my car has been running great up until last week all i did was change the altanator and know it will not rev above 3 or 4 thousand. I think i got bad gas becouse my truck is doing the same thing. i was just woundering if bad gas will couse this? the car runns good going down the road until you try and run it hard and get into boost. but i havent changed anything it just started acting up. also my fuel preasure at idle is almost 40 psi and with the cacume lines off it goes to about 44 or 45 psi. i could not tell you what it does under boost becouse it will not rev and build alot of boost to tell. it just sound like it is missing and loading up. also no ses. any ideas??

Thanks
Shane