Lacked power rough running when cold wrx

[Orangepeel]

Drove my 21 wrx to work today. I was running late so I hopped in and left it was 10 degrees. Started fine but when I got on the main road and got into the throttle it lacked power and ran rough. No engine light no codes nothing. I backed off and drove it easy and it was ok. Basically it did it when it would hit boost I think. Once it warmed up it was fine and happy. Does have a Cobb access port stage 1 93 octane tune. Not sure why it behaved this way. Any thoughts?

 

[Eddie]

Protecting itself against abuse?

 

[MParr]

What oil and viscosity do you have in it?

 

[KrisZ]

Partially frozen intercooler or turbo pipes?

 

[twX]

I would try to replicate it while taking some data logs.

 

[Orangepeel]

What oil and viscosity do you have in it?

Amsoil 0w30

 

[Orangepeel]

Protecting itself against abuse?

From driving it?

 

[Orangepeel]

Partially frozen intercooler or turbo pipes?

I wondered this. Is there an easy way to know?

 

[meep]

Probably not without manual inspection. Some eco boost owners drill a small hole in a low point in the intercooler to drain it - can be an issue in the cold or on humid/wet days. They complain of symptoms above freezing, however, not just in the cold.

 

[The_Eric]

As others have suggested, frozen intercooler or maybe an issue of not in closed loop operation not jiving with the tune?

 

[sloinker]

Subaru? Maybe the denser cold air has caused too much compression and the heads/head gaskets are shunting the excess pressure to atmosphere, thus causing drive-ability problems. This may foreshadow the 100k replacement engine maintenance interval. How many miles? LOL

 

[ElectroMechanoMan]

I think the EcoBoost problem was solved by Ford using a smaller charge air cooler. The early engine had so much cooling, moisture in the compressed air would condense and cause a miss by getting water in the cylinders. Your problem could be as simple as being a bit cold blooded. I wouldn’t worry about it too much if it only had a problem at low temperatures. I would let it warm up a couple minutes in cold temps, not more than 5 minutes.

 

[BobsArmory]

My wifes 2016 Malibu started running rough last week when it was really really cold, P0299 code popped up. Turbo charger underboost condition I think. First time it has happened on our car but I hear it can be common for small displacement turbocharged engines.

 

[bobdoo]

Could also be ice in muffler, if you short-trip it.

 

[Orangepeel]

So I hooked my scan tool to it today and found long term fuel trims at -15 so i removed the tune and went back to stock and had the same thing. So then I tuned it for Cobb stage 1 91 octane +sf v400 tune. Which is a map for their stage 1 with a redline intake. Once I did this the long term fuel trim is +3 and it runs great. Maf sensor readings from 2.8 grams per second to 2.3. I do have a Perrin cold air intake on the car which they claim doesn’t need a tune at all to run and they also claim that intake is fine with stage 1 91 octane Cobb tunes. I’m going to reach out to Perrin tomorrow and see if I can make some sense of this. On the current map it runs flawlessly and the data seems great so there’s that.
Crazy how picky Subarus are though

 

[KrisZ]

You never mentioned it was modified and tuned.
That’s quite an omission.
With aftermarket mods and tunes, these kinds of problems are not a surprise at all.

 

[RooflessVW]

IMO the tune isn't playing nice with whatever cold start routine you were in.

My VW has a "cold-cold" warmup routine when it is below freezing. Lots of EGR and even delayed shifting from the AT.

 

[TCL]

"Does have a Cobb access port stage 1 93 octane tune."

 

[KrisZ]

"Does have a Cobb access port stage 1 93 octane tune."

Missed it since it was basically a foot note.

The basic rule is if you modify something and it misbehaves, the modification should be the first thing to examine.

 

[Orangepeel]

You never mentioned it was modified and tuned.
That’s quite an omission.
With aftermarket mods and tunes, these kinds of problems are not a surprise at all.

It was mentioned in the very first post that started the thread………..I literally couldn’t have been any clearer!