Has anyone else had this problem with their mk3?

[msupra91]

ok so i'm new to the forum and have had my mk3 for a little over a year now, since buying it i have replaced the engine with an imported jdm one with roughly 45k miles on it. It's a 7mgte. The issue i'm having is sometimes when i start off in first gear and really floor it the car bogs way down and jerks violently until i let off the gas, then car goes back to drive normally. I've replaced the MAF thining that was the problem but it still does it sometimes, this also happened with the original engine, but almost everything has been replaced since then mechanically wise, so i'm stumped...Any ideas??

 

[pimptrizkit]

fuel cut most likely, check all your hoses for a leak.

 

[crazysupra2JZ]

fuel cut is what you're experiencing.... check your wastegate, vacuum lines and check for boost leaks.

 

[johnathan1]

Yea, sounds like fuel cut...you likely have a boost leak...

 

[msupra91]

What sorts of things can i do to see if i have a boost leak? Also could the intercooler be the culprit? possibly cracked or something?

 

[steven89]

make a boost leak tester.. uhh.. theres a writeup of it somewhere around here.

I know it involves a home depot rubber reducer, a plumming cap, and a air compressor fitting, and a air compressor.

 

[msupra91]

alright i might have to try that out sometime. the only thing is all the hoses ect were replaced with the new engine. the only thing still original to the car is the intercooler..

 

[MA70Snowman]

http://www.supramania.com/forums/showthread.php?t=19718&highlight=boost+leak+tester

hope that helps.

 

[msupra91]

Just wondering..could it be possible that the IC is causing this? possibly a crack somewhere in it? I dont ever remember hearing a boost leak or anything. I plan on installing a new FMIC and hardpipes as soon as i can anyway i just need to take it in to get the hardpipes made.

 

[Supracentral]

Anything in the intake path between the AFM and the turbo, or between the turbo and the surge tank (intake manifold) can cause this. So yes the IC could be the culprit, although it's most likely:

1. The rubber hoses.
2. The plastic elbow in the passenger fender.
3. A loose hose clamp.

Most times you can't hear a boost leak.

The most common is a hole in the hose that comes out of the turbo and connects to the metal elbow.