87GT006

I own a 87' 5.0 GT and I have had the car relatively long, basically since it was about at 40,000 miles. recently, I have been having this problem with sort of a backfire when I hit the throttle. The car is relatively stock. so I cant see it being anything performance related. I have knocked my head around this problem for about 3 weeks now and it almost makes me sad when I go to hit the throttle, and the car gets to about 3,000 rpms and than it suddenly hold back power for a second and than kicks like a mule forward . I ahve debated if it was a fuel delivery related problem or simply a lack backpressure somewhere in the exhaust. To better describe what happens, lemme try this.

"I am cruising around town, casually changing gears around 2500-3000, and than I feel the need to get on it a little, so I figure I will rev out 1st for a little extra noise and head nods. So I hit the pedal, and the car shoots to 3000 than it feels like the car basically ran into a sand pit for a second, and than suddenly jets off similiar to the backfire somewhat. " (no actual backfiring) . It really sucks when you dont know when this is going to happen, and my 10+ years of mechanical savvy cant seem to grasp it. has anyone else had this problem or know how to deal with it? any suggestion or help would be appreciated.

-Verd