86 325E??? no clue start issue. ignition swithc or WHAT

[BMW***325]

Hey guys , ive got an 86 325e and have been experiencing an issue with starting the car. I cant start the car with a turn of my key, when i turn the key the fuel pump runs constantly and i have to start the car by crossing the terminals on the inspection service port in the engine bay. I dont know what the issue is i cant figure out if its the DME, thermo swithces, or even just the ignition switch itself. The car also runs a bit rough

other issues that may be related
- temp gauge bobble around when warmed up
-car somtimes idles at 1200rpm

[ST1G]

Does turning the key to the start position make the starter crank?

[BMW***325]

It doesnt make the starter crank, and somtimes ill find that after the car has been running i can shut the car of and turn the key right after it shut off i can turn the key and the starter will move but not always turn the engine over, and will never work twice.

[ST1G]

What two pins are you touching together to get the starter to fire and the car to start?

[BMW***325]

its two of the pins that are located where you would usually reset your oil light, at the moment i have a momentary switch set up so im not arcing anything, but the only reason im doing this is because when i turn the key the starter doesnt turn. dash lights and fuel pump works so im a bit stumped