[omgbossis21]

Okay so I've been round and round with my car the past week or two. Some may remember I posted up about having detonation and boost problems. Well now if I have my boost controller set on (which is set to hold 10-11psi) I can hold the boost pretty well but the car hesitates/stumbles at WOT. Boosting non-wot causes the car to engine to cut pretty much completely. I spent last night soldering EVERY connection from my boost controller to the ecu and every other connection I could imagine. I had the cel scanned and had one code , p1127 fuel control (too rich). I turned my fpr back down and the boost back to 10psi (I raise fuel pressure to run 11psi which is when the code started). The cel is back on, hopefully just for the 2nd o2 sensor which is flapping in the breeze. Now, when I turn the boost controller off.... I should run set internal wastegate pressure which is 5psi. I run 5psi for a moment, the creep up to 8-10psi and it holds it????? Why? It is definitely creep as spike would hit x psi then drop back down, this holds it. Creep is usually caused by too much exhaust passing through the wastegate I believe.... I've heard of running to rich causing this. Also when the controller is off I can boost all day and not stumble/hesitate or nothing. WTF? Im am very unsure of what is going on at this point. I was thinking maybe I have a leak somewhere but I hold boost fine. Im going to pressure test the system anyway with the tester I designed. The apexi unit is accurate on every reading (rpm, speed, boost actuator voltage, TPS voltage etc). Nothing is out of spec so everything is working properly. I disconnected the solenoid that controls boost and turned off the unit. Sure enough I can blow right through the solenoid so its factory control. Turning it on makes it harder to blow through meaning the actuator is working properly. What the hell is going on here....

 

[2 UNIQ]

I had this problem about 4 years ago and no matter what you do YOU HAVE to run an EXTERNAL wastegate as this will solve your problems 100%.
No Electronic boost controller or running a larger D/P will solve your problem.Its the internal wastegate opening thats to small..
Most likely your running a pretty small Turbo that spools up fast and whats happening is the exhaust gasses are defently passing through quickly and your internal wastegate cant keep it steady..
I did alot of small fixes but nothing worked until i ran a Tial external wastegate and was so relieved.
Dont waste your money on trying to port out your existing Housing to make th eopening larger or running a bigger D/P which i originally had 2.25inch and then went to 3inch and did nothing but made it creep higher.....
I have been there an done that so to sum it up just run an external wastegate OR runa larger turbo
Hope this helps

 

[omgbossis21]

The turbo is a t-15, so its VERY small :lol: However at one time I boosting 11psi all day from 1800rpm-redline with 0 problems. Why start now?

 

[Pussykatt]

the wastegate flapper isnt opening enough. linkage may be fubared, or the wastgate is just sticking. however, you shouldent NEED an external to keep the creep down. fix the wastegate issue and you fix the creep. i suggest pulling it apart and hooking a vacume tester up to the wastegate actuator and see how much it opens at certain psi's and such.

 

[omgbossis21]

Damn, pull that thing back off :dead: I dont understand why with the boost controller on it hesistates/studders and crap when i try to run higher boost. I'll do a pressure test and get a safc. In the meantime I'll leave the boost controller off and source another turbo as I want a bigger one anyway....

 

[Pussykatt]

yeah. the solinoid has probably had it, or something is just plain sticking. its just a t15 anyways, it would probably be easier and such to find a better turbo, then use the t15 for its original intent.... a door stop.

 

[omgbossis21]

Alright I changed a few things around today and drove it tonight. It overboost with the boost controller off for sure but I enjoy it (its not as high as what I've been running). With the controller on though its all screwed up.... Im going to have to double check EVERYTHING for the controller, if its good its pissing me off and im gonna sell it.

 

[omgbossis21]

Okay I used the pressure tester I built for the intake system. Pressured it up to 10psi and found two leaks that leaked slowly (faster w/ more pressure of course). So that would of been my problem. However, you cant fix one thing without something else breaking.... Right after fixing the boost leaks I noticed a MASSIVE oil leak.... not sure exactly where im thinking the oil pan. Drained out 2 quarts of oil in 2 days Sucks !!! Guess thats what Im doing this week afterwork........

 

[Pussykatt]

maybe where you put the drain line into the pan? what did you use as a gasket to seal the pan onto the block? maybe rear main is going bad?

 

[omgbossis21]

I am using a scoupe turbo oil pan. I used rtv gasket sealer like the dealer calls for to seal it. I found the leak today, it was where I tapped into the oil pressure sending unit to feed the turbo. All taken care of now =-) Boost is back to normal , car is running great with nothing more than a hesitation in the lower rpms (prolly rich as hell). I turned the boost back down to 8 from 10psi b/c the car just runs better. Its on hold to I get my apexi safc (hopefully for x-mas) :evil: