ok well i was driving my car and made it about 2 miles up the road when it backfired then started knocking.the weird thing is it only knocks when i give it gas, and it sounds like its in the top half of the engine...it is a very loud definite knock.does any one know what happened?
thanks tyler

 

How's the oil pressure, engine temp? Check the timing. Sounds like a HUGE vacuum leak occured causing it to lean out really bad leading to severe detonation. Check the simple stuff first: Timing, oil pressure, vacuum hoses, etc. Report what you find and we'll go from there.

 

yes check those

if those are fine i suggest taking the valve covers off and checking the rockerarms, thats what was wrong with my 95 2.8 when i got it

 

I would guess your timing is to high. Have you changed brands or grade ofgas recently?

 

If it happened suddenly, I'd guess a either a vacuum hose popped off or broke, or a part of your fuel system has clogged or failed. Any loud hissing from under the hood?