R32 Skyline Cold Start Weird Issue!

[Kris..]

Hey guys,

I've just recently got into getting myself an r32 from having a few sr20s

My rb20det, standard except a exhaust. Has a weird issue on cold start that I cannot work out.

In mornings, the car will crank over, idle and become to warm up. But when I start to drive the car from 0-2000rpm it feels like it's hitting a wall until passed 2k then will drive perfectly fine. Now the weird part is if I even drive 3 houses down. Turn the car off and back on. Even though its still cold. It won't hesitate at all and drove perfectly fine.

I've done fault code tests to only come up with 55, I've cleaned the afm. Changed plugs, cleaned out coilpacs, I haven't yet had a chance to fiddle with the AAC unit just yet.

I figured it might be an ecu issue and by turning on and off the car it was resetting the cold start. But I have since swapped out the ecu for a working one off a friend with no change.

Anyone had this issue or can anyone enlighten me on it being something to do with AAC valve?

Thanks!

[Rekin]

Car runs rich until water temps hit 65degrees. This hesitation disappears when the water temp setpoint is met.

I have heard stories similar to yours in that you can turn off/on to over-ride the cold start fuel map but when I gave it a shot it made no difference for me...

Not sure if that helps.

[Kris..]

I bought the car with water pump replaced. It takes forever to warm up. I may try driving it from cold and install my after market gauge and see if that is correct.

Cheers for the reply

[Rekin]

I bought the car with water pump replaced. It takes forever to warm up. I may try driving it from cold and install my after market gauge and see if that is correct.

Cheers for the reply

sounds like thermostat is stuffed if car takes forever to warm up. Means the car would always be running rich. Check that out.

[DVS JEZ]

Rb20's pull timing when cold.

Does it feel like a rubber band effect, like its pulling back on the car until 3000 then releases?

[Kris..]

Yes DVs jet ! Exactly what feels like!

[Kris..]

I just drove it today. As I hardly drove it. Hasn't been started in couple days, it's a nice warm 27 degree day. Stated and idled perfect, drove it, does the rubber band effect till I turn the car off an then back on. Then it drives fine?

I also let the car warm up while it was doing the hesitation and it didn't change. Only until I turned it off and then back on straight away.

[Kris..]

Anyone!?