Single turbo tuning help...

[Terry@BMS]

Ultimately its your call. With a 17psi spring and map 4 programmed to allow only up to 15psi, it's just going to close the throttle to try to compensate. The PID algorithms are setup for 13psi springs as well. You can make a 17psi spring work but its the wrong way to do things.

Anyway, map 2 has a 17psi target. Once fueling is working So you'll want to set FF to 0 and try logging map 2 to evaluate boost control. With FF at 0 PWM should stay around 0.

[Linracing]

SMH

[mjmarovi]

Ultimately its your call. With a 17psi spring and map 4 programmed to allow only up to 15psi, it's just going to close the throttle to try to compensate. The PID algorithms are setup for 13psi springs as well. You can make a 17psi spring work but its the wrong way to do things.

Anyway, map 2 has a 17psi target. Once fueling is working So you'll want to set FF to 0 and try logging map 2 to evaluate boost control. With FF at 0 PWM should stay around 0.

Gotcha. Well it's a 1 bar spring, so I guess it's actually like 14.5psi right? I told the shop to begin with I wanted a 12 psi spring, they asked, then they told me that was too low, then I had to drive back up yesterday to have them swap it and now I see it's still a bit too stiff...this is $#@!ing annoying...

Anyway, I disconnected the small black subconnector and the codes still came back. My O2's are in same exact locations as @Ak335i, so I guess if it's not placement, and not tune related...just coincidence one or both went bad? This is downpipe we're talking about right?

[Terry@BMS]

If it was a 15psi spring, why was boost 17-20psi in your earlier log?

Not likely both sensors are bad... Codes would be from primary sensors.

[Tony@VargasTurboTech]

Gotcha. Well it's a 1 bar spring, so I guess it's actually like 14.5psi right? I told the shop to begin with I wanted a 12 psi spring, they asked, then they told me that was too low, then I had to drive back up yesterday to have them swap it and now I see it's still a bit too stiff...this is $#@!ing annoying...

Anyway, I disconnected the small black subconnector and the codes still came back. My O2's are in same exact locations as @Ak335i, so I guess if it's not placement, and not tune related...just coincidence one or both went bad? This is downpipe we're talking about right?

The odds both O2's went bad are slim to none unless of course they got burnt up. Pull your plugs, are they rich, are they lean, are they wet with fuel, etc. We had the car apart for like 2 months for a bunch of stuff, put it back together it missed and ran crappy and threw those exact lambda codes, turns out 2 injectors were bad, one in each bank, they just went bad sitting there, car ran fine when we parked it, I swapped all 6 and its never ran better. My suggestion is, MAKE SURE all boost / vacuum lines are in their right place, then pull plugs and start seeing what its doing, run it and pull plugs right after you shut if off, if you have injectors going bad, the plugs will be wet on the ones that are, but it wont last long with a hot engine.

[Ak335i]

prob bcuz lines to mac solenoid and wastegate/compressor mixed up..

thats why i would keep it simple and bypass that to see what the wastegate runs at.. but hey i only did that from the start and have never had boost issues lol

[Tony@VargasTurboTech]

prob bcuz lines to mac solenoid and wastegate/compressor mixed up..

thats why i would keep it simple and bypass that to see what the wastegate runs at.. but hey i only did that from the start and have never had boost issues lol

Still find it literally unbelievable a custom build and install of that magnitude would be allowed to leave the shop without at least 100 miles on it, and a starter tune to make sure its not over boosting, etc. To just throw the car back at the op with all these issues? Don't get it.

[Ak335i]

Still find it literally unbelievable a custom build and install of that magnitude would be allowed to leave the shop without at least 100 miles on it, and a starter tune to make sure its not over boosting, etc. To just throw the car back at the op with all these issues? Don't get it.

i picked my car back up from proven power and within a day drove it to long island new york and back to south florida over a long weekend 3k miles with zero issues.

the shop knows what they are doing this is clearly a tuning/boost control issue on the OPs car. They dont tune the n54s and i knew that/know that and so does the OP.

[Tony@VargasTurboTech]

i picked my car back up from proven power and within a day drove it to long island new york and back to south florida over a long weekend 3k miles with zero issues.

the shop knows what they are doing this is clearly a tuning/boost control issue on the OPs car. They dont tune the n54s and i knew that/know that and so does the OP.

I am not trying to knock them I know they build good stuff, just trying to wrap my head around how a guy just picked up his car and is posting on here to solve his issues. We are not tuners, do not know the first thing about tuning, but if someone does a 10K+ turbo kit and install with us, I will make damn sure I am on the phone with the person who does tune these cars, aka terry in this case, he is an email away. I am sure Terry could have provided them with a starting point, in order to check wastegate operation, etc, but to give a car back with possible vacuum / boost lines routed improperly, reoccuring lambda codes, etc. In my opinion it ust shouldn't leave a shop like that.

[Ak335i]

I am not trying to knock them I know they build good stuff, just trying to wrap my head around how a guy just picked up his car and is posting on here to solve his issues. We are not tuners, do not know the first thing about tuning, but if someone does a 10K+ turbo kit and install with us, I will make damn sure I am on the phone with the person who does tune these cars, aka terry in this case, he is an email away. I am sure Terry could have provided them with a starting point, in order to check wastegate operation, etc, but to give a car back with possible vacuum / boost lines routed improperly, reoccuring lambda codes, etc. In my opinion it ust shouldn't leave a shop like that.

idk. worst case ill be home in two weeks and meet up with him and get him sorted out. its honestly a easy process of elimination

[mjmarovi]

I have checked vacuum lines myself, triple checked earlier and I am 100% positive they are correct. I think my boost control is actually not too far off now, but I want to rid this lamda code issue first before getting back out amg doing more pulls.

