APR Stage 3+ Boost Issues NEED HELP.. Sorry ahead a time for the long message.. but..

[Chr1sJohnson]

Hi,

I'll go ahead an apologize for the long message, but for the love of God please someone help, I am completely lost as to where to go next... Here it goes......

In short, I am having some very strange issues with boost under heavy load, and also normal driving conditions. For example, if I am at a red light and I give my car all it has in terms of pressing the accelerator down, I will not go past 15 PSI boost. Another scenario would be if I am on the interstate going about 60 MPH and if I gear down to 3rd or 4th gear and give my car full load, the boost will increase past 15 and intermediately go up to 17-19 MAX, but it kicks back to 15 and holds.

I went to my local shop that installed it and I asked them what there experience was with their 2007 Audi A4 that they had in which they installed the same kit on the car and they are able to achieve 25-27 PSI under heavy load upon acceleration, and the boost holds. They also said that when they are cruising on the interstate going 60+ they are able to achieve 20-25 PSI while not going below 20 PSI.

I decided to have my car smoke tested and noticed a leak coming around the compressor cover on the intake side of the turbo. It was leaking 10 inches of air pressure. The smoke machine was set at 10 inches of pressure and it was bleeding smoke out of the compressor cover. We applied RTV to it and resealed it.. The leak was now gone, and we decided to test drive the car and I noticed immediate increase of torque and the boost PSI quickly reached 25-27 PSI under heavy load on acceleration and would hold. After we continued to drive the car for about 3 or so minutes coming to a complete stop and then accelerating again under same conditions, the boost pressure then would only achieve a MAX of 15 PSI under heavy load. We tried the interstate and giving it heavy load at 60+ MPH and it would get up to max 17 PSI, but would decrease like it was previously.

I checked for leaks AGAIN, and it’s not leaking anywhere, we’ve tried many times to locate something out of order, but not able to find anything.

I find this to be very strange considering that A) My car was able to achieve the boost that my friends car is able to produce for a VERY short amount of time before then going back into the same conditions as it was before.

I own an official VAGCOM cable and would be willing to do some tests if you think that is my next way to try and troubleshoot.

Please provide some incite as what to do next, I am under the impression that my car should be boosting much higher than it is currently, and obviously my car was able to achieve this for a short period of time, but now is back to the old conditions. It sounds like there is a software issue, or something is just off. I double checked the Diverter valve, and it has been upgraded twice to two different styles, no change, and no oil located in the diverter valve, or in the turbo itself.

Would love to find out whats going out, sorry for the long email, but just wanted to be as thorough as possible.

Thanks in advance

[907DAVE]

I had this exact issue. May not be yours, but be sure to check fuel trims. In my case they were pretty high and the pcm was limiting boost to keep everything in check.

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[Chr1sJohnson]

I had this exact issue. May not be yours, but be sure to check fuel trims. In my case they were pretty high and the pcm was limiting boost to keep everything in check.

Sent from my SM-G925I using Tapatalk

Thanks for the response! I will definitely look into this. It's certainly a weird situation, especially considering so much of what others have tried in other messages on this forum I have ruled out (upgraded diverter valve, triple checked for leaks, inspected turbo, wastegate adjustment to see if it would make an difference which it didn't, checked for any faulty lines such as the intake hoses, any electrical wires out of whack. I've even had my car reflashed at the local shop just incase it was a software thing.

Just to recap from earlier... Knowing that I did find a boost leak around the seal of the turbo and after applying RTV, sealing it back up and noticing gains of over 10-12 PSI from the normal 14 PSI under heavy loads is CRAZY... I was pushing over 25PSI and increasing, which is what i've heard some guys get with this exact same APR Stage 3 setup. What is even crazier is just moments later I fall back to maintaining no more than 15-16 under heavy loads. You would think it would be the RTV not doing its job, or another leak popping up somewhere else, but thats not the case. This is driving me nuts!!

I will add also that I only run my car in the APR 100 Octane mode (I use 100 Octane non-ethanol racing fuel from sunoco). I have been doing so for a couple of years. The ONLY time I have ever managed to get a check engine light is when I switch back to the 93 Octane mode and under heavy loads i'll get one code reading "P0299 - Boost Pressure Regulation: Control Range not reached". I would assume this has something to do with the fact I am using race fuel and using the 93 mode, because I never get that check engine light when using the 100 octane mode.

[Chr1sJohnson]

Just a couple of pictures I snapped while I was resealing the turbo and checking for leaks.

[IMG][/IMG][IMG][/IMG]
[IMG][/IMG]

[907DAVE]

Is there a chance after that compressor reseal the the pcm memory was cleared? Mine would boost hard right after a memory dump then shortly after revert to a low boost level. I fought mine for quite some time, doing all the things you described including the compressor reseal without any real progress. My car ended up having the wrong injectors in it (previous owner/ shop), after the correct ones were in there all my issues went away. The fuel trims were still a bit on the high side but I just lived with it as the performance was not suffering. Early this summer I had ditched the foam filter / air horn setup apr used on the early versions for a cone filter and my fuel trims returned to a completely normal level. May not be your issues just my experience. I suggest you focus on the fuel side of things and see where they take you.

