Losing power at WOT

[Seerlah]

Starting maybe 2 days ago, I noticed this. If I go WOT, the power drops off at ~4500 RPM. I plan on taking it to my mechanic tommorow, but if any can help me out to fix it myself that would be great. The turbo is fine as I hear it spooling well and my guage reads ~22psi. Yet, that power is not making it back to my drivetrain. Where should I be looking for a loose hose, cracked part, etc?

If I am partial throttle, there is no issue. But if my foot is to the ground, then there is an issue. If I am maybe 3/4 throttle, I can reach 7000RPM and have smoothe power all the way through. But if I go WOT, there feels as if the power is just being spewed into the atmosphere once I reach ~4500RPM, but the power is still there. Just not reaching the engine and the RPMs still climb as if (not as if, that is what it is) the power from the turbo is not being redistributed back into the engine. Where should I start looking?

Thanks!

[1fstavant]

when your on it wot is your boost consistantly at 22 or does it say drop to like 5 or something around those lines

[Seerlah]

Consistent at ~22psi and will not drop as the pressurised air is not being used. It stays at ~22psi and the turbo just spools expecting to build up more pressure. But if I am part throttle, it is all good. Only at WOT and 4500RPM or so is when the car feels like acting the little b*tch.

[redflagquattro]

my 01 does the same exact thing, id love to know why

[1fstavant]

honestly id let a mechanic look at it if it wasnt hitting the right boost i may have had a solution but since the boost is right i have no clue...

[Seerlah]

Just did a scan with my VAG com and no intermittent codes and I have no CEL. But to redflagquattro, I will take my car to the mechanic tommorow to see what is the issue. So check back and I will post what he says/does to remedy the situation.

Anyone else have suggestions before I take my car to the mechanic?

[biketsai]

Im sort of having similar problems, but on a different setup. My ecu closes my throttle down to 60% when I get to 5300rpm, I guess it thinks its overboosting. Do a log on block 003 and watch values 1/3 (rpm/throttle). Just my .02

[Seerlah]

All is good at part throttle. It is only when I go WOT there is an issue. I was thinking about doing a throttle body adapt to see if that will work (resetting the ECU). Don't know why I didn't though. I will go and do that now then go for a spin to see what happens. Update soon

Edit: Dropped a damn ratchet bit down in front of the radiator and now it is resting somwhere on the belly pan. Just great!!!!!!

Edit 2: Well, the ratchet bit ended up on the floor . And I found a thread on doing the throttle body adapt via VAG com while I currently have the ignition in the starting position readapting the throttle body to the ECU. After maybe 10 min or so, I will go and do the throttle body adapt via VAG com (for good measure), go for a spin, and post the outcome.

[flynnr]

could it be something wrong with your clutch?

[Seerlah]

I highly doubt it is the clutch. The clutch has maybe 13k miles tops on it, shifts smoothe, grabs tight, etc. I did the throttle body adapt, but did not go test it out yet. I am going to do that in a couple minutes as I have somewhere to be in a little while. So, I will test it then. If the throttle body adapt does not cure it, then I will take it to my mechanic tommorow to see what he says. He is an enthusiest so does not really charge unless he has to do real work. He should know what is going on.

[andyrew]

Can you check your a/f ratio?

Next, How about spark plugs/Coils?

Last, Compression?

Its one of those.

[Seerlah]

I will check those tommorow as it is late over here.

-I would not know how to check my A/F ratio

-I will do a compression test tommorow

-My ignition coils are good as they are basically brand new revised R versions (~1 month old). But I also decided to change my plugs to NGK BKR6E just fior kicks at the same time. I usually run Bosch F6DTC and I have a good supply of those. I will swap those back in.

But I just went to test out after the throttle body adapt, and the car just felt like it got worse. At first I felt I was in limp mode, but then in 3rd gear I was able to hit ~10 psi, so no limp mode for me. Then after a little more cruising, I realised the car is running as it is on stock mapping for the ECU. My tune is still there, as I can still go WOT and have my gauge go up to ~22psi like usual (turbo spooling just fine and all). But the car itself seems to want to float with the stock tune instead of the flashed tune. It felt wierd. As if the ECU made it's own decision upon the matter of what tune to run with.

But I will do the compression test tommorow and swap plugs back to the F6DTC. As for A/F ratio, I would not know how to go about getting those readings.

[andyrew]

You need to have someone with a reader. Or you need to be able to pull Vag-Com logs for I forget which bank.

This will also be able to tell you what the ECU deams the issue is coming from or if there are any codes being thrown.

If you were running the stock tune with 22psi, you would lean the fuck out and probably grenade your engine. Lets hope its not your tune going that crazy.



What are your mods?

[Seerlah]

Yeah, I was getting scared about that (blowing up my engine) and only did it a few times. I drive maybe 1/4 throttle not to upset the timing. I have CTapp flashed k03s, Labree HFC, and Milltek Exhaust. I am thinking to get a stock ECU and swap it out for variance. Just emailed A&P, so I should get a response tommorow. If not, I will just call them. And I saw one on ebay for $185 shipped (not too bad), so I will just go with whatever is cheapest.

But tommorow I will do a compression test and swap my plugs back out. And the thing is that the 22psi never makes it to the drivetrain. I am currently just going to drive in hg (5 psi max) till I can get this thing figured out. Oh, and there are no intermittent codes via VAG com for this issue. But I will test again tommorow.

[andyrew]

You need to pull some o2 sensor logs.

Your issue might be fuel pump/fuel filter/ or fuel injector related..

