R32 Cold Morning Issue Help!

[r324drr]

Hi if i have put this in the wrong section pls move it.

Here goes i have a problem with my r32 gtst on a cold morning the car has no power it will boost fine but the revs are very slow to pick up and it kinda has a knock when i change out of first gear (gearbox is fine). at the same distance and when the car is warm it drives perfect. only happens when car is cold?

maybe o2 sensor, fuel pump?

only engine mods are: full hks exhaust

de cat pipe

pod filter

split fire coil packs

front mount intercooler

any suggestions would be great thanks?

[Moodles2]

What grade oil do you run (10w-40, 15w-40, 20w-50 etc)? it might just be a simple thing of running an oil that has more favorable cold viscosity than the oil you use now (and guessing during summer as well)

[The Dan]

Test the coolant temp sensor and test and clean the AFM

Coolant temp sensor should be around 3Kohms when stone cold and approx 300ohms when hot. If the sensor is faulty it will not be adding enough fuel for the cold start settings in the ECU.

[r324drr]

Test the coolant temp sensor and test and clean the AFM

Coolant temp sensor should be around 3Kohms when stone cold and approx 300ohms when hot. If the sensor is faulty it will not be adding enough fuel for the cold start settings in the ECU.

hey thanks for the reply's

i am running 15w oil and have used 20w. have cleaned the afm but not tested it yet

where abouts is the coolant temp sensor located? (im new to skylines)

[Moodles2]

Grab the PDF service manuals for the R32, will be a great help: http://www.importworkshop.com/nissanskyline.html

[blind_elk]

i am running 15w oil and have used 20w.

That's too heavy for a Skyline engine. And that is only the cold start viscosity - what is the other number?

A word of advice - DO NOT boost a cold engine. Wait until it has a bit of temperature.

IT'S NOT THE F****N O2 SENSOR!!!!!!!!!!!!!!!!

It's unlikely to be the water temp sensor - usually, when they fail, they don't tell the engine that it's up to temp, so the ECU overfuels the engine. Not a problem if the engine is still cold.

It's probably just that the ECU can't cope with the extra density of the colder winter air.

[The Dan]

That's too heavy for a Skyline engine. And that is only the cold start viscosity - what is the other number?

A word of advice - DO NOT boost a cold engine. Wait until it has a bit of temperature.

IT'S NOT THE F****N O2 SENSOR!!!!!!!!!!!!!!!!

It's unlikely to be the water temp sensor - usually, when they fail, they don't tell the engine that it's up to temp, so the ECU overfuels the engine. Not a problem if the engine is still cold.

It's probably just that the ECU can't cope with the extra density of the colder winter air.

15w~ is not too heavy for an RB20.

And the coolant temp sensor is highly likely considering it pretty much handles the entire enrighment map by itself while the engine is warming up. They can fail the other way and the engine thinks it's warm so it doesn't add the fuel it needs for cold start.

Why would the ECU not be able to cope with the extra density of the colder winter air? No one else has any problems....or does he live in antarctica? That's what the AFM is for, it measures air temp and flow. It will compensate when the air is more dense or less dense.