Ok, this is getting annoying (lack of boost)

Well, same behavior. I drove about 20 miles on DAB0, and it would hit 16psi (not 15 strangely) when I would punch it at 3000rpm, I'd give it about half a second there and back out. The odd thing is, I think the car used to do 13psi in DAB0, 18psi in DAB1, etc., but now it's doing 16psi in DAB0/1/2/3, in all settings.

Here's another fun behavior that I got too. In DAB2, I punched it in 3rd at about 60mph, and it went right up to 15/16 like it should, then at about 4500rpm all of a sudden I felt the torque and it jumped to 18psi, then fell back down to about 15psi by 6000rpm.

I'm stumped, about to give up and part the sucker out, but I must do another boost leak test ASAP, it's just this is not a behavior that is at all like it was when I was leaking before.

One last question before I dynamite this thing, if I had a bad WGA, could it cause this behavior? Boost going up/down etc.? What kind of damage to the WGA would cause that? I know I was having issues holding boost before, spiking 25psi and holding that until about 4800rpm, then it would fall steadily to 17psi by 6400rpm, but I can't be certain if that was the WGA or the boost leak.

 

there's no way that you're going to run 25psi on ecu controlled boost. it's just not designed to do so. the ecu will pull timing and all sorts of fun stuff if you try. you had a boost leak so the ecu wasn't fully aware of what was going on. now that things are fixed, the ecu is back to having full control over things. the stage ecu's are designed to run at a certain POWER output, not psi output. the ecu will pull timing, fuel and boost to achieve those outputs. that's what's going on. if you want to run 25psi you have to take control away from the ecu.

 

Right now you just have people making huge assumptions and throwing out solutions.

My advice would be stop looking for the zebra. Alot of times if you hear the clip clop of hooves you should think horsey not zebra.

Point is start with the simple and work your way up.
I would first check all the vacuum and boost lines making sure they are connected and secure.
Then I would check the connections to all of the relevant sensors map,tip,intake temp etc.
Check the plugs, plug wires, pcv and connecting lines etc.
Just make sure that all the basic stuff is connected and working properly.

Reset the ECU and then drive it easy for 50 miles or so to make sure the ECU has the time to adapt to everything. Then do a couple pulls and see what happens pay attention to what the outside temp is as well. If you still feel that something is wrong then the next step would be to data log paying specific attention to injector DC, pulse widths, wg DC, knock retard, timing advance, EGT's. At this point you should be able to comfortably say if something is wrong or the ECU is behaving as designed.

 

data loging and resetting the ecu isn't going to do it in this situation. if this was a stock s3 then i would agree with you. when you have someone running aftermarket parts trying to change the perameters of how the ecu is meant to work then everything gets thrown out the window. there's no way to tell if something is "wrong" because there's no way to tell if it's right in this case.

the best thing to do honestly would be to put the s3 wga back on and see what the car does. if it's holding what's considered normal boost then there's nothing wrong. when you fight the ecu you will lose.

 

Considering you don't know what the IAT's are or any of the other parameters that go into the ECU's calculations how can you claim to know what normal boost is? I mean without knowing IAT's, what altitude he is at etc. etc. etc. you can't claim to know what a normal boost level is. I am at 5600ft and my normal boost level is much different than someone at sea level. I agree with putting the s3 wga back on but the rest of your advice seems to be that of someone waxing intellectual, no offense.

I didn't say datalogging was gonna fix it but at least he would have an idea as to what the hell is going on. I mean regardless of the setup if the ecu is trying to pull timing or fuel etc. that would be useful information would it not?

 

you're getting into semantics that honestly don't matter and are making things more complicated then they need to be. "normal" boost for a s3 car is usually somewhere around 20psi. most people will agree on that. if it's significantly different then there's a problem. if it's a little on the cold side and he's seeing 18psi then it can be considered normal. if it's a little warmer and it's 22psi, it can be considered normal. if he's seeing 11psi, something is wrong. it gives you an idea. your normal boost isn't going to be THAT different due to altitue, it's going to be different due to temperature and humidity. don't tell me you're one of those "well i ran a 13.5 but if i was at sea level it would have been a 13.0!" people? haha

but again, in this case it doesn't matter when you're fighting the ecu. everything gets thrown out the window. how can someone sit here and say that their car isn't running right when there's no way in hell to know that considering that there are aftermarket parts on the car? put things back to what they should be and go from there. start simple then get more complex, it generally works better that way.

