Cold Engine

[stingray]

Hi

I've already tried a search, I vaguely remember a post similar but I can't find it. Anyway this is for an R32 gts-t. When my engine is cold it doesn't rev smoothly and it jerks a bit as the revs climb to 3000rpm. This is just driving normally and slowly, I haven't tried revving it passed 4000, obviously because the engine is cold. The mechanic has put in OWS 10w30 TXI TURBO LL SYNTHETIC oil. In the manual is says 7.5w30 is recommended, could this have anything to do with the cold viscosity rating of the oil I'm using?

Also when you start your engine, does you oil light stay on for half to one second? I've notice this happening all the time and I just assumed it's normal when starting up as it's building up pressure.

Thankyou

[MerlinTheHapyPig]

anything below 15 as a cold weight, is ok for turbo's

10 as cold weight is fine though i'd use a higher hot weight -- especially since it's an older engine. (also, there are climate differences between here and japan)

I've had good results in rb20det with motul turbolight 4100 (10w40), and a lot of people use mobil1 which is 5w50 from memory.

Yes oil light will come on for a second or two, as long as it doesn't stay on, or come on while you're driving. Also the factory oil pressure gauge is sometimes a bit dodgy, consider aftermarket.

not really sure about your problem, but it may not be oil related.

[bombastic]

I've noticed the same think happening in my R33 gts-t. Seems to happen between 2000-3000rpm, but once its warm its gone.

I figured the clutch must be on the way out... it seems the rev's increase, but there is less acceleration, and then it starts pulling again after a certain rpm's...

Sorry to dig up an old thread, but I'm wondering if anyone else wants to have a crack at this?

Edited May 29, 2006 by bombastic

[SLIPPERY]

i would say its due to the cold fuel maps in the ecu being a little rich when the water temp is still cold. when the engine is warm the fuel map looks a lot different to what it did when it was cold. ie, a more suitable AFR so that better combustion takes place and you dont get that excess of fuel creating the jerks and stuttering.

my standard ecu on my 32 GTR had a terrible cold start (same as what you described earlier)....changed it to a power FC and the standard cold start map suited the car a lot better and was smoother.

[BHDave]

It's something that seems to creep up on r32 gtst's with age. Mine never did it, and then one day i realised it had a few little flat spots when cold, and about a year later it was worse, and felt as if i wasn't applying constant pressure on the accelerator (even though i was). It stopped above 4k too, which lead me to beleive it was to do with the closed loop control and the cold start not liking each other very much. Possibly o2 sensor related?

I'd be interested to see what it is, as i never solved it myself (it wasn't my major headache at the time). I just dropped an rb25 in instead and it solved all my problems

[002doc]

Mine does this too and remembering a past thread, I think its normal in r32's, just dont drive hard until its at operating temperature which is common sense for all cars.

Cheers

[Husky33]

yeah mine does this also, feels a bit of a pain in the arse to drive when it's cold, but as soon as it's warmed up it instantly becomes all smooth and easy to drive. I'll check my fuel maps when my laptop and nisscan software arrive

[blackprincegts]

Iv got 2 r32's, both of them do it. My bro's CA18ET does it, and all my mates with rb20's do it too.

Iv often felt it might be the AAC valve or o2 sensor when they get a bit dodgy and old.

Mine stop doing it normally after 2 or 3 mins. I dont go above 3g annyway when cold.

[Driver]

Iv got 2 r32's, both of them do it. My bro's CA18ET does it, and all my mates with rb20's do it too.

Iv often felt it might be the AAC valve or o2 sensor when they get a bit dodgy and old.

Mine stop doing it normally after 2 or 3 mins. I dont go above 3g annyway when cold.

i got a pfc and all those problems went away

[SLIPPERY]

pfc fixes it as driver said

wont be o2 sensor cause you wont be in closed loop when the car is cold and accelerating/ changing gear all the time

[bombastic]

Thanks for filling me in! I'll probably get a pfc when I have some disposable income... I'm too poor at the moment to spend money on it

[R33S2]

On my RB25 I have rich band from 1200 to 3000 rpm, when the air intake temp is below 5*, if I keep it above 3000 it's fine and it still idles well, only when the engine temp is below 60* that is, if I feather the throttle enough I can get to run smooth. It will burble upto 3g and clear, although I hate staying in that rev range with a cold motor its not for long as my tuner (Peter Woodward) tuned the microtech for cold start, but the temps were above these and so is doing a remap next thursday, I will let you know the result friday.

Does this sound similar to your problem or completely different?

It seems to me that it is an inherent problem with these rb motors even without the ecu.