boost problem

[geturdone327]

hey, i recently got my car on the road and i isntalled an aftermarket mbc. i dont know if it was doing it before but when i floor it sometimes my car will make a loud pop and it will lose its power and jerk for that moment.

it even did it with the mbc turned down so am i running to much boost? is that compressor surge or is my bov having a spaz or what? sometimes it does it very bad its startling.

has anybody had the same experience or know what may be causing the problem? thanks

 

[bryanwheat]

Do you have a boost gauge to monitor how many psi it is running? Sounds like fuel cut from running too much boost.

 

[geturdone327]

Just the factory one I was trying to find a nice one with a podto put it in on ebay but no dice so far. Thats was what I was leaning towards. Too much boost for my injectors? Or not enough put out from my fuel pump

 

[bryanwheat]

Take the boost controller off and hook the factory solenoid back up until you get an aftermarket gauge. The stock gauge is not accurate at all. You will destroy your engine doing things like this. Fuel isn't caused by over running the injectors or pump. It happens when you pull more air thru the maf than what the ecu is designed to compensate for.

 

[geturdone327]

Ok. Im new to turbocharged vehicles haha I havent driven it since then ### I didnt want to wreck anything. Once I get a proper boost gauge hooked up how much psi do you think I can safely turn it up to on the stock system

 

[bryanwheat]

Ok. Im new to turbocharged vehicles haha I havent driven it since then ### I didnt want to wreck anything. Once I get a proper boost gauge hooked up how much psi do you think I can safely turn it up to on the stock system

I wouldn't go any higher than 14 psi without a way to monitor for knock.

 

[Labryth]

What is knock, and how can we tell if we are running too much boost?

 

[bryanwheat]

What is knock, and how can we tell if we are running too much boost?

Knock is another word for pre ignition or detonation. It is what happens when you run the engine too lean, run too low of octane, or run too aggressive of timing. You will be able to tell if you are running too much boost first by using a gauge, second by monitoring knock, air/fuel ratio's, and injector duty cycle with a data logger and wideband a/f gauge.

 

[MiroDSM]

Go to an auto parts store and at least get an auto meter boost gauge they are like 60 bucks. Hope your engine is ok

 

[eSCAPEist_]

Not compressor surge I know that.

 

[RayBan GST]

start with the basics and do some reading there are a lot of info on MBC and the boost gauge , you dont increase boost just like that , boost gauge is a must and also i hope you hooked up that MBC correctly.

 

[geturdone327]

It drives fine before and after it does that only when I accelerate really fast it did it. The motor doesnt have a factory knock sensor? Sorry like I said im new to these I know more about oldschool cars haha but I love to learn about this Its an awesome car

 

[bryanwheat]

It drives fine before and after it does that only when I accelerate really fast it did it. The motor doesnt have a factory knock sensor? Sorry like I said im new to these I know more about oldschool cars haha but I love to learn about this Its an awesome car

The engine does have a knock sensor.

 

[geturdone327]

Ibreally need to learn more about this kind of stuff haha but yes the mbc is correctly hooked up and I left the old section of hose that has the restrictor in it and replaced the rest

 

[bryanwheat]

Ibreally need to learn more about this kind of stuff haha but yes the mbc is correctly hooked up and I left the old section of hose that has the restrictor in it and replaced the rest

What do you mean hose with a restrictor? Also if you turned the mbc down all the way and it didn't drop down to wastegate pressure (10ish psi) than you either have the controller hooked up wrong or it is defective. Regardless don't drive it or reinstall the oem setup until you get a boost gauge.

 

[geturdone327]

There is a little ball thing inside of one of the vaccum lines. I think its the one from the turbo to the t splitter. I havent driven it since, but I will hook up the old stuff tommorow, thanks

 

[bryanwheat]

There is a little ball thing inside of one of the vaccum lines. I think its the one from the turbo to the t splitter. I havent driven it since, but I will hook up the old stuff tommorow, thanks

There is no restrictor in the vacuum lines from the factory. The is a part called a restrictor in the boost control solenoid, but it is just a tube that makes the inside diameter smaller.

 

[geturdone327]

If thats the case then its not factory even though it matches everything else because I can feel the ball in the line. I didnt even know about it until I looked up instructions on how to hook the boost controller up and it showed the ball and they called it a restrictor with a narrower hole threw it

So is what was occuring was a really bad backfire?