Tech area post: https://g35driver.com/forums/engine-...rt-clutch.html

Any advice would be appreciated.

 

I would suspect a faulty connection at or a faulty Clutch Interconnect Switch (E-121). This switch is actuated by the clutch pedal and is located by the pedal. Make sure the switch did't come loose and that it is being actuated by the pedal when depressed and released.

 

Thank you! I'll look into that and see if I can figure it out. Is there a "most-common" cause of failure in these? i.e. a loose connection that needs to be addressed, or a faulty switch that just needs to be outright replaced?

Thanks again,

 

I cannot comment on a common problem with this switch since my coupe is automatic. What I can comment on is the possibilities based on the circuit. Your pumping the clutch several times before it starts could simply be coincidence. In reality, there are quite a few items that could cause the problem you are having. I have attached a diagram identifying all possible problems in the circuit minus wiring and fuses.

1. Faulty clutch interconnect switch.
2. Faulty starter relay coil.
3. Faulty starter relay contacts.
4. Ignition switch.
5. Starter motor solenoid.
6. Starter motor.

Here are some things I would do before spending any money on parts. You can actually rule out 1 thru 4, if you you check for 12v at pin 1 of the starter solenoid with the ignition switch selected to start.

1. The Basics first, check your wiring connections going from the battery to your starter for condition, cleanliness and security.

2. Wiring at the clutch interconnect switch as previously mentioned.

3. You can bypass the interconnect switch by jumping pins 1 & 2 at the switch. Keep in mind that doing this is only recommended for troubleshooting. If you leave it jumped the car can start while in gear and lunge forward or reverse if left in gear. "Use caution"

2. Swap the Starter Relay in the IPDM E/R box with one of the other relays, it looks like the headlamp relays are the same.

Consider these suggestions and see what happens.

 

BTW, how many miles on the car? Has the starter ever been replaced?

 

Thanks for the fantastic detailed response. I'll dig into some of that (what's not too far over my head anyway) this weekend.

There are ~77k miles on the car. The starter has not been replaced to my knowledge. There has been no hesitation to start or grinding noises that I've historically known to be associated with faulty starters.