To start with i have searched everywhere and nothing has helped thus far so im making this thread.

so to start with i just rebuilt the motor with forged internals, as well as installed the FM stage 2 clutch. I have the engine in, everything bolted down, ive fixed the few leaks ive had however this is without a doubt the biggest PITA thus far. As the title says it dies when i depress the clutch pedal, however a bit more specifically it appears to lean out and die. It doesnt matter if i only press it in a little bit or dump the clutch the rpms drop at the same speed. However if i go very, very, very slowly i can get the clutched depressed without it doing this. Ive gone through all my ground locations, all connections, all wiring harnesses that are related and i still have not been able to fix the issue. Hell ive even bypassed the both clutch switches as well as the nutral safty switch and yet it still happens. I called the lovely folks over at FM and they agree that if the throw out bearing is new as well as the crank only had 3 thou of play forwards or backwards, if i remeber correctly. i highly doubt its the crank causing this issue. Ive emailed a copy of the datalog as well as the tune file and i have yet to hear back from them. So i figured why not reach out and see if yall have any ideas because im 100% at a loss and i really wanna be able to drive my car for the first time in 3+ months. Also, how would yall recomend posting a copy of the tune and datalog file? Im on mobile and im not quite sure how. Thanks

ps im not sure if this data log was before or after i accidently disconnected the MAP line. It didnt have any impact on the issue though. Again thanks for any help.

 

I was initially going to say a thrust bearing problem. I can't think of anything else offhand but I can't view the log right now.

 

Disclaimer: This is a long shot.

• How sound is your firewall? Are you sure the firewall is not flexing when you depress the clutch pedal? A weak firewall will cause strange problems.
• Have you tried disconnecting and plugging the brake booster vacuum line to see if you can depress the clutch without killing the engine?
• What happens if you raise the idle a bit and hit the clutch? Does it still die? Does it still lean out?
• Does the car start (or try to start) with the clutch depressed?
• What is your idle vacuum?
• Are you absolutely certain nothing in your clutch assembly is installed backwards?
• Do you have a new pilot bearing?

Your answers will help to narrow things down.

Sorry but trying to diagnose a car problem sight unseen is damn near impossible.
Understandably, there will be some dumb questions to grasp the issue at hand.

 

I had this exact same issue like 10 years ago. I was doing a big wiring delete project with no real clue what I was doing. Unplug something that looked useless, crank car up, if car runs I'd cut the wires out. Like 5 hours later I was content with my progress, car fires up, touch the clutch and it dies exactly like you describe.

My issue ended up being a ground wire, this was on a 90 Miata. My 5 hour de-wiring project then turned into a most terrible weeks long re-wiring project. It's been so long ago now I couldn't swear to what the issue was, but I want to say the source was around the passenger side headlight area. Wish I could be more helpful. Definitely sounds like the same issue, assuming yours does turn out to be electrical.

 

Funny you should mention that.
At the risk of threadjacking, I had some pretty strange problems this past week. My windshield washer quit all of a sudden, among other things that were not up to par.
I removed both headlights, disassembled the multiple ground connections and cleaned them as best as I can before treating applying circuit cleaner/protector spray to avoid corrosion.
I went ahead and replaced the rusted bolts securing the connectors while I was there.
Not only that fixed my washer pump problem, I'm pretty sure my headlights are brighter now, and there's a definite improvement in "things" overall.
Car is 20 years old, so are all the ground connections...