Tony, thanks for the advice checking the plugs, I am out of town till Sunday but will do it then. The thing is...those codes don't seem to affect the car whatsoever. It idles and drives perfect. Only thing is when the code is thrown afr just reads 20:1....I can clear then afr reads fine. It's weird.

I also get that faulty low fuel pressure sensor code. Could that cause the lamda codes too? Not familiar with that code either.

[Terry@BMS]

29F3 means your low fuel pressure sensor is bad or has an implausible reading. It's easy enough to swap the sensor.

[Tony@VargasTurboTech]

I have checked vacuum lines myself, triple checked earlier and I am 100% positive they are correct. I think my boost control is actually not too far off now, but I want to rid this lamda code issue first before getting back out amg doing more pulls.

Tony, thanks for the advice checking the plugs, I am out of town till Sunday but will do it then. The thing is...those codes don't seem to affect the car whatsoever. It idles and drives perfect. Only thing is when the code is thrown afr just reads 20:1....I can clear then afr reads fine. It's weird.

I also get that faulty low fuel pressure sensor code. Could that cause the lamda codes too? Not familiar with that code either.

If the car is idling smooth, its prob not the injectors, they are almost always shown with a slightly shaky idle. Let us know how it works out.

[mjmarovi]

29F3 means your low fuel pressure sensor is bad or has an implausible reading. It's easy enough to swap the sensor.

Seems odd, I wouldn't think it would go bad after sitting. Could the 255 inline the shop installed have anything to do with it?

[135pats]

Seems odd, I wouldn't think it would go bad after sitting. Could the 255 inline the shop installed have anything to do with it?

They crap out all the time. Went bad on both of my N54s for unrelated reasons.

[mjmarovi]

29F3 means your low fuel pressure sensor is bad or has an implausible reading. It's easy enough to swap the sensor.

They crap out all the time. Went bad on both of my N54s for unrelated reasons.

Would a dealership have this in stock? Any diy to replace or where is it located?

[Tony@VargasTurboTech]

Would a dealership have this in stock? Any diy to replace or where is it located?

Most dealers will have it in stock, Drop your charge pipe, then pull your throttle body, it will be right there, be careful when removing the plug that you don't break the clip, they are fragile. You will need a big wrench the older ones are 1" 1/8 if I remember right, the newer ones are smaller, also the old ones use an o-ring, the new ones use a copper crush washer, Do not over tighten them, they can break, just unscrew it and, screw the new one in, and snug it down.

[mjmarovi]

Most dealers will have it in stock, Drop your charge pipe, then pull your throttle body, it will be right there, be careful when removing the plug that you don't break the clip, they are fragile. You will need a big wrench the older ones are 1" 1/8 if I remember right, the newer ones are smaller, also the old ones use an o-ring, the new ones use a copper crush washer, Do not over tighten them, they can break, just unscrew it and, screw the new one in, and snug it down.

Must spread gayutation, but thanks T! Roflshdmt!

[mjmarovi]

^^ not bad, but still over boosting though. Throttle wants to close.

I don't know if that's throttle wanting to close from JB4 or if just cause I was only partial pedal

[mjmarovi]

@Terry@BMS I just thought of this...is it possible I'm getting these lambda codes and sensor codes cause I don't have the JB4 downpipe fix and no longer have a COBB as a backend to take care of those codes?

I've read somewhere else where someone replaced O2 sensors and it also took care of the low pressure fuel sensor code as well. I'd hate to spend $400 on O2 sensors and then realize the problem is still there....I wold think if O2 sensors were really bad then car wouldn't idle right, or drive smoothly, and AFR wouldn't come back to reading normal after deleting codes either. Thoughts?

[Terry@BMS]

Nope, none of those codes are normal. Only 29F4/29F5 are normal codes for a competition race only exhaust application like you run. I don't know if your sensors or bad or if there is some other issue at work. But the codes are abnormal.

Primary o2 sensors are around $110 shipped each on Amazon btw.

[Payam@BMS]

I don't know if that's throttle wanting to close from JB4 or if just cause I was only partial pedal

Even if you're partial pedal, I believe it goes by load. If you pass a certain point of load % it will still act like 100%. I may be wrong here.

[mjmarovi]

Even if you're partial pedal, I believe it goes by load. If you pass a certain point of load % it will still act like 100%. I may be wrong here.

Gotcha, pretty much going to have to wait till Tuesday or Wednesday and try replacing O2 sensors if I have time before vaca

[The Ghost]

edited by request

[mjmarovi]

Primary o2 sensors are around $110 shipped each on Amazon btw.

Couldn't find it, was that the BOSCH non BMW marked one? Turner has them fro $110 as well. I take it that needs to be hardwired in though? No harness? Or does this harness pictured work? Here's the link. I'm also guessing I can just order two of these and replace both.

http://www.turnermotorsport.com/p-18...da-sensor.aspx