Still can't boost above stock level...

[unwrittenLaw]

Ever since I went to the dealer about a month ago to check out a CEL, I have not been able to get the boost past stock. I've checked the lines, tried 2 different MBC's and still no luck. I can't get a good look at the wastegate, but the line from the T to the wastegate looks normal. The dealer did something to my car and its pissing me off. I can't really go back and ask them why I can't boost past normal level, so I don't know what to do...
Did they adjust the wastegate or something else?
I'm just really frustrated...any suggestions?

 

[boostisgood]

You cant adjust the wastegate like that. If they put in a different spring, it will open at a different PSI.

What a Boost controller does, is bleed off some of the Manifold pressure, being sent to the Wastegate, to trick it into seeing the predetermned PSI.

I would suggest getting your hands on an EBC. IMHO, the price difference is MUCH worth it.

 

[II-Savy]

http://www.boostcontroller.com/alert.php


Maybe this one would help....it looks nice and it seems to be solid. I have no deep knowledge at all with these but maybe more fine tuning with the controller is what you need.

 

[jred321]

what does your vacuum read at idle? and have you tried doing a leak test on the at the turbo to make sure there are no leaks? i mean by hooking up a rubber tube to the intake side of the turbo and using pressurized air to fill it, watching your boost gauge and listening for leaks.

 

[unwrittenLaw]

At idle it reads like -70 to -80 hkpa, which is what it read before I had problems The boost readings seem fine, it holds boost at about .36-.38 under load. The pressure seems steady so I don't think I have any leaks but not 100% sure. I haven't tried doing a leak test..I can't get to the turbo very easily. I'm going to a different dealer next week to have them look at it. I told them that its not boosting as much as it used to. Its just strange that my mbc was working fine before I took it to the dealer, and now 2 different mbc's wont raise the boost one bit...

 

[unwrittenLaw]

You cant adjust the wastegate like that. If they put in a different spring, it will open at a different PSI.

What a Boost controller does, is bleed off some of the Manifold pressure, being sent to the Wastegate, to trick it into seeing the predetermned PSI.

I would suggest getting your hands on an EBC. IMHO, the price difference is MUCH worth it.

Could they have put in a new spring? I was there for about an hour or so...but I was watching them for some of the time, and it didn't seem like the tech was doing anything major. But I don't know how hard it is to change out a wastegate spring...

 

[unwrittenLaw]

I checked for leaks by covering the intake, and it stalled out...so is it pretty safe to say they're aren't any vacuum leaks?

 

[jred321]

i would say that's safe to say, and changing the spring shouldn't make a difference when turning up the boost, just turning it down, since the pressure is bled off, so i'm out of ideas as to why you can't turn up the boost if everything is how it should be.

 

[chinkysuavo]

were u able to boost higher b4 u had the CEL issue? And, did u remove the MBC b4 taking the car in? Could it be one of the lines from the MBC are loose?

 

[unwrittenLaw]

Yeah, I was able to boost higher before the cel came on and after. But the next day I took out the mbc before I went to the dealer. I waited a couple weeks after I went to the dealer to put the mbc back in and thats when the problem started. The cel hasn't came back on since I got the reflash though, so I think it was just a fluke or something. And I've checked all the mbc lines, and like I said, I've also tried 2 different mbc's...

 

[unwrittenLaw]

Well the CEL came back on again today while I was driving on the highway...I wonder if whatever is causing the CEL is also restricting the boost...

 

[chinkysuavo]

hmm, is ur intake temp sensor connected and seated properly? i know that will make the CEL come on, or it could be an exhaust leak, check around the O2 sensor after the 1st cat...other than that, I'm stumped bro.

 

[jred321]

what is the cel for? get it scanned at like autozone or wherever does it for free because they could be related.

 

[unwrittenLaw]

Well when I first went in to the dealer for the CEL, they couldn't pinpoint it, but said they had a 'boost concern' which they thought might have affected the Variable Tumble Control System (VTCS). But they wanted me to comeback and leave it overnight so they could test it cold..I never went back because I didn't trust them. Then the CEL went away for awhile and now its back, but I'm going to a different dealer to have them check it out this time, and hopefully they won't have a "boost concern"...i hate dealers..

 

[unwrittenLaw]

Update:

The CEL was fixed..seems there was a blockage in one of the check valves in the VTCS (variable tumble control system). So they put in a new check valve..the CEL did come back on briefly but hasn't lit up for about a month now..so I think its ok.

But, I went out and re-installed my Joe P MBC, checked all the vacuum lines, adjusted the MBC...and started driving. And once again..I can't get above stock boost...I don't know what could be causing this...anyone have any ideas?

 

[Dexter]

youre 1000000000000% sure you are installing it correctly?

 

[unwrittenLaw]

Yeah, I've uninstalled/reinstalled a lot and even tried a different boost controller...its like its not even there..no increase in boost, although it does seem to spool up a little faster according to my Blitz DTT/Guage

 

[Aricjm15]

install the boost controller as close to the waistgate as possible, directly to the line coming off of the waistgate, there should not be ANY hose T's between the MBC and the waistgate

other than that I have no clue what it could be

 

[unwrittenLaw]

Yeah, the place where its installed is as close to the wastegate as you can get, its on the line directly from the wg...

 

[MazdaDryvr]

I dont mean to thread jack, but when you said...

but said they had a 'boost concern' which they thought might have affected the Variable Tumble Control System (VTCS).

Did the dealer explain what this system is? I have my MSP at 9psi with JoeP MBC and I have been wondering if the extra boost will affect the car. They never reset my ECU and I wonderd if that should be done?