i have a 98 dakota with a 5.2 with headers larger throttle body and underdrive pulleys. i had the gaskets in the engine changed it originally came out of a 96 and everything leaked but anyways it ran really good wen i pulled it wen i got it back and put it in it runs no where near as good.ive changed the plugs wires cap and rotor still not right. if u hold it aroung 1300 rmp it misfires pretty bad but after that its ok. and wen i give it alot of gas it sounds like its goin but its really not that fast. the truck this engione came out of was fast i just want it back plzz help

 

Could it be a computer problem?

 

Look at the things that changed besides gaskets.

 

ive tried a new computer it runs the same. and the only thing i changed from before was the throttle body and i put headers on it other then that it was the same.

 

You said it ran good and then "you pulled it and when it went back in it ran like crap" or something to that effect, correct?

Now, this may be a pain the ****, but before you start throwing parts at it, you need to make sure that everything that was disconnected when the engine was taken out is properly re-connected. Also, you might want to make sure that you don't have any broken wires / harnesses / vacuum lines.

I guess my point is that it seems more likely that something is not properly hooked up than that something unrelated to pulling the engine died on you. You tried a new computer, even though presumably you didn't even touch it. But, have you physically touched and inspected everything that you did touch?

I don't want you to think I think you're a dimwit or anything, so if you have already done this, please don't take it personally, but you didn't indicate that you did anything other than cap, plugs, wires, and computer. I am pretty sure that there are many more things removed / disconnected and re-installed / re-connected than just these. Seems cheaper to start there as opposed to jumping off to some tangent.

 

i will double and triple check everything will get back to u thanks for the help

 

throttle body and headers???