my truck randomly started idleing really rough. it will bounce between 400 and 1000 rpms and the whole truck will shake. it died on me in the middle of the road and the check engine light and battery light came on then it wouldnt start for about a minute then it fired right up but still idled rough. i would plug in a code reader but one problem....my OBDII port has a short in the wire and the fuse just blows every time i try to put a new fuse. thanks guys!

 

Is it doing it really bad just at idle? if so, you might have a massive vacuum leak somewhere. I know when i unplug my PCV valve hose, the truck just doesnt idle worth a dang.

 

Vacuum will do it also a head gasket or the pvc valve on top of the valve cover inspect all your hoses and go from their