[RESOLVED] 2g bucks hard under heavy acceleration

[miller97tsi]

i have read all of the threads posted about this and stilll havent gathered enough to narrow what my problem can be. when i am driving regular i have no problems but when i put it to the floor about 4500 to 5000 rpm the car takes a hard nose dive, it makes a loud thud noise let off the gas and everything is fine. what could be the problem? i have little mods and i am confused. could the fact that i have an after market bov not recircted or what?

 

[Defiant]

ok so good news i recirced it and it doesnt buck hard anymore.

Yet again, do not vent the stock DSM intake system.

 

[No_Skillz]

Why wouldn't it contribute to fuel cut? I've had someone tell me something similar but I don't understand??? How is it different than a boost leak since it's lost air counted by the maf?

Fuel cut occurs when you are on the throttle, the motor is making lots of power, and the ECU thinks there's too much air going to the cylinders and shuts off fuel supply.

BOV is vented to atmosphere does not contribute to this because when it blows off, the driver is already off the throttle and fuel is cut because the motor is in a powering down scenario, the throttle plate is closed, and there is nowhere near enough air going through the MAF. The ECU is powering down the motor, not saving it from blowing up. However, it will run rich at this point, just like how you will run rich under boost if you have lots of boost leaks.

 

[habitatguy187]

Fuel cut occurs when you are on the throttle, the motor is making lots of power, and the ECU thinks there's too much air going to the cylinders and shuts off fuel supply.

BOV is vented to atmosphere does not contribute to this because when it blows off, the driver is already off the throttle and fuel is cut because the motor is in a powering down scenario, the throttle plate is closed, and there is nowhere near enough air going through the MAF. The ECU is powering down the motor, not saving it from blowing up. However, it will run rich at this point, just like how you will run rich under boost if you have lots of boost leaks.

Makes sense thanks and good job explaining that.

 

[miller97tsi]

last one, when you say stock intake system do mean ecerything including stock intercooler and piping to the actual air intake. and when is it ok to vent the bov or should it always stay recirced until the gm maf is installed.

 

[habitatguy187]

Stock intake usually just means the intake pipe. (not always though i.e. intake manifold, tb, intercooler piping ect.) And yes it should always stay recirculated until the gm maf. You can still buy an aftermarket bov that makes the sound you're probably looking for though.

 

[No_Skillz]

Stock intake SYSTEM usually refers from air filter to cylinder head.

An alternative to running a GM MAF is to convert to speed density.