1998 Jeep Wrangler • 200,000 miles

I recently did a motor swap on my inline 6 wrangler, and used my old components from my previous motor that were completely fine when on the old motor. I rebuilt the motor and when I started it up, it began to accelerate off the bat, as if the gas pedal were floored, so I turned it off immediately. I then tried again and the same. I read online that a poorly seated intake or exhaust manifold could do this, so I bought a new gasket and bolted them both down securely. I know I have a severely clogged heater core, but would this cause such a high acceleration as soon as the car is turned on?
March 21, 2013.

Try cleaning the throttle plate with choke cleaner an dmake sure it is not stuck open. Cleanit on both sides as well as iac hole it may need to have the iac reset to idle down. Then check for a vacuum leak with choke spray, if rpm changes you found the leak and make sure all connections are good as well

Mar 21, 2013.