I've got a 1996 3.0L that started losing coolant. No leaks, no water in the oil. So I decided to check the heater core. After getting everything back in, the engine idles real rough and has some backfire to it. I put new plugs and wires on it with no improvement. I had the battery cable off for several days. Could it have wiped something out when I hooked the battery back up? I see nothing wrong with the wiring or vacuum lines. HELP!!!