Had some loose solder joints on my Dakota ECM. You could tap it with a screwdriver handle and it would kill the engine. (probably the fuel pump) I put in a rebuilt one.
I have repaired video cards for computers, they get real hot when they are over clocked, Heat up your oven to 385, and let part sit in it for 20 minutes. The heat melts all the solder joints and repairs them. worked every time...