what are the symptoms?

car is an S4 TII, ALL STOCK.

WOT in high RPM's in 3rd and 3/4 throttle + in 4th at higher RPM's it has happened.

Basically car is going along fine then bam, zero horsepower, boost on the stock boost gauge drops from the gauge nearly pegged at +40, to -20. if you stay in it the car will maintain RPM for a few seconds and then the boost gauge will go back to full, then drop again.



it's been years since I've had a car with stock EMS so I kinda forget what happens - just making sure that this is fuel cut before I drop the turbo and port the wastegate. this car is totally stock and the owner wants to keep it that way so I just want to be sure.

 

That's what it sounds like, but it's usually after intake & exhaust mods that it starts happening. Of course, super cold weather could play a role.

 

My exp with fuel cut is that you will kiss the steering wheel. Meaning the car all of sudden stops and you end up leaning forward.

 

does the factory boost gauge drop to -20mmhg (or whatever the equiv is in the american cars, the very bottom line in vacuum, where it rests with the car off) when you hit fuel cut?

 

The few times I have hit fuel cut I couldn't notice it. IT just happend BOOM. Now if you were trying to hit fuelcut and you were looking then maybe you could notice. Which would be a bad idea.

Have you ported your wastegate? If not you might as well.

 

so nobody knows?

I read through the owners manual and it didn't even mention it.

I'll hook a real boost gauge up to it today and see where it says it's at.

 

IF you are hitting fuel cut then it is not good for the engine. Your next try could = BOOM. Then we can help you in your rebuild thread.

My advice is: If you haven't ported the wastegate then do that and see if it fixes the problem. Never hurts to port the wastegate as it lets you move on to other mods.

 

car is going to stay completely stock.

Fuel cut has never killed an engine, ever, AFIAK. it's not hard on the motor, it doesn't kill things, it's how the factory rev limiter even functions.


I pulled the turbo off, ported the WG a ton (especially behind the WG to help flow).

we'll see if it solved the problem tomorrow I guess once I have it all back together.