Boost Creep (oldman read this)

[~laser_craver~]

I have a boost creep problem. Its weird i took the cat out and put in a testpipe, and i had boost leaks so id hit fuelcut prematurely. So i fixed those and it ran perfect all the way to redline for a whole day. Then the next day it started to creep and i never changed anything. So i ported it and it didnt help. So i made a external dump for it and that didnt help. So i ported the hell out of it following the vfaq. And it still crept. And so i put the cat back in there today and it still creeps I dont know what the heck to do.... Its really pissing me off.

Any help for a frustrated DSM'er?

 

[daren_p]

Is this on an evoIII? What kind of boost are you trying to run & what is it creeping to? Does it creep in every gear? Have you checked the WG actuator to make sure thats its functioning correctly?

 

[mirkoelek]

I have a boost creep problem. Its weird i took the cat out and put in a testpipe, and i had boost leaks so id hit fuelcut prematurely. So i fixed those and it ran perfect all the way to redline for a whole day. Then the next day it started to creep and i never changed anything. So i ported it and it didnt help. So i made a external dump for it and that didnt help. So i ported the hell out of it following the vfaq. And it still crept. And so i put the cat back in there today and it still creeps I dont know what the heck to do.... Its really pissing me off.

Any help for a frustrated DSM'er?

it could be you boost controler... Get the External wastegate if you have money to spend and electronic boost controler...

 

[~laser_craver~]

I have the wastegate running its preset setting no boost controller at all. And it will creep in all gears currently unless i only give like half throttle or so and then itll hold at 10 psi. But if i floor it, the boost just hesitates at 10 then slowly goes upt ill around 18 and i hit fuelcut. But when i hit fuelcut it will only cut out breifly then get back in it. I havent test the wg actuator.... Its a brand new turbo. And its a b16g from slowboy.

 

[daren_p]

This is very strange considering its a reg b16g which aren't known to creep. I would defently get the WG actuator checked and make sure the flapper can be moved freely with th actuator disconnected. Have you ever tried setting your boost at a higher level, maybe try 16 psi and see if it creeps the same. Have you tried checking for boost leaks again after it started acting up?

 

[~laser_craver~]

Ill try running a boost leak test tomorow..... Ya whats really weird to me is that it was totally fine for a whole day driving all over the place. And then all of a sudeen it started to creep. And i never touched anything. All i did was park it and close the garage door....

 

[mirkoelek]

Ill try running a boost leak test tomorow..... Ya whats really weird to me is that it was totally fine for a whole day driving all over the place. And then all of a sudeen it started to creep. And i never touched anything. All i did was park it and close the garage door....

why would you run boost leak test..... creeep means you have more boost than you need

 

[daren_p]

why would you run boost leak test..... creeep means you have more boost than you need

Because he's hitting fuel cut...

Was just wondering where is your MBC sourced from? Have you checked the lines to the WG/MBC and have you tried bypassing the MBC to rule a problem with it out.

 

[mirkoelek]

Because he's hitting fuel cut...

too much boost, not enough fuel... maybe knock and detonation... the guy has stock injectors

 

[~laser_craver~]

i have the line running fromt he intake manni to the bov with a t in it to the wastegate actuator. i had it going thru the mbc then the wastegate but i just unhooked the mbc all together. but yes i have stock injectors and pump and everything. i do have a maft setup tho... should i try taking the wag arm off and seeing if it still creeps? and how much?

 

[daren_p]

too much boost, not enough fuel... maybe knock and detonation... the guy has stock injectors

Fuel cut is caused by over running the MAF, not with lack of fuel. But the easiest way to slove the boost creep issue is to upgrade the fuel system and run 20 psi daily, problem solved .

This shouldn't be an issue because if it worked fine one day it should be able to work fine again but are you still running the 1g O2 sensor housing? Has it to been ported and did you work on the WG passage?

 

[daren_p]

i have the line running fromt he intake manni to the bov with a t in it to the wastegate actuator. i had it going thru the mbc then the wastegate but i just unhooked the mbc all together. but yes i have stock injectors and pump and everything. i do have a maft setup tho... should i try taking the wag arm off and seeing if it still creeps? and how much?

