ok today i started my car and all of a sudden i have no oil pressure or the guage is not working how can i foind out if its my guage or the oil pressure ??

also where is the oil pressure sending unit on a 1988 rx7 with b13

 

first see how much oil you have. if you have no oil, then you have no oil pressure for sure.
if you have enough oil, then you could have a bad oil pump, bad sender or bad gauge, or or bad wires from the sender to the gauge, or some kind of blockage so no oil gets to teh part of the engine where the sender is. or any combination of those.
the sender is just below the oil filter.

 

as drewl said, check the connection at the sender. that is the most common failure and can be easily overlooked. make sure you have a good connection. then if you do, test to see if you have 12V at the connector when the key is in the accy position. start there and post back.

 

Oil pump on rx7's hardley ever fail!

 

In FBs and FCs yes, but I've been hearing alot about FD oil pumps sheering the key inside the pump resulting in major bearing failures. This coming from well known rebuilders.

 

Pressure sender...

 

what is the best way to remove the sending unit....im installing a new oil pressure guage because the whole unit thats currently in the car does not work.....

 

Use a 10mm open end wrench on the shaft of the oil pressure sending unit.