Too Much Boost - K04

[dubenvy]

Need Help figuring this one out because i have tried everything and i am stumped. I should also preface that i do not have a VagCom for logging

Car is K04 with APR and is boosting waaaaaaay too much. Pretty much i have to let the gas off to keep the needle on the boost gauge from going 360*. It already did once and blew some vacuum hoses. (which were found an repaired) Car had an N75 C which i pulled and replaced with an E from the dealer thinking the C was defective. They both behave the same. No regulation.

Checked the lines to the waste gate and found two leaks, replaced the entire line.....no change.

Drove around with the N75 unplugged to see if the waste gate was stuck and that was not the issue either. Wastegate regulated the boost and it would not go passed 6\7psi.

Drove with the MAF unplugged.....also no change.

Changed the APR chip to stock....no change.

I have not changed the MAP or the Coolant Temp, but i have new ones just in case. Does the ECU need to be reset perhaps?

[ShogunR32]

If you got a manual boost controller, Try running the MBC parallel to the n75 and see if that helps.

[dubenvy]

don't have one, but might get one this weekend. Have mixed emotions if it will work given all the other stuff that i have tried.

[FORCE_FED_DUB]

I've seen this problem before on APR tuned 1.8Ts running their K04 software. The MBC in parallel will help and will in fact open the wastegate at your specification. You can also "uncrank" the wastegate a bit to smooth out the boost spike.

[A4SoftWalker]

Clarify... This is happening with APR K04 Software???

There is a difference.

When I went with my K04 it I knew it would overboost till I got the tune upgraded for $200 to K04 and I stayed out of it after 20psi.

[dubenvy]

yup...this is APR KO4 software. No matter what program i put it in (stock, 91, or 93) the car always behaves the same. I guess i will try and find an MBC this weekend.

[dubenvy]

I've seen this problem before on APR tuned 1.8Ts running their K04 software. The MBC in parallel will help and will in fact open the wastegate at your specification. You can also "uncrank" the wastegate a bit to smooth out the boost spike.

How do you uncrank the wastegate?

[ECS Tuning-Audi]

Can you swap ECU's with someone to confirm its the programing and not something else?

Jason

[widgget]

if the MBC works it's just a band aid, the root cause will still be present.

[Charles.waite]

Too much boost? I wish I had this problem...

[dubenvy]

Too much boost? I wish I had this problem...

Trust me....it's not as fun as it sounds unless you have a built engine and a turbo that is supposed to boost that much

[dubenvy]

Can you swap ECU's with someone to confirm its the programing and not something else?

Jason

nope. Taking it to RAI tomorrow so they can have a look around through because my patience is spent and my knuckles are bleeding from pulling my n75 so many times.

[old guy]

Sounds like a software problem. Especially since unplugging the N75 resulted in a 6/7 PSI maximum boost. If it was a waste-gate problem unplugging the N75 wouldn't have cut the boost to the waste-gate spring pressure. Good luck tomorrow!

[dubenvy]

Sounds like a software problem. Especially since unplugging the N75 resulted in a 6/7 PSI maximum boost. If it was a waste-gate problem unplugging the N75 wouldn't have cut the boost to the waste-gate spring pressure. Good luck tomorrow!

stumped old guy.....not a good sign.

If it is, i may need to wait because it's APR and NGP was booked up. I'm hoping there is a boost leak somewhere that they can find. Tonight on the way home, it seemed to behave normally through 2nd gear. Matted it and it didn't get above 15psi. Once i get into 3rd through 6th, it will just boost whatever it wants. Annoying.

[old guy]

Have you logged your N75 duty cycle against your specified boost and actual boost? That may give you a little insight on what the ECM is requesting versus what you are actually getting.

[A4Maine-iac]

^ Listen to OG. My 1st K04 software had similar issue. (not APR) No boost leaks. Was boosting about 25+. Had the tune re-done and spike was gone. The fact that you are not going into limp mode kinda says that might be the issue. B4 you start dumping $ have them re-tune it. Might be the MAP sensor. Sorry did you mention this was right after software upgrade?

[dubenvy]

^ Listen to OG. My 1st K04 software had similar issue. (not APR) No boost leaks. Was boosting about 25+. Had the tune re-done and spike was gone. The fact that you are not going into limp mode kinda says that might be the issue. B4 you start dumping $ have them re-tune it. Might be the MAP sensor. Sorry did you mention this was right after software upgrade?

Ive thought about getting it reflashed as well, but it may have to wait. I have a MAP sensor that i can put in. may as well at this point right!

[dubenvy]

Put the new map in. No change.

[MikTip]

Disconnect ya battery and let the ecu reset

[boy412]

I have a spare ECU if you want to borrow it. Hope to see you @ RAI. I should be there @ noon.

[dubenvy]

I have a spare ECU if you want to borrow it. Hope to see you @ RAI. I should be there @ noon.

My car is there, but I won't be until 4. It's the silver USP

[fast4cl]

this happened to me after me first flash. i went back and told them the problem and after a reflash with the same software everything was normal. have u tried a n75 race? that was the only way i could boost up to 25 psi.

[dubenvy]

so today i found the air box is hacked to pieces on the bottom and the filter is probably from a B5 because it doesn't fit in there property. Got it in there tight for now until i can borrow Arclight's air box tomorrow. Not much of a change. Lower gears are behaving better, but 4 though 6 still pull 25+ PSI.

What about the N249? Could that be the cuprit? Going to check the connections on it tomorrow, but i am really stumped on what this could be.

Going to get the car reflashed too, but NGP is booked up so i need to wait a while.

[FORCE_FED_DUB]

How do you uncrank the wastegate?

Loosen the nut on the wastegate arm, effectively keeping the wastegate slightly open. Not my first choice, but it did work on a GLI with K04 and APR tune that had a nasty habit of spiking past 30psi and holding 29-30 when it was supposed to run 22-24psi

[n7plus1]

damn...this sucks. subscribed.

[boy412]

What about the N249? Could that be the cuprit? Going to check the connections on it tomorrow, but i am really stumped on what this could be.

Easy enough to bypass it for testing purposes.

[dubenvy]

picked up a loaner air box too. add some restriction to the turbo to see if the hacked air box and improper air filter are causing the turbo to spool faster than the boost regulation valves can cope. (thanks Arclight)

[FORCE_FED_DUB]

What about the N249? Could that be the cuprit? Going to check the connections on it tomorrow, but i am really stumped on what this could be.

N249 should not be causing this issue. The N75 in controlling the wastegate and not allowing it to open. The N249 SHOULD be opening the DV due to an overboost condition, but the software has disabled both the N75's ability to properly operate the wastegate and the N249's ability to vent an overboost condition. Both not great safety features to be without.

[dubenvy]

put the new air box in and it's much smoother, but still not completely right. Still surging a bit. The air box is keeping the turbo from spooling up so fast. Unfortunately, the car won't idle with the MAF plugged in now. Going to clean it and reset the ECU tomorrow. Its running fine with the MAF unplugged so i will just drive like that for tomorrow and will deal with the MAF tomorrow.

[boy412]

Did you ever figure out what's going on with your car? Curious about this one...

[dubenvy]

Nope. The tip was loose but all that did was smooth it out. I can still hit 25+