Need help. Going crazy.

[A4_B_Fizzy]

So a few weeks back I posted on here about wondering if I had a boost leak because I was only boosting 7lbs. After a lot of feedback and research it turns out my aeb engine was not having any boost leak. But it was running very healthy at 7lbs with peaks around 9. Now about 5 days ago check engine light came on and at the same time car would not go past 2lbs of boost. The codes were cylinder 3 missfire and evap code. Well it turned out that spark plug for cylinder 3 was broken. And I found that the evap check valve was burned. After replacing all plugs and evap check valve car is running the same. It's such a hog I don't know how to explain it.... I have a buddy who has a geo metro. We raced just as a benchmark and he took me off the line and threw 3rd gear. Once I hit about 45 in 3rd gear I started to slowly gain on him. It's like 1st-3rd gear no matter what rpm I'm in if I floor it all u hear is the intake get throatier and loud but no increase in speed. Is this more than just a boost leak? Btw. I did a boost leak test and it would not hold boost at all but I couldn't actually pinpoint were the boost leak was coming from. Leading me to believe its watergate actuator. But what I'm worried about is even if my turbo wasn't working at all would the car be this slow? I can't even merge into traffic without cutting someone off? Maybe I need to change coil packs? Idk just really frustrated. And don't know what to do.

[Weehe]

If you know you have a boost leak, you need to fix it. How did you do the boost leak test? Also, doing a boost leak test can't diagnose a bad wastegate. Did you reset the check engine light after fixing stuff, or is the check engine light still on? could still be in limp mode.

[fed0ra]

Btw. I did a boost leak test and it would not hold boost at all but I couldn't actually pinpoint were the boost leak was coming from. Leading me to believe its watergate actuator. But what I'm worried about is even if my turbo wasn't working at all would the car be this slow? I can't even merge into traffic without cutting someone off? Maybe I need to change coil packs? Idk just really frustrated. And don't know what to do.

What leads you to believe its a bad wastegate actuator? If it won't hold boost during the leak test then you have a major boost leak that can damage your motor and/or turbo. When you have a leak that big your turbo doesn't just stop, it works harder to reach the requested boost, so running your car like this and effing racing it will only cause premature failure of something important. Stop driving it and figure out where your leak is.

Well it turned out that spark plug for cylinder 3 was broken.

Broken? As in the electrode broke off into motor? Have you checked for damage? If it broke off into the motor then you could have ruined your motor, especially by driving it at all, let alone racing it. If it broke on the stem and nothing got into your motor then you need to be asking yourself "why the hell did my spark plug split in half?".

[A4_B_Fizzy]

Hey guys. Got off from work today and car is running perfect again. No boost leaks. I hit about 8psi and it held it all through 4th. Gear. Any ideas what would make my car run shitty and not boost properly and then just fix itself after about a week? FYI I did seafoam through brake booster 2 days ago... Maybe it was all clogged up??? Not sure. But as of now car is running great. Weird...

[walky_talky20]

Yeah. If you didn't clear all the codes after fixing it.

It won't reset itself out of limp mode (2 psi) until it sees something like thirty (30) drive cycles (that's you, driving your butt to somewhere and shutting the key off) in a row without the original problem reoccurring. So it finally did that after a week and gave you the boost back. Not really weird or surprising.

[A4_B_Fizzy]

Thanks for the input. Didn't know that. Saved me the trouble of wondering if it was going start up in limp mode one of these days

[pichno]

Yeah. If you didn't clear all the codes after fixing it.

It won't reset itself out of limp mode (2 psi) until it sees something like thirty (30) drive cycles (that's you, driving your butt to somewhere and shutting the key off) in a row without the original problem reoccurring. So it finally did that after a week and gave you the boost back. Not really weird or surprising.

I'm confused with the situation I ran into on the way to work tonight. I was accelerating softly due to running slightly lean, and trying to avoid boost spiked/WOT until Thursday when I can get a MBC installed. In 4th gear around 50mph at part throttle, the gauge was showing the typical up and down boost between 10-20psi during acceleration, I felt the car lightly jerk, then all of all sudden I couldn't get past 3-5psi no matter if it were WOT or not. I continued just cruising for 20-30 seconds in 5th gear and hit the gas again, boom my power/boost was back. The same situation happened a second time one stop light later, but this time in 5th gear without going WOT and not even boosting past 20psi, more like 10-15psi. Again, wouldn't boost past 3-5psi for a minute or so, continued crusing for a minute then randomly gave it gas again and then the power/boost was back. In the past, when this happens I'm unable to get my boost/power back until I turn off the car and disconnect the battery. Really weird. Other times when this has happened (once or twice) it took place when boosting high at WOT when the overboost happenes starting occurring upon the K04/5BAR install.

I'm trying to determing whether the smoke test is the best way to check for boost leaks. I'm currently searching for feedback on here and the Zine, but GIAC today told me on the B5's the smoke test doesn't work well, thus he suggested pushing at least 18psi into the lines for an accurate test. I've already checked the N75 duty cycle on Vag-Com which was good, MAF replaced, TIP replaced, and initial check for boost leaks was negative. My mechanic checked the N75 to wastegate line, and one other one leading to/from the N75 from what I can remember, but he just picked up the smoke test kit and will test again on Thursday when the MBC, upgraded FP, and new clutch will get installed. I'm also trying to have the fuel filter replaced because the vehicle has 251K on it and the FP/Filter are both stock. He has worked on Audi's/VW's for over 20 years and rarely has had to replace the filter, and also said the job sucks because of the partial tank drop, but I'm going to see if he's willing to do it anyway.