm is screwy.

yeah...warm up enrichment issue perhaps.

[LotusGTR]

Trent, if you're watching this, this is also happening to my car. I'm very pleased to have found this thread as the description of what is happening is way better than what I would have come up with and is spot on. Almost exactly at the time I get full water temp, the 'niggle' disappears.

You may want to get it hooked up to the computer whilst cold and see what's happening at light throttle / low revs....

Ohno1, my car is getting some work done (including a tune) in a couple of week's time so if we un-earth the problem I'll let you know what it was.

[bubba]

Cold start..

Edited January 28, 2010 by bubba

[blind_elk]

If you only drive it once a week, it's probable the battery is on the way out. And Skylines in general are VERY susceptible to voltages. Because the alternator is busy recharging the battery following the start procedure, the ECU sees this increased amperage output as a potential problem, and can't run the engine properly.

Try keeping the battery on a trickle charge, at least for the 24 hours before you normally drive the car.

And for goodness sake, keep it off boost while the engine is still cold.

[turbovan]

maybe water temp sensor faulty, not getting cold enrichment or extra advance

[STATUS]

Trent, if you're watching this, this is also happening to my car. I'm very pleased to have found this thread as the description of what is happening is way better than what I would have come up with and is spot on. Almost exactly at the time I get full water temp, the 'niggle' disappears.

You may want to get it hooked up to the computer whilst cold and see what's happening at light throttle / low revs....

Ohno1, my car is getting some work done (including a tune) in a couple of week's time so if we un-earth the problem I'll let you know what it was.

no stress, i can monitor and adjust all these parameters once we fit the nistune board

[bubba]

Are you all sure it's NOT Cold Start?

My stock ECU would be in cold start until exactly 65deg (read from Datascan), as soon as the temp reached 65deg it would flick back onto normal maps.

[ohno1]

cheers for the replies..

i'm not "boosting" the car cold.. what i mean is that due to the reduction in power when cold i need an increased amount of throttle and revs to get the car upto speed (eg. 30% throttle in 1-2-3rd to get to traffic speed, bringing vacuum/boost to 0).. whereas once it's warm i can drive with traffic @ 20% throttle and keep it well into vacuum

ok i might see if i can borrow a pair of afm's or something see what i can sus out..

i'm waiting on a OBD port cable so i can check what parameters change when the water temp gets up but i figured i'd better ask in case it was something common/super obvious

LotusGTR -- thanks mate, appreciated

bubba -- when your car runs on the cold start map; is there a noticeable difference in power output until it puts the normal map in @ operating temp??

Edited January 29, 2010 by ohno1

[bubba]

Very noticable, and the changeover is also very noticable. The instant it hits 65deg you feel all the power/response come back. Pretty much feels like the engine is being choked/throttled big time until it's warm.

Edited January 29, 2010 by bubba

[ohno1]

ok thanks heaps for that..

i'll worry a bit less for now, but i'll keep everyone's input in mind.

probably chase up a pair of z32 afm's anyway in the very near future anyway

Edited January 30, 2010 by ohno1

[bubba]

Heh no probs, by all means make sure everything is A-OK!

I orginally thought I had the wrong heatrange plugs or something like that, did a lot of trouble shooting but the fact that it changed at exactly 65deg, everytime, without fail, made me look more at the ECU! (the benefits of a CarPC with Datascan running all the time ) You can actually "push" through it (not a good idea) which also made me originally thing something was stuffing up but it was exactly the same after going from the RB20 to the RB30 with a brand new z32 afm, brand new bigger injectors, new coils and harness and a remap.

I'm assuming the maps can be changed to be not as "harsh" but my tuner didn't see fit to do so when I got my remap and TBH, it's a good little reminder not to boot it when it's cold

[R31Nismoid]

ok thanks heaps for that..

i'll worry a bit less for now, but i'll keep everyone's input in mind.

probably chase up a pair of z32 afm's anyway in the very near future anyway

You want Nismo AFM's.

Z32's don't bolt on, Nismo AFM's do - and are almost identical to Z32 (minor difference in resolution).

Get them from perfectrun - they are the cheapest.