just swapped engines and i have a problem

[habajaba66]

ok, i just swapped engines and now i have a problem... its a 7afe engine and when i start it up, it runs fine, i can rfev it with no problem in park and neutral, i can hit the gas a bit in reverse, no problems, but when i put it into drive, it stutters and shudders when i try to accelerate . also, when it shudders, the engine temp spikes, although not all the way, just jumps a bit, and the check engine light somes on for a split second and then goes off... other than being really annoying, im assuming that this isnt great for the engine and i would like to know if n e one knows how to fix it... the engine has been timed to 10 degrees BTDC which is what the specs suggest and sounds the best to me.... if n e one know what i should do, or what may be wrong, please let me know... thanks in advance...

[fredk]

get the code out of it

[Pineapple]

Recheck all your connections, ground points, wires etc.