Need some help troubleshooting

Hey guys, so last night Chad (geno) and I spent the night working on #852. Origanally planned to just wie up my SAFCII but the car was idling really low (around 500-700) and weren't sure why. Tried adjusting the BISS screw using the grounding trick to no avail. Swapped out the IAC sensor, no luck. Changed a coupler that may have been leaking at the TB elbow, nothing.. Couplse other things I forget. Well after a lot of fiddling with the throttle it now idles fine? But here's where the new problem comes in. So before it lost all power at 5k. Now it pulls all the way to redline... great! Not quite... Chad pointed it out, each gear the boost goes up. Starts at 12-14 in 1st, 15-18 in 2nd, and 20+ in 3rd. Haven't gone further as I don't want to risk detonating a healthy motor

A lot of people think it's my boost controller causing the issue, but why would it change each gear?

 

She does have bad boost creep.

Some stats of his car:
TD05 14B on what i believe to be a 7cm exhaust housing.
Modified Stock exhaust.
Two stage boost controller. TurboSx i believe.
2.5" piping around a large intercooler
2nd gen MAF
550cc injectors.
Vaccum system / Emissions deleted.

For the idle issue:
No matter what we do, the BISS doesnt adjust the idle at all. This has me screamin wtf for days.

As ninnyVR4 said, we tried grounding the system and adjusting the idle to the book.
Changed out ISC for the hell of it, Patched up any leaks we detected.
We changed out his BISS for a steel one i had laying around and we changed the o-ring.
Even tried using the SAFC2 +10% at the 1000rpm point to see if this would change anything.


Boost creep:
Mike, I have a MBC in the garage we can test on 852.
The only things I can think of is maybe its time for a wategate or porting if the MBC doesnt correct this.

Quote:

My boost is too strong! Is there a fix?
My boost won't stay where I set it - it keeps going up! Is there a fix?

This is called boost creep, and occurs when the turbo is pushing so much air that the wastegate, even when fully open, cannot dump all of the intake pressure. This results in a continual increase in intake pressure, and is common with upgraded turbos, especially with upgraded downpipes - the exhaust would rather flow through the turbo/exhaust than the more restrictive wastegate, which spins the turbo ever faster. Cars with this problem can develop mind-blowing (and engine-blowing) intake pressures in a hurry.

The general solution to this problem is to port the oxygen sensor housing, turbine housing and/or wastegate to allow them to dump more air. Otherwise minor malfunctions of the wastegate may also exhibit themselves as boost creep, such as poor travel on the wategate actuator arm. Some people use an external wastegate for better pressure control.

 

Looks like it may be time to get a external wastegate

 

[SouthCaliVR4]

Boost creep on a 14b?!? I haven't run into this before. I would think the mbc is you're more likely problem, it just has more time to build boost in the higher gears. try running your boost reference hose strait to the wastegate, you should hold at around 7lbs if not check the actuator for leaks & proper function.

low idle, check the biss port for blockage & make sure the ttl plate is proper @ idle as well as the closed ttl switch functioning as it should.

Where are you sourcing boost reference?

 

[Muskrat]

Your engine is under a higher load in higher gears. Put simply, this causes cylinder pressures and temperatures to rise, which leads to higher exhaust gas velocity as it exits the cylinder, which then drives the turbo faster. This is why you see different pressures in different gears, with poor wastegate control.

I definitely wouldn't go spending money on an external set-up. You shouldn't need it, something else is going on, but definitely associated with boost control. How did you set your boost controller? Have you done a boost leak check? Make sure the waste gate itself can actuate freely, and also make sure your waste gate actuator is working properly. I'm wondering if the gate isn't fully opening.

 

The boost controller came with the car. it's a 2-stage unit from TurboXS. Only boost leak is a hairline one coming from the BOV flange, which will be replaced tomorrow when I switch back to the stock BOV. How would I go about checking the actuator?

 

Mike,

On the the front of the turbo you have a cotter pin. On the passenger side of the turbo there are two 12mm bolts holding the WG actuator in place. Remove it and check for issue. Also make sure your flap is working properly. The flap is where the WG cotter pin slides into which is next to your O2 housing.

I have one or two spare WG actuator if you find yours in poor shape.

I was expecting your O2 dump to the atmosphere to be louder, so maybe there is a WG issue. Are you still seeing idle issues after I strung her out last night?

 

Post from another forum

"Generally, boost is set in 3rd gear due to getting as much load as you can at a safe speed. 1st and 2nd will be lower, and 4th will be slightly higher and so will 5th. Tell tale sign of creep is when it hits your sets boost, stays there for about a second and slowly starts climbing. Lets say you have a 14B and you set it at 14psi. 3000RPM you hit 14psi solid, and it stays there till about 4500RPM. Then it starts climbing slowly higher and higher as RPMS rise to 7K, by 7K you're seeing 20+ psi. That's creep. But if its just difference from gear to gear, that's just a load difference. Boost is LOAD DEPENDANT, not RPM, why you cant make 15psi of boost reving to 4K in neutral and why it spools faster climbing a hill."

Got me to thinking. After I installed my hard pipes, 2g maf etc etc.. I had to move my boost controller around just because of where it's placed. Beginning to wonder if maybe in doing so I threw off the adjustments. Only problem is I wouldn't even know how to adjust the damn thing

 

[MitsuDriver274]

14b's will boost creep with a 2.5" system, ask me how I know...

 

^^ Well! You going to tell us /ubbthreads/images/graemlins/uhh.gif

 

Nobody asked him! so... how do you know? /ubbthreads/images/graemlins/confused.gif