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[Chr1sJohnson]

Could be. I will take a look. As far as the injectors I am still using the same ones supplied by APR that was included with the stage 3 kit. If it is a memory dump, what would you suggest I do to resolve that? I literally was boosting over 25psi holding and then one of the couplings on the front of my intercooler popped off and I went back to my shop and reattached it with new clamps and it hasn't been going over psi since. Very odd.

- - - Updated - - -

Going over 15 psi since I mean

[Okedokey]

Sweet colour.. Wrap?

[rongeur]

A quick log of boost specified v boost actual can help determine leak vs ecu adjustment.
If ecu is only calling for lower than expected boost, start logging fuel pressures and trims to make sure adaptations are normal range.
Maybe try unplugging your maf and see how the system responds, give the maf a good cleaning.

I tend to agree that a system trim reset was responsible for the return of power and the ecu is seeing something that is telling it to taper back to keep safe.

Any codes?

[Chr1sJohnson]

I'll look at doing some logs. How would I adjust the ECU so that it doesn't taper back?

The only engine light I seem to get is if i am using 93 Octane mode and under heavy loads this pops up: P0299 - Boost Pressure Regulation: Control Range not reached". I don't seem to have that code pop up if I am running 100 octane on the 100 octane mode which I normally do.

I will also add that I have installed a Air/Fuel gauge (Podi) and under heavy loads I am reading 7.5 and holding, which seems way off.. thoughts there?

[rongeur]

I'll look at doing some logs. How would I adjust the ECU so that it doesn't taper back?

You can't really, the ECU is very self protective, you have to find the source of what is wrong and the ECU will bump up the mapping

The only engine light I seem to get is if i am using 93 Octane mode and under heavy loads this pops up: P0299 - Boost Pressure Regulation: Control Range not reached". I don't seem to have that code pop up if I am running 100 octane on the 100 octane mode which I normally do.

Maybe consider reverting back to 93 oct fuel and programming, not sure if race mode supresses certain things?

I will also add that I have installed a Air/Fuel gauge (Podi) and under heavy loads I am reading 7.5 and holding, which seems way off.. thoughts there?

That is way off indeed if reading correctly, check against the ECU logging of AFR to see if real. Clean maf with some maf cleaner.

[canadianA4B7]

Map sensor. 3 bar or oem 2.5 bar or whatever it is. I know I had peak boost issues on the GTX 2863, car was fine for a few weeks of learning I guess, then one day just decided 20/22 psi was max reachable boost. I logged and traced and logged and looked and nothing was out of Wack. Someone noticed in my tune boost requested was obviously not meeting requested at all. Whom ever it was that looked suggested the 3 bar map sensor. After that install hitting 26/28 psi was an every push of the peddle event.

Might wanna look there.

[rongeur]

Your Wideband sensor is probably dead.

[canadianA4B7]

Your Wideband sensor is probably dead.

Mine?? I've not ever had issue w that. But I guess something I shud replace since it's never been replaced. Everything else is new in mine.

[rongeur]

Mine?? I've not ever had issue w that. But I guess something I shud replace since it's never been replaced. Everything else is new in mine.

Not yours, sorry, OP. 7.5 is not really a plausible reading and a quick google search brought up locked 7.4/7.5 likely means dead sensor or malfunctioning at the least.

[Chr1sJohnson]

Not yours, sorry, OP. 7.5 is not really a plausible reading and a quick google search brought up locked 7.4/7.5 likely means dead sensor or malfunctioning at the least.

Could be dead, or not programmed correctly? IT reads around 22-24 idle, but when full throttle jumps down to 7.5. I have the VEI Systems V1 Series / Innovate LC-2 Air Fuel Radio Controller. I bought it new and had a local shop install it not long ago, perhaps it was hooked up incorrectly, or needs to be programmed?

[Chr1sJohnson]

That is way off indeed if reading correctly, check against the ECU logging of AFR to see if real. Clean maf with some maf cleaner.

I'll clean the MAF and try this first. I am pretty new to using the Vagcom and haven't done any logging previously, so I am going to need to do some research on the forums on how to do this, and also need to understand what I am going to be looking for.

[Chr1sJohnson]

Map sensor. 3 bar or oem 2.5 bar or whatever it is. I know I had peak boost issues on the GTX 2863, car was fine for a few weeks of learning I guess, then one day just decided 20/22 psi was max reachable boost. I logged and traced and logged and looked and nothing was out of Wack. Someone noticed in my tune boost requested was obviously not meeting requested at all. Whom ever it was that looked suggested the 3 bar map sensor. After that install hitting 26/28 psi was an every push of the peddle event.

Might wanna look there.

Yeah it's very odd that I was reaching over 25 PSI and climbing for moments, I honestly have never gotten boost like that (the only time is after I resealed the turbo with RTV, and then... mystically it's gone. There has got to be something going on with a sensor, or the ECU not reading correctly. So you are thinking I have a bad MAF sensor, and I should install a 3 bar map sensor?

[Chr1sJohnson]

Map sensor. 3 bar or oem 2.5 bar or whatever it is. I know I had peak boost issues on the GTX 2863, car was fine for a few weeks of learning I guess, then one day just decided 20/22 psi was max reachable boost. I logged and traced and logged and looked and nothing was out of Wack. Someone noticed in my tune boost requested was obviously not meeting requested at all. Whom ever it was that looked suggested the 3 bar map sensor. After that install hitting 26/28 psi was an every push of the peddle event.

Might wanna look there.

So I am running th 038 906 051 D Map Sensor, is this 2.5 or 3 BAR? I found a Bosch Map Sensor 0 281 002 401 online that is 3 Bar and looks to be plug and play, but I would think that when I purchased the APR Stage 3 kit it would have come with a new Map sensor?

[907DAVE]

Curious to see what you find. You don't really need to do any loging, just bring up the fuel trim group and see where you're sitting.

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[Chr1sJohnson]

I'll clean the MAF and try this first. I am pretty new to using the Vagcom and haven't done any logging previously, so I am going to need to do some research on the forums on how to do this, and also need to understand what I am going to be looking for.

I checked the MAF sensor and cleaned it, and so I have ruled that out to be bad.

[rongeur]

I checked the MAF sensor and cleaned it, and so I have ruled that out to be bad.

As in MAF is good or bad? Try just unplugging it and driving. That should switch the ECU from MAF based to MAP based.

Logging is fairly easy, deciphering the data is the tricky part.

Once on the VCDS home screen, click the Select (Select control module), then click Engine, then go into the Adv Meas values. This will allow you to log up to 12 variables while driving. Be sure to activate turbo logging to get more data points. If you have a friend, have them click start and stop. If by self, you may have to click then get up to what you wnat to log, then stop and click stop. The data will be continuous so you may have to trim some of the data. Manually copying and pasting into Excel is the easiest way to create trend graphs and convert absolute values to more recognizable units (bar to PSI etc). The pressure readings are from atmospheric so you will have to see what the MAP reads at idle to get your atmospheric reading and then subtract that value from the boost values to get relative boost values which is what most people discuss from. For example, the ECU will read peak boost at 34.7 PSI (14.7+20) when the relative boost is 20 PSI (boost gauge reading).

To find your values, you just need to scan through, I have yet to find a great expanded table of all sensors etc. APR put this together which gives you a starting point
https://www.goapr.com/support/datalogging.php

If you grab those logs, 3rd gear pull from 1000-redline for each data set, I can help put in into Excel. The file is a txt file from the log, just post it to a dropbox location to share.

[Chr1sJohnson]

As in MAF is good or bad? Try just unplugging it and driving. That should switch the ECU from MAF based to MAP based.

Logging is fairly easy, deciphering the data is the tricky part.

Once on the VCDS home screen, click the Select (Select control module), then click Engine, then go into the Adv Meas values. This will allow you to log up to 12 variables while driving. Be sure to activate turbo logging to get more data points. If you have a friend, have them click start and stop. If by self, you may have to click then get up to what you wnat to log, then stop and click stop. The data will be continuous so you may have to trim some of the data. Manually copying and pasting into Excel is the easiest way to create trend graphs and convert absolute values to more recognizable units (bar to PSI etc). The pressure readings are from atmospheric so you will have to see what the MAP reads at idle to get your atmospheric reading and then subtract that value from the boost values to get relative boost values which is what most people discuss from. For example, the ECU will read peak boost at 34.7 PSI (14.7+20) when the relative boost is 20 PSI (boost gauge reading).

To find your values, you just need to scan through, I have yet to find a great expanded table of all sensors etc. APR put this together which gives you a starting point
https://www.goapr.com/support/datalogging.php

If you grab those logs, 3rd gear pull from 1000-redline for each data set, I can help put in into Excel. The file is a txt file from the log, just post it to a dropbox location to share.

I will do these things you suggested! Also wanted to include this as well:
Mass Air Flow Idle range from: 4.33 to 5.03 g/s
2500 RPM:8.22 to 8.47
4000 RPM 14.88-15.02

Fuel Rail Press - 4800 Kpa REL IDLE
Calculated Load Value 29% IDLE

2 Faults:
Mass Air Flow Sensor (G70) P0100 - 004 - Supply Voltage - Intermittent

Boost Pressure Regulation P0299 - 002 Control Range Not Reached at Load 84% at 5758/RPM

[rongeur]

Those maf readings are way low for 2500 and 4000 rpm. I would expect you to be fully spooled by 4000 and should be pushing way more air than that.

This was an older thread about max maf values.
http://www.audizine.com/forum/showth...MAF-max-values

The underboost code still implies a leak somewhere, double check PCV. Unhook the flex tube from PCV to manifold and blow into it, if you can blow through it, the check valve is shot. Forget about smoke, charge the intake system after the turbo blocking off the rear pcv and see of it holds pressure. Air will leak through the turbo journals and rear pcv when performed on turbo inlet. The PCV will be an internal leak to tue valve train and smoke will not be observed (i am pretty sure)