I have a 96 with about 149k, the car runs great up until the point it gets hot. When it does this i will stop at a stoplight and go to take off and the car will hesitate or jerk. I have taken it to a dealer and they said i had a crack in my block, but that was 15,000 miles ago. I have a buddy who said it might be the fuel pump. If anyone has any ideas on this please i need help am trying to move so i need to get it fixed bad.

Depending on how many miles are on them, I'd try a new set of AC Delco OEM replacement plugs and wires for starters. These engines are fairly sensitive to ignition troubles. There are literally dozens of threads where that turns out to be the issue. I'd be leery of using aftermarket stuff (Bosch wires, ect), as there are posts along THOSE lines too.

I wouldn't buy AC=Delco plugs, they are poor quality, instead buy NGK Irridium plugs. Mine runs great with them and gets 22-26 city/hiwy mileage with an extra 500 pounds lift I have tied to the back! which is great for a 4700 pound car (including me). Try NGK you'll lovem

I dont think it is an ignition problem it only does it when you take off from a stopped position and it goes for about 5-10 secs. then quits. And it only does it when the car has been driven under extreme conditions. it is baffiling me, but i might try the plugs and wires, i am running bosch +2 in mine with bosch 7mm wires, i have had them on there for about a year and a half. But i did drive it for about 300 miles today and got 29 miles to the gallon with it.

Yeah, that doesn't sound quite right with your good mileage and all. I guess you could probably take the parts back if it doesn't work though.

My misfire troubles did start only under really specific conditions (~2000 rpm just after it shifted into 2nd and gently accelerating). It'd go away if I romped on it, but it also rapidly got worse over about a month until it was painfully obvious it was misfiring.

well if youi get anymore ideas let me know please