Don't rip into the oil pump until you are sure it is bad. It's a big job. Check pressure with a mechanical gauge. Most parts stores will lend or rent them. It screws into where the oil sending unit goes. I would hate to see you rip half the engine apart to find you needed a 20 dollar sending unit. Keep in mind, if there is no knocking or ticking from the engine, you have oil pressure.
As far as the other problem, if you had the battery disconnected for a period of time, it will take the computer some miles to relearn everything. And the idle issue, check for vacuum leaks and check the idle air control valve (IAC). It is responsible for the idle speed.
One last thing. To remove the waterpump is a pain. I know you had to remove the AC compressor and alt as well as their mounting bracket. I hope you replaced the bypass hose under there. Also, the temp sending unit is mounted next to the heater hose right there. Check to make sure you didn't break it. It is small, and can break easily. That could have an affect on driveability.
Friday, February 25th, 2011 AT 2:37 AM