 

Thats exactly what I said(kind of) on the first page, but no one listened to me either.

 

huh what did you say something? :what:

 

The point I was trying to make was you never asked for the basics, like temp. I'm pretty sure you are not house so you need at least a little more info on the situation to diagnose it.

Haha If you read your last sentence you and I are repeating each other. Good at least we agree on where he should start. :muscle:

 

Muahahahahahaha....wait.....what???:whistle:

 

Uhm, ok so the ECU isn't supposed to push a steady 25psi... but it used to do that. I mean I DID trap 117, and the previous owner DID trap over 120 many times, with the same setup. There's no way it would be making the power to trap 117 on 15psi like it is now, so if the ECU is trying to make a certain power level, it must be trying to make a lot less now than it was trying to make a month ago.

Maybe it is the ECU, but it used to behave a LOT better, it used to hold 25psi up to about 5200rpm, and fall off to 19 by 6200rpm.

Either way, I guess I'll throw an MBC on it now and see what happens.

 

If you guys think him fixing a boost leak will cause the PCM to keep the boost at 15psi spike on DAB 0, DAB 1, DAB 2, DAB 3 then your highly wrong. What's the Dial-A-Boost feature for then if no matter what setting he uses he is still spiking the same.

The Stage 3 w/toys car I drove will full bolt-ons including the AGP wga on PCM controlled boost spiked 21psi and held it for the most part till redline. This was on DAB 1/2. I don't recall but DAB 3 on this same car is at 26-28 spike.

Weather will play a part on what the PCM inputs and puts out. So parameters such as IAT readings plays an important role as to what the PCM will correct itself to. Colder weather outside the pcm will take boost away.

 

Weather will play a part, and it IS colder right now, at least in the 50's, but there's no way Stage 3 is supposed to put out 15psi on all settings, that's for sure.

I am confused, I have to believe I have a messed up wastegate, bad boost solenoid, or some boost or vac leak. I'm going to try to test for the leaks again ASAP, and maybe borrow either a MBC or someone's WGA to swap in.

 

I seriously doubt 50 degrees will effect it that much.

There was a time on mighty's quat where we ended up bending the wastegate by setting too much of a preload.

If you can get ahold of a scan gauge that should help you figure out what is going on quicker.

 

I've got a scan gauge hooked up, but what parameters should I be looking at? The scan gauge does not read the DTCs off of a Stage 3 PCM though...

 

are you sure that you have your vacuum lines correct? and your wiring for the toys harness? sounds like your dab isn't working at all.

 

Well have you checked the basics like IAT's, map reading, WG DC, maybe even KR, and timing advance to see if the ECU is holding back for some reason.

 

Yep, none of that wiring changed at any point, and I just rechecked the vac lines. The difference between 25psi and 15psi was it sat for a week during Xmas vacation. The day the boost leak got fixed, the car ran fine and gave me 25psi as it always did, then I parked it for a week, and since I got back it's been at 15psi.

DAB is working in some sense, maybe not properly, but it is doing something. If I go to DAB0 I get 15/16psi, but if I raise it to DAB1/2/3 it will sometimes sputter and go for 20-22psi briefly, then back down to 15psi, or other times it will just stay at 15psi and never try to go above that. It sure seems like a boost leak again, but I swear I tested it after I fixed the leak and the way the car "drives" and feels, it's nothing like when I had the boost leak before.

I've watched the WG DC and KR and timing advance, but I never logged them before so I'm not sure what is out of the norm.

I get zero KR, sometimes 1-2 when I let off the throttle but that's normal, timing advance at 15psi rises to about 28 degrees over 5000rpms, and the WG DC, well that changes a lot, what exactly should I be watching for there?

 

Is it really high or really low. IIRC most run about 50 to 60% DC.

 

Well, it's going to vary based on RPMs and boost level, right? I think if anything it should show that it's really high, i.e. letting out too much of the boost, if it's malfunctioning, but as far as I can tell it's not doing that. I see 40-50% at various times under boost.

I've decided to try a new WGA and MBC as soon as I can, and still trying to find someone with a regulated air compressor to do a boost leak test.