R33 Gtr Responds Very Poorly When Engine Is Cold.

[grant80]

Hi guys, im having an issue with my R33 GTR whereby when i start the car up and the engine temperature is cool (car not driven for 3+ hours) when i accelerate there is a distinct stuttering - almost like there is some kind of fuel starvation going on. This only happens when the engine temperature is cold. Once i drive it for about 2 minutes and it warms up it responds perfectly. It has been doing this for months and is not getting better or worse. I have performed a full service recently and cant figure out why it may be doing this. I have also noticed that the oil pressure readouts are especially high during this period and am wondering if a) when the engine detects it is cold it runs in some sort of pretective mode so the engine isnt damamged in the warm up period or b) something is indeed wrong. Does anyone have any ideas what this is?

Cheers

Grant.

[mad082]

where the spark plugs changed at the service? also do you know what heat range they are, what gap they are and how old they are? it may simply be a case of fould plugs. they are fouling when the car is cold and running richer due to cold start enrichment, but as the car leans out a bit when it heats up, as well as more heat in the cylinders then it is able to burn the fuel better.

[grant80]

where the spark plugs changed at the service? also do you know what heat range they are, what gap they are and how old they are? it may simply be a case of fould plugs. they are fouling when the car is cold and running richer due to cold start enrichment, but as the car leans out a bit when it heats up, as well as more heat in the cylinders then it is able to burn the fuel better.

Yes the spark plugs were changed about 3 weeks ago down at unique auto sports. Not sure what heat range they are or gap either. I am running a Mines ECU which i've been told is one of the worst controllers for australian fuel + climate. Perhaps this is having an effect as well?

[Victory]

Skyines and GTR's in particular run differently while the engine is cold to protect the engine. As soon as the ECU detects normal temps and oil pressure then they run in normal mode and should perform properly.

I normally just let my cars idle until I get water temps up and oil pressure down and then they respond normally and it does not hurt the engine.

[pistol-pete]

mine does this too, i just take it easy for 5-10 mins

[GTR-N1]

I thought MINES ECUs were tuned to Japanese 100RON fuel and non-programmable?

http://www.skylinesaustralia.com/forums/Mi...amp;pid=4976694

Yes, and as Charles said, warmups are essential.

I take it that what you're saying is, the car is even more temperamental since the plugs were changed?

If so, check the gaps and reduce if necessary.

[grant80]

Thanks for all your replies guys. I checked the service sheet from when the plugs were replaced and copper 6 heat range plugs were put in. I don't know enough about spark plugs to make a call on how they will affect performance when cold / hot but hopefully that makes more sense to you guys..

[mad082]

yeah range 6 copper plugs should be fine. if they were 7's or 8's (colder plugs) then they would be more prone to fouling when cold.