Car idles rough/black puff of smoke when i boost hard

[razey]

Hey guys,

Recently i have been having a few issues with my car.
When i start the car, it goes to about 1.5k then idles at about 600rpm, it will jump from 600 rpms to 700rpms and the engine will sound like it is running rough. As soon as i shift into reverse or drive, its an auto by the way, the rough idle goes away. I recently got the car dyno tuned and had my safc set. It was in about 30 degree weather at the time. It is now in the mid 70's low 80's here, could getting it tuned in the cold weather cause this? Any ideas?

Also when i boost i am getting a puff of blackish blue smoke out my exhaust. I have been keeping an eye on the oil and haven't noticed a drop.

 

[Talonman86096]

Boost leak test it step one. Black smoke is burning gas so your probably running rich. A boost leak will cause that.

 

[Talonman86096]

any oil in the coolant overflow? that would be a sign of possibly a head gasket i do believe.

 

[GMANS89GT]

if it were burning oil it would be gray smoke , coolant would be white . i would take it down and have it retuned for the less dense air temps . when you tune an engine for max performance it will smoke a little on a hard accel . its normal in most cases . it is working like an accelerator pump on a carb engine . and the rough idle would be from it running rich . what does the exhaust smell like ? fuel , oil , or coolant ?

 

[joeyzaza]

I am having the exact same problems. I replaced all my intercooler pipes with hard pipes. I put on new plugs and wires. I dont have a boost leak. Oil and coolent are fine. I seem to be hitting fuel cut in third gear, at 14 PSI. I am all stock except 3' turbo back exhaust, fmic, and a mbc. Mine is an auto too. My plugs are black, i replaced them with NGKs gapped right. I have searched everywhere. Any ideas????

 

[booostedGSX]

I am having the exact same problems. I replaced all my intercooler pipes with hard pipes. I put on new plugs and wires. I dont have a boost leak. Oil and coolent are fine. I seem to be hitting fuel cut in third gear, at 14 PSI. I am all stock except 3' turbo back exhaust, fmic, and a mbc. Mine is an auto too. My plugs are black, i replaced them with NGKs gapped right. I have searched everywhere. Any ideas????

Have you done a boost leak test? That is the only true way to find out if you have (or don't have) a boost leak. It can never hurt to test it.

 

[joeyzaza]

yes I did, thats the answere to most peoples problems. I think my turbo is going bad, and gumming up my o2 sensor. I dont have a CEL though. I checked for shaft play awhile back when I was fixing the boost leaks, and I didnt have any. Could this still be my turbo, I would love to have a good reason to buy a 14b.

 

[proto2]

Just buy it because you are losing alot of pressure through that FMIC on a T25. Blown seals are possible.