The vehicle is a 1993 FD3S R1 trim. My check engine light has come on briefly then gone out a few times the last few days. I connected TEN to GRD to read the codes the way you are supposed to but the light doesn't seem to flash the codes the way it's supposed to. Instead of flashing codes and repeating or having no light for no codes the light comes on for a second or two then goes out for a second or two, then comes back on and remains light from that point on(it does not repeat). What could this mean?

 

try this:RX7 FD and Series 5 Error Codes

 

I know how to read the codes, the issue was/is that the computer isn't saving them after the ignition is turned completely off for some reason. My check engine light came on briefly again today on the way home from work, this time I had a jumper wire handy in the car so before I turned the car off I connected my jumper wire then cycled the ignition from run to accessory back to run and pulled a code 11 intake air thermosensor. When the ignition was moved from run to off then back to run the code was gone and I only had a solid light again. I don't know why it's not remembering the code, but at least I have my code now.

I'm pretty sure it's just a loose connector as I believe the connector for the thermosensor has a broken release tab. I'll have to take some electrical tape and tape those pieces together so they don't move.

 

If it helps to confirm, a bad IAT sensor causes the car to run rich. Going down the road I noticed a loss of power and the occasional puff of black smoke.

FWIW, the stock location of the IAT under the intake manifold lends it to alot of heatsoak and it's a PITA to deal with there. Many of us have done a simple relocation to the intake elbow, just upstream from the throttle-body. Rather than removing the UIM, you could just unplug, extend the wires, get a new IAT and leave the old one in place. Way less heatsoak, and easier to address that broken connector too.