electric problem please help

[acesaines]

Hey guys I just got my 1993 celica sx and there is an electrical problem, when I hit a bump or back off the throttle the speedo and other dial fly up and down and it sounds like the ignition is turning on and off really quick, the car wants to die when this happens and if I accelerate when it's doing it it doesn't go and backfires, it happens ever time I hit a bump, back off or change gears,

Thanks for any help guys

[(mr2)]

Check all your leads and plugs to see if anything is loose.

Done any work in the engine bay lately? Battery, spark plugs etc??

[acesaines]

Okay thanks ill check, I only just got the car today so not sure what has been done to it, and what would make all the speedo, fuel, temp dial etc jump up and down