why is it when i hit a bumb in the road kinda hard my car acts up and sputters . then sum times ill be crusien going 30 and the speed o and tach wiht jump up then back. then maybe 5 mins later or next bump itll do it again.?? let me know whats going on.

 

sounds like the ground on your thermostat housing is loose

 

or the main relay is acting up.....

 

Id bet my money on the ground wire on the coil is loose it's what sends signal to tach and if it's a crappy connection your car would run like crap also...