So I have a 94 RX7 with a Power FC. I put a DEFI boost gauge on last night as well as an Apexi turbo timer. Now the car will not crank. I have power to everything dash, wipers, etc but the vehicle will not crank at all. It is not a dead battery and I know that I am getting power to the ignition switch. When I turn the key there is no starter operation. So I removed the turbo timer and still nothing. Is there an immobilizer on the 3rd gen, and if so is there a way to reset or relearn it. I disconnected the ignition switch harness put from the switch when i installed the timer. Is there a starter kill. Also I do not believe that it is the clutch switch because it worked fine before. Other issues that I noticed. This morning after I let it sit all night and tried to crank it, the car turned over once. Now it will not turn over again. Also the Power FC is turning on my exhaust over heat light. Doesnt that indicate a sensor problem or something. I forgot to write down what sensors are blocked out on the FC so I will take a picture and post it tonight. Any help greatly appreciated. Thanks.
AJ

 

An update on my situation... So after the car sat all day while I was at work... I come home put the key in and it cranks right up. So I let it run for a few and then I shut the car off. Then I try to crank again and nothing. Everything comes on like before but now it wont crank again....

 

Another update... So started doing some testing and voltage drops last night. Both the neutral switch and the clutch switch are working fine according to my PFC. Found that I have no voltage to the starter when cranking. Ends up that if I jumper the starter relay the car fires up just fine every time. Not sure if the relay itself is bad, I havent had a chance to test it yet. Its either the relay is bad or where ever the ground signal for the relay comes from. My schematic says CPU2 which would have to get its signal from the cluth pedal... im guessing. Ill try and do some more testing tonight.

 

look up your clutch pedal. you'll see the clutch switch. start pressir the clutch down, see if the rubber grommet that's supposed to push the switch in didn't come apart. happened to mine. i put a body panel clip in there, they don't sell the rubber thingy by itself, gotta buy the whole god damn pedal... :/

 

If you look at the Starter cut relay in the attached schematic, I was hoping that some one could tell me what CPU 2 is and what the LG/R is for and where it goes to. Here is a picture of the schematic.

 

does it even click or just not turn over? add another ground somewhere, won't hurt anything and it might be that, i had this problem when i relocated my fuse boxes and put a boost gauge on.

 

There is power to everything inside the car. There is power from the ignition switch to the starter relay. But for some reason the relay does not switch. Since I can watch both the neutral switch and the clutch switch toggle on and off on the PFC I can assume that they are functioning. I would just like to know where the CPU 2 wire is coming from so I can trace it. With the relay removed and a jumper wire installed between the ignition switch and starter it works fine.

 

As far as i know the CPU2 refers to a black box (usually marked as R110 or R100) which is situated in the drivers section beneath the steering wheel section. Basically this is a small ecu that controls the power windows, buzzer, dash lights etc.... My friend change this twice. Apparently its a common problem.

Hope this helps.

 

This is also known as FLASHER UNIT

 

did you check up there for that grommet for the clutch switch?

 

fwiw... When the starter went on my car, it was also very sudden. One day it worked. The next day it didn't.

 

wellhe says the relay's not "clicking" so something is not grounding it, it can be only 4 things, clutch switch, wiring issue (test by continuity,) or the grommet that pushes on the switch when you depress the clutch pedal to start it... or the relay failed.

 

can also be the ignition switch

 

The switch send the power to the relay. Both the clutch and neutral switch are switching also indicates that on the PFC. No clicking sounds. When you jumper the relay the car starts fine everytime. The battery is also fine and the starter too. I believe that the relay switching ground is not being triggered.

 

When you put in the turbo timer did you splice the wires or use the harness. If you cut them you may have some loose wiring. I believe there's also a ground wire under the steering column, did you disconnect any groung wires down there? Just a thought.