R32 gtst sluggsh when cold

[Guest Jordy32]

hi guys, just wondering if any one has had this problem with there rb20 at all & if so whats wrong???

when the engine is cold, for the first 5mins or so of driving the engine seems to bog down for a little bit then cleans up, only noticable when driving. feels like someone keeps shoving thier foot up my exhaust. it does this on & off for about 5mins of driving. when its warmed up its fine. whats the story????

dont know if its a oxygen sensor or water temp sensor, cause it seems to be only when the engine is warning up??

any ideas???

thanx guys.

[MicK51]

mine does the same thing, i think its in the tune. When u have a custom tune for more power it tends to stuff around with the other maps ie cold start and run maps.

[Squizz]

Mine does it too...

[crooser]

think you'll find its just overfuelling... mine even backfires sometimes during gear. changes only when its cold.

up to around 80deg the factory ecu dumps more fuel to burn in an attemp to get the temp up asap.

most aftermarket ecus let you control the amount of cold enrichment

[32ANA]

yeah ours backfires too! hehhee sounds kinda cute tho

[mindflux]

mine back fires every now and then .. i just think its due to the 98 octane..

as for it running slugish, i dont knwo becaus ei keep it off boost for the first 5 mins .. and also so diff is a bit weird so yeah

[Ronin]

Mine is the same, welcome to the club

[R32-Drifter]

I think most turbo cars are slugish for the 1st five mins, notice when it hits boost ad 2500 or so rpm its a suddern jerk?...cold!

hmmm you guys talk about backfires as if they are rare? mine sounds like a shotgun? and i can make it do it all the time "when the car is very warm" just by playing with accelorator....perhaps somthing is wrong with my car??? lol. isnt it just excess fuel igniting in the exhaust?

[32ANA]

did a real loud one last nite on the espy!!! louder than eva!!! (must have had baked beans for dinner!)

[MM2death]

stop back firing. get some fuel economy.

[bretto]

yeah just turbo cars in general, my old vl turbo used to do it to, wasnt surprised when the skyline did it as well.

[Cubes]

Its got a little to do with age.

When I first got my car it didn't do it.

Then one day it started.. I also noticed a slight flat spot even when warn putting around car parks. Its only really really minor though. Unless u were as picky as myself you probably wouldn't even pick it.

This topic has been covered to death. Do a search

[GTRgeoff]

Hi all

I think you'll find that as soon as someone plays with extra boost, they'll knock off a few degrees of advance. Makes it feel real sluggish, especially cold, but you can run more boost safely for more top end power. I fiddle with mine almost daily and the difference pre-boost is very noticable. I try to get the advance up just enough to be drivable, without onset of detonation on boost. Kinda walkin the tightrope but i need lower end response, not top end.

[Cubes]

Remember Its only when the car is cold skylinegeoff.

I'm running just over 20degree's timing with 1.1bar of boost on the rb20t turbo.

Bigger fuel pump so things are overfueling a little hence why i am able to run more boost and timing without detonation. Hits fuel cut on cool nights at the moment. May have to knock boost back a little for the cooler weather that is coming up.

The flat spot is only on moderate acceleration. Hence the chances are its got some thing to do with the 02 sensor's preheat is farked.

When the car was warm I was suprised how much acceleration it took for the O2 sensor to stop flashing (ecu O2 sensor diag mode). As soon as boost starts to build the O2 sensor stops flashing though.

My Vl used to do it also (230,000kays). Probably a nissan thing when things get old.

It doesn't bother me that much as I've started getting my self in the routine of warming the car up for a few minutes (new engine = forgy's = cold = cracked piston)

[GTRgeoff]

Yeah I was talking about cold.

So which forgies cracked when cold?

[Cubes]

All forgy's.

Reason being is they need to be brought up to operating temp before you give it a bit of stick, this is because they slop around in the bore when cold. I have heard that the material they are made of is weaker at cooler temps but I don't know how reliable that source is.

Any engine rebuilder will tell you to drive it really easy if you do drive the car when cold. Basicall until oil temp is up to operating temp, NOT water temp.

[GTRgeoff]

Naturally enough, you must always resist the urge to sink the locally built crap until up to temperature. After spending almost 5K on parts and machining I'm not too keen to kill this one quickly, even if I did do all the labour myself and picked up most of the stuff cheap.

I'm lucky enough to have chosen Arias and suffer no slap or rattle at all, but still find that I suffer sluggishness when cold if I overdo the retard of timing. Feels like driving through sand then if it starts to come onto boost it picks up. Might also have something to do with the 7 heat range copper plugs I run as well at 0.8mm. Oil pressure is sensational when cold too at over 8 bar on the guage so it is fairly safe to drive gently almost immediately. I like to look after my neighbors so long idle warmups are not acceptable with a big exhaust. As soon as pressure is well up I drive away.

I'm only relying on many years of experience as a mechanic and mechanical engineer, and have no real history with extreme race engines with lives of 2000km like the V8's even though I have briefly worked for one team. My understanding of the material properties of low silicon forged pistons if they are not as "tough" as factory cast high silicons, so they would be susceptible to shocks such as temp shock and pulse shock. Haven't checked the S/N curves to see what the transition temperature would be though. might be interesting.

I also wouldn't call myself an expert on Skylines as i only have the one manual and one auto, and really only work on my own cars now that I don't import anything, but I do experiment a fair bit and that playing with settings on the standard engine management has just revealed to me that timing is usually the big issue. Many are happy to sacrifice driveability for top end. I need good driveability for both road and racetrack.

It sounds like it could be a problem with your sensor, but thay do take a while to come up to temperature, might be on the way out, just not quite there yet. Are you running a rising rate fuel reg? I'd expect you are. What about computer and injectors? I'm certainly no expert on what a PFC should run like either...yet. Soon though I'll take the plunge after I'm satisfied with the run in of this engine. I run a GTR fuel pump that has delivered 316rwkw on an RB20 but experience no change in overfuelling or bogdown/flatness due to that. I also have the Malpassi fitted but turned way down until the PFC is fitted for tuning. I also have a Rigoli modified turbo that is slower to come on boost but does so at 4000rpm like a sledgehammer, highlighting the low rpm/cold sluggishness. Might be time soon to upgrade that. I think the auto's turb is going due to a little smoke in the mornings...took a while to confirm, so I might have a rebuild with rollers and wheels and put the rigoli in the auto, then have the rebuild in my car

Also the RB30 ran something like 7:1 (is that right or was it 7.5?) CR so even with the extra capacity they would be doughy due to the poor fuel quality they were designed for and the low boost/lack of decent intercooler. But once again, I'm no expert.

I hope more opinions are forthcoming, maybe even give more insight on the timing issue.

[RedDrifter]

Mine does the cold thing too.

Not many R32's don't do it from what I have seen.

[drifto]

I had a mate borrow the car and thought the hand brake was locked on.

I leave each morning and don't take it passed 2500 in 4th until i feel the funny kick. Something must get to correct temp and change timing and fuel settings to suit then she runs fine.

[red17]

Mine does it too, oddly enough it only started doing it after I got the engine fixed from burning 2 exhaust valves in cylinder 6. I know for a fact my 02 sensor is dead as a doornail. Could be that maybe.

I just put up with it, make sure i keep off the loud pedal until the needle is in the middle of the guage (where it normally sits).

Red17