So you get the same creep with the MBC hooked up and the pressure source running directly to the WG? T-ing into the bov line is not the preferred source for the MBC, its best to tap into the lower ic pipe. Yes I would disconnect the actuator and see what kind of boost you hit then.

 

[gSx_r1der]

if when you are driving you are just boosting to infinity, I had this same problem when running my wastegate strait to the boost source. I had to actually put pressurized air through the wastgate to ensure it opened up under boost and once I did this I assured my wastegate was opening up under boost and hooked everything back up and voila. So itsi apparent that somehow my wastegate was not opening.

 

[mirkoelek]

Fuel cut is caused by over running the MAF, not with lack of fuel. But the easiest way to slove the boost creep issue is to upgrade the fuel system and run 20 psi daily, problem solved .

This shouldn't be an issue because if it worked fine one day it should be able to work fine again but are you still running the 1g O2 sensor housing? Has it to been ported and did you work on the WG passage?

i wasnt talking about boost creep, i said fuel cut could be because he has stock injectors

 

[~laser_craver~]

When the mbc was hooked up it did that same thing i only un hooked it to see if that would help with the problem because i remember hearing somewhere that someone was creeping because of their mbc or something like that i dont remember exactly what. But ya i do have the stock o2 housing. But i made it into an external dump..... Whic only heled a tiny bit..... And made the car 100 times louder

 

[Turbocharged]

Disconnect the WG arm. If you still have boost creep after that, then the problem is with the WG flapper size (you do have an external dump right?). Do you have the standard 31mm gate or the 34mm gate? Either way, an external setup is definately not needed for that small of a turbo.

 

[Turbocharged]

Also, make sure that the WG flapper can open freely without hitting the O2 sensor housing. Ive had that problem before...

 

[NOSLO2PT0]

Port The Wastegate Hole!!!!!!!!!!!!!!!!!!!!

 

[gSx_r1der]

Also, make sure that the WG flapper can open freely without hitting the O2 sensor housing. Ive had that problem before...

exactly what I said, apple pressurized air to the wastegate and see if it opens.

 

[daren_p]

i wasnt talking about boost creep, i said fuel cut could be because he has stock injectors

Neither was I, they were two seperate statements, just put in the same paragraph. Like I said fuel cut has nothing to do with fuel or stock injectors. It happens when the MAF see's too much airflow & thats why I origionally said to check again for boost leaks. Boost leaks casue you to hit fuel cut before you should as some of the metered air is leaking out.

So are you still running the stock WG fapper size & hole? How did you turn your O2 housing into an external dump? ie does the exhaust gas still have to pass through most of the housing, if so has it been ported?

 

[unclesam099]

If I'm running with the WG arm off and I don't hit boost til just over 4000rpm and then go to ~20psi at redline, does that mean that I didn't port enough? Thanks!

 

[daren_p]

If I'm running with the WG arm off and I don't hit boost til just over 4000rpm and then go to ~20psi at redline, does that mean that I didn't port enough? Thanks!

Yes, if your WG actuator is disconnected then the flapper will just blow open. If you are creeping to 20 psi that means you need to either port the turbo (specifically WG area), get the larger flapper mod or port th O2 sensor housing (once angain the WG area)

 

[unclesam099]

Crap, I thought that I ported it enough. Well, I have to pull it off anyways to get a broken bolt out and put in helicoils, so I guess that I can keep going on it.

EDIT: Just put my WG arm on and it's holding rock steady to 19psi... at least til 6500rpm in 2nd, I ran out of road. That was with an open 2.5" tubular/dumped O2 housing. So I think that I'll be ok.

 

[dsmsucks]

Yeah oldman the peoples champ!!

 

[~laser_craver~]

Please dont post useless bs in here I dont want it locked Im trying to get help here.... Thanks


Ok. yes its the 31mm flapper and yes i made the hole a little larger. Sometime today or tomorow Im gettting a full 3inch buschur exhaust. So when i take my old exhaust off ill check the wastegate actuator.... When i ported it i made sure it opend atleast 80*.

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