I have an 87 Mustang GT, just purchased a few weeks ago. It had a big autometer tachometer I was not a fan of so I decided to take it out. I disconected the battery and due to the way it was wired I had to take the gauge cluster out. While I had it apart I decied to clean it up a bit so I took off the plastic cover of the intrument panel and cleaned all of the gauge cluster which was a mess, in the process I did hit the oil pressue needle by accident, but it dropped back down to where it was before I hit it. I took out the wiring for the autometer tachometer, and re-connected the stock wiring where it was spliced for the autometer tachometer (one wire was spliced into a crane cam ignition coil).
I put everything back together and took it out for a drive. Drove for about 10 min and everything was fine. On my way back home coming to a stop, the oil pressure gauge drops down to almost 0, the amp light comes on, the low coolant light comes on, and check engine
light comes on, then the car stalls. Start it back up and the oil pressure is reading very low. Same thing happens coming to the next stop sign except I kept it from stalling. Get it back home in the garage and shut it down. I check things out, disconnectd the oil pressure sending unit and connect it again and start the car up again. The idle is all over the place, surging up and down almost stalling each time. The oil pressure reads in the middle but also drops up and down with the idle.
I know the car has to 're-learn' after the battery is disconected but I had disconnected it before to install a stereo and had no issues after starting it up again. What are your toughts on the oild pressure, is it just to gauge or could I have an oil pressure issue? Is there anything else that would need to be done to re-set the idle after disconecting the battery? I do have underdrive pullies. My biggest fear is the oil pressure, any easy way to accurately check this? The engine was just rebuilt 5000km ago.