New RX7; Low Idle.
 

Okay, so two days ago I purchased a 1990 rx7 that had beautiful paint, and seemed great upon purchase; it ran fine from what I recall. I paid $2600 just for your curiosity. Honestly, it is a beautiful car and I have been trying to restore the car to the beast that it can be.

It has seen a bit of abuse and had very low oil so I have changed the oil and oil filter; also fixed the broken door handle (driver's side.. ugh), working on shifter bushings and maybe some gear oil.

But lately, the car, on start-up, will idle at really low, like 100-500 rpm and sputter; after a few minutes it usually goes up to 750 rpm. It drives fine and runs strong when being driven but will idle really low sometimes while in neutral when stopped in traffic. The shifter even shakes from the hesitation and sputtering sometimes.

Today I checked the plugs and one was loose and two burned (I have new ones ordered coming in tomorrow).

Anyways, can anyone inform me as to what my issue could be and what are the first steps to tackling this problem? (I have read a few guides for this issue but I wanted to give specific feedback and perhaps receive a more direct answer as to my issue).

whats your compression look like?

Replace the plugs first and see if that fixes the problem or not.

I have not checked that yet. I will soon buy a compression test kit and do that.

First the plugs will be changed, maybe the wires, and I'll inquire from there.

So I have changed the plugs... the previous owner did not properly change them as the leading and trailing plugs were swapped on one side. This made it idle much better but it is still idling low so it may have some compression issues.

If it idles below 750 w/load on the engine then check the BAC. The role of the BAC is to prevent the idle from dropping below 750 rpm except for the briefest of moments.