[Nebone]

Welcome to the dreaded power retard mode. Since you have vag com, check your cylinder timing retard values.

[Seerlah]

I am about to go out, get my car inspected (hopefully I pass), get my compression tested, and swap plugs. I will update in a little while. But in the meantime, does anyone know what block to log and procedure for cylinder timing retard values? I want to get this issue resolved asap. Thanks!

[kovalevandrew]

Welcome to the dreaded power retard mode. Since you have vag com, check your cylinder timing retard values.

Please tell more... Mine does a similar thing, when foot flat, after 4500rpm, the car is also flat. However, the moment i lift off even a tiny bit, it howls to life again.

[AudiRacerS4]

Please tell more... Mine does a similar thing, when foot flat, after 4500rpm, the car is also flat. However, the moment i lift off even a tiny bit, it howls to life again.

you are pulling timing because the ECU sees something that it doesnt like (ie. IAT's too high, A/F is too rich or too lean.)

[kovalevandrew]

you are pulling timing because the ECU sees something that it doesnt like (ie. IAT's too high, A/F is too rich or too lean.)

Probably running lean, need to get a diag thing so i can see what's going on.
IAT...?

[bassed]

IAT=Intake Air Temperature

[kovalevandrew]

IAT=Intake Air Temperature

Don't think it's that, doesn't like going all out when coldish either. Doesn't get worse if the car warms up, gets better if anything.

[Seerlah]

What should I do to correct this? I do not have an A/F gauge, but I have a VAG com if I need to log a certain block, do some math calculations, and get my readings. If it is the A/F ratio, then that would mean that it would be either my primary 02 sensor or my MAF (I can not log my MAF bc I can not go WOT without having issues)? No? Maybe replace my air filter to see if that helps any?

I am waiting for my engine to cool down a bit so I can do a compression test, as suggested above and change my plugs back to F6DTC. But I highly doubt that will make a difference. How would one go about checking the air intake? I will do a boost leak test also, while at it, to see if there is any rip in the turbo inlet. As for the actual airbox, how can one go about trying to clean up anything that may seem to be in the way?

[Seerlah]

Ok, if it is the A/F ratio that the ECU does not like, then I think I am diagnosing correctly. My 02 sensors are good via readiness on VAG com. Unless the primary is starting to go on me. But that sensor is maybe 6 months old (but it was spliced into existing connector and it is a Boshn non-universal unit). I sprayed the MAF with CRC MAF cleaner and am going to go for a spin after I am done scanning my car for codes (none thus far. only for my HFC and for disconnecting my battery ground). I will do another throttle body adapt before I go for a spin. I am thinking to also replace the air filter. If the problem is not in that area, then I will start looking into the fuel pump and fuel filter replacement.

I used Lucus injector cleaner on my last gas tank. Does anyone think that might have something to do with it? Or maybe because the colder denser air is moving in (NY resident)? And I went to do a compression test, and that thing was waaayyy off (rented from Autozone). My first cylinder was 60psi and the second was 70 psi while the gauge was dropping at a good momentum while I was reading it. I am thinking just to purchase my own then do a compression test then. Also swapped my plugs back to the F6DTC. I will update in a short while. But in the meantime, anyone have suggestions on this matter?

Thanks!

*please pardon for the sloppy paragraphing format

[AudiRacerS4]

i highly doubt you did the compression test the right way

[Seerlah]

No, I did it before and I had 165, 165, 170, 165 before (couple month back). That gauge was seriously fubered.

[AudiA4_20T]

WOW, this is EXACTLY what was happening in my B5, I sold the car, but have seen this issue come up over and over and no one has ever figured it out

[Seerlah]

This seriously sucks. I am going to replace my fuel filter next to see what happens. Cheap thing to do. And replace air filter while at it. Then if it comes down to it, the fuel pump.

I did not go out for a test drive yet after I checked what I could via VAG com and intake system. 02 sensors seem ok too. No code at all for them. This really sucks!

WOW, this is EXACTLY what was happening in my B5, I sold the car, but have seen this issue come up over and over and no one has ever figured it out

Hopefully, I can find out the reason behind it and save people troubles in the future. If not, I will maybe just sell my CTapp ECU and replace it with a stock mapped one. Then just go with Unitronics afterwards.

I am curious what mods did you have, if any, on your B5 before you sold it and had these complications? I really do not want to sell this car as I have already invested waaaayyyy too much money in it (maintanance and mod wise) to sell it.

Update: Just ordered a fuel filter and air filter. I will bump this thread once they are replaced to tell my progress. I did not take it to my mechanic. I will take it to him do do the fuel filter and see what he says about the issue at the same time. Till then, slow driving ................Oh, does anyone think I should also replace my air intake sensor?

[Nebone]

You don't have to go ahead and replace everything to get your car running normal. Thats why you have a vag-com to diagnose what is wrong. My car is currently sitting in the US with that virus in it and I have done much research on it. My best guess was the IAT sensor, if not that, then some intercooler issue. Leave everything as is and check/replace the IAT sensor.

Oh, and don't replace everything at once since you will never know what (if) fixed the problem.

[Seerlah]

Thanks, man. And how is Germany holding up?

The things I am replacing are things that need replacing anyways. Air filter and fuel filter. I asked about the air intake sensor, so that seem that I will replace that also. If it cures the problem, at least you know how to cure your vehicle. Anyways, I will post updates. And make sure not to get too crazy in Germany. They tend to be some heavy drinkers Be safe man!