I been having this issue where my boost will go to around 15psi, hesitates and stays there for about 1/2 second then finally go to 27psi. I got a meth kit and I tried adjust my start on anywhere from 2psi to 10psi but same thing happens.
anyone have any idea whats going on. I am using a MBC and labonte meth/failsafe. stock turbo

 

bump

 

I am no pro but 3 things are coming to mind right away. First check your plugs! Also do you have an upgraded WG actuator? Seems like maybe your stocker is hating you right now. Also, please log it and post the results. I am sure it will tell you something

 

Sounds like you may have a boost leak thru the nozzle for the meth kit which is enough to limit you 15psi, once the system is active giving enough pressure to the nozzle which negates the boost leak.

Did you have this hesitation before you installed the meth kit? I believe you were running somewhere around 22 to 23 psi before and I don't remember you having this issue, correct me if I'm wrong?

Maybe take the nozzle out or plug it and turn the meth kit off so it doesn't spray, convert back to the straight pump gas map and see how the boost responds.

I could see your issue if you were running an EBC but not with a MBC.

Hope this helps

 

I agree but I am not informed on meth kits. I think its the devil actually. Sorry to be of no help on it.

 

I have an identical hesitation at about 13psi....spools, pauses at 13psi (0.9bar) for a split second, then boosts up to whatever (27psi). And I run an EBC.

Ideas?

 

Could you explain to me what you mean by that? The reason I ask is because in certain situations my car will hesitate almost bog down then jump right back into it. My car never used to do this however right after I got tuned I noticed this. The only other thing changed besides the tune was that my Apexi AVC-R was finally connected to the vacuum lines.

Therefore my issue must be from one of the two things. I am working with my tuner but have been at school and not able to deal with it since my cars is bac at home. Anyway this just caught my eye and I am hoping you could expand on that. Thanks for the help!

 

my ebc seems to cause my car to hesitate when it takes over from wastegate. My meth kit has the same hesitation. I have them both kick about the same spot now so I dont notice it. When I had my vaccum lines switched it would cause me to go from 15 to 25 to 15 over and over.

 

mine did this when i have the failsafe plugged in, it wasnt acting right so i have the failsafe under its own power source so the fail safe is always on... and when i go to give it gas it will hit up to wastegate pressure then once it senses the flow then it will jump up to where the boost should be... i just got tired of it so i just unplugged the failsafe and said screw it havent had the problem since

 

How'd you unplug the failsafe?

 

The EBC's monitor Boost Pressure with a vac line to the controller or map sensor that it uses. Also has a solenoid that is open/closing with duty cycle based on the EBC controller.

With a MBC there isn't anything that is monitoring boost for it to react too. It will be a bleeder style more than likely and these act like a boost leak before the w/g. There should be zero hesitation with these unless something like a boost leak or a turbo that is on it's way out.

 

welcome to my life. Been dealing with this problem since it got cold. Your using a EBC and its doing it? My MBC will do it when its turned to far down to prevent boost creep in the winter.

Let me know if you resolve the problem. I did everything i could. Rerouted hoses, swaped out springs in MBC, checked for leaks...blah blah blah I might change the plugs soon to see if that helps (doubt it)

here is a video for anyone that wants to see what he means.



notice in 3rd gear WOT it will hit around 14psi, stop, then peak around 6k! Very laggy.
hope it helps. not trying to hijack

 

Yeah my EBC does similar stuff to the above.

Running a Greddy Profec B spec 2 with two settings, high and low.

Low boost I get 1.5 bar with the following settings (all in bar here):
set at 70
gain at 5
set gain 0.14 (not a typo - more on this later)
peak boost 1.60
limiter at 4

What happens is that accelerating from low rpms at WOT it's fine but from part throttle it spools to 0.9 bar, holds for a sec and then FLIES to 1.5 bar. Very annoying hesitastion. However, if I set my set gain to something reasonable, such as 1.2, 1.4, or 1.5 bar (where it should be in theory) my boost spikes all the way to 1.9 bar and then settles again. So I've set it up with a majorly low set gain to try and control spiking at the expense of driveability.

My high boost is set up more conventionally but is still tricky:
set 90
gain 5
set gain 1.85
peak boost 1.99
limiter 4

With these settings, form WIT at low rpm the car spools fine but spikes up to just over 1.9 and then settles at 1.9 and slowly tapers to 1.8 by redline. But again, from part throttle, it tends to spool, spike up to 1.9xx, bounce down really briefly to 1.7/1.6 etc. briefly before settling and holding at 1.9, tapering to 1.8.

No idea what the problem could be - seems that having my set gain value set to anything above 1.0 bar gives me a spike to 1.9 and then down to whatever I want to hold (regardless of my set value, which is how far the WG is supposed to open). Otherwise, if I put my set gain value artificially low I get a hesitation at 0.9 bar form part throttle (ie under normal driving).

I've been thinking of swapping the EBC for an MBC because it's annoying as heck to drive. Didn't used to do this before my turbo/injector swap and the mechanics swear the EBC is hooked up correctly.

Annoying! Any EBC experts out there who can diagnose this!?