Please Help???

[dsm726]

Alright, i got my car back from the tranny shop finally and the oil return line was cracked again so i had to wait for that and after about three more weeks i got that on. My car has been sitting for a good four months. I got in it yesterday after having changed the oil, plugs, wires, and coolant. It idles great but when i start boosting over 10 lbs it will buck crazily and feels like im hitting a brick wall sometimes . The boost stays at the same psi, set at 14, but the car will boost and buck, boost and buck. could someone tell me what could be wrong. When under no boost it runs like a champ, but under boost it is horrrible and i dont want to mess up the engine. Note, when it bucks it looks like a huge cloud of BLACK smoke coming out the back, but i dont really know if there is some white in there and if im detonating.

 

[blackGSX2g]

Do a boost leak check and make sure your plugs are NGKs and gapped to .028''. The black smoke means your running too rich.

 

[T2Small]

You are probably hitting fuel cut early because of a boost leak. The MAF is reporting an airflow value that is too high, and the ECU cuts fuel entirely for an instant causing your bucking. The black smoke (excessively rich) points to the same conclusion.

 

[dsm726]

I did a boost leak test and it was clean, no leaks. it turns out i was running a little lean and my car recognized the knocking and slowed down the timing. I figured out what happened. I realized that one of my evaporative canisters had a big hole in the top of it and there were vaccuum lines coming from it. One of those was coming from some fuel source because when i plugged the both of them, the problem went away. I think there wasnt enough pressure in the fuel line because of that leak from the unplugged hose, when i hit high boost there was no fuel, and it just retarted the timing.

 

[gurmanator]

I blew the line off my wastegate and it did the samething(vaccum line).Its an idea??