I have a 92 ford ranger with a 2.3. The motor has the 8 spark spark plugs. The problem I am having with it is when the alternator gets plugged in the truck runs ruff and wont stay running on its own and backfires when you keep your foot on the gas. The battery does charge when your foot stays on the gas. When the alternator is unplugged the truck starts, idles, and runs fine with no problems other than the battery does not charge.

What has been checked is the plug wires, coil packs, plugs, fuel pump, fuses, computer, sensors, the fuel pressure was between 40 and 50 when alternator is unplugged and then dropped to between 20 and 30 when alternator is plugged in, not sure why. Looked for wires in the engine bay for shorts anywhere didn't find any. So just not sure what else to try. If anyone has a question please ask and if you have any suggestions please feel free to share it would be very appreciated. Thanks