Boost problems

[Ybr_fr3d]

I’ve got a 2000 Audi a4 1.8t. I’ve got a stage 2 tune I just changed my turbo to a k04 because I had the head off because I was changing it instead of doing valves did the timing. The car runs fine when at like 5 pounds but 6 psi and up the car feels like the turbos surging. As soon as my car builds to 6 psi and up it starts bucking kinda and surging. I’m not sure if I’m running out of fuel Or something else I’m a little lost any ideas?

[rzyao]

I'd say start looking for boost leaks, then move onto fueling if you're absolutely sure there are no leaks

[Ybr_fr3d]

After getting on it, it throws a misfire code while building boost and after

[Ybr_fr3d]

What would you say is the simplest way to test for boost leaks? I’m almost certain there isn’t a boost leak but there could be one

[rzyao]

After getting on it, it throws a misfire code while building boost and after

If you're misfiring, maybe you have a bad coil pack. Try moving it around and seeing if the cylinder that the misfire is detected in follows where you moved the coil to, as the code should say which cylinder is misfiring. That's how I diagnosed a bad coil on my car

[rzyao]

What would you say is the simplest way to test for boost leaks? I’m almost certain there isn’t a boost leak but there could be one

For around $10 you can build one with a cheap soldering iron from harbor freight, an empty pickle jar, and some tubing. I'd suggest looking up a guide to making one, and it could come in handy in the future as well. You should see smoke pouring out of any major leaks that might be hard to find otherwise

[Ybr_fr3d]

I’ve got old coil packs in it right now I had a misfire problem now it don’t misfire except certain occasions. When I hammer on it start building boost it send a misfire code. And second when the cars completely cold it starts fine but if you give it too much gas while cold it starts misfiring and usually will stall like it floods over or something. Which is what points me towards fuel

[Cybersombosis]

You are running into fuel problems with your stage 2 tune. You can downgrade your tune to a stock tune and run your K04 but it won’t run properly with a higher flowing turbo with higher boost. Get a custom tune from Motoza. Sell your stage 2 ECU and that will help pay for a replacement stock ECU and a custom tune.