My car seems to be hitting a wall when I roll into it. When it starts to boost it's ok, but when it reaches 15psi it's like it's hitting a wall and just doesn't seem to pull anymore. Sometimes it clears out, but not all the time.

What do you think could be the problem?
thanks!

 

no cel? sounds like coil packs I think

 

No cel (if I keet getting on it when it happens it will throw a code), but this happens sometimes and I change my coils and it runs fine for a while then starts running bad and doing the same thing over again

 

What code came out of the CEL? It could be a lot of things - the code that tripped the CEL is important. Could be O2s, MAF, bad wastegate solenoid, FPR, DV, vacuum leak...

 

Usually only throws a misfire and it works fine for a while(after changing coil) then happens again.
Sometime it runs just fine and then bad again..
N75 maybe?

 

This could be irrelevant (but potentially related to misfire), but what plugs/gap are you running and how old are they?

 

Change plugs often and .028 I think

 

Not being a 1.8t guy, I could be misinformed with this statement, but its worth a shot.

How long has it been doing this? Did it just start when it started getting colder? If so, it could simply be fuel cuts due to the colder air; colder air is denser air and thus your air/fuel ratios are whacked. My buddy gets this same problem all through winter because the ECU is registering a large amount of air but the fuel pump/injectors can't supply enough fuel to match it so when you hit a certain boost level, the ECU cuts the fuel supply momentarily because you'd be running lean if it didn't so it forces you to not boost above the point that you're getting more air than the system can supply fuel for. But like I said, don't take my word for it since I'm far from being a reliable source of 1.8t info not being a 1.8t owner.

 

Yeah but it does it sometime and sometimes not. I guess I'll clean the MAF and maybe change back to the factory n75. With my upgrades what spring should I be running and should I have a shim in the DV? I really need to get new intercooler hoses! I have a post of new hoses from ebay, do you think they would be bad to use? Look upgraded like samco.

 

Drove it last night (about 30 degrees) and sit getting a bad studder when rolling into it. Sometimes it will clear up at higher rpms and start to pull hard and sometimes it doesn't. I also noticed that it back fires hard when I'm down shifting. It's like as soon as it gets close to 15psi it starts to act up. Any more suggestions?

Thank you