Recently replaced my motor. Been driving the z for two days and she's been a beauty. Today, I was driving home and in first gear and right as I hit 5k my RPMs started jumping like crazy so I let go of the gas. Took off again and it kept doing it. I've never experienced this problem till now. What could it be? Clutch going out? ECU in limp mode? Also as I'm driving as I'm shifting my gears start grinding all throughout. I have to let the clutch pressed I. As I put it in neutral then back into the next gear and everything goes smoothly. Any input would be great. Thank you guys

 

Who installed the new engine?

 

Me and my mechanic friend. He works for dealerships. And this is my second swap I've done. Any insiders tho. Don't hold back, y'all won't hurt my feelings.

 

Do you mean when you were in 5th gear and you stepped on the throttle, the revs went up the car's speed didn't? If yes, that's a slipping clutch, and it may or may not do it in lower gears, but it will eventually if you don't fix it.

 

It jumps with all the gears and it sounds like it's grinding on all gears too. I had someone tell me the pilot bearing. Since I took an automatic engine and put it into my manual transmission. Is this correct?

 

if you're saying there's no pilot bushing, then yes, that's one problem, and you need to install one. Would a missing pilot bushing cause your symptoms? I don't know.

 

I have a video on what it does. I just ordered a pilot bushing from z1 so I'll just wait for it.

 

Sounds like a failing master/slave cylinder, which may or may not have lead to a failing clutch.

If you are running the car with no pilot bushing, your input shaft is basically completely unsupported on one end.

Keep in mind auto and manual 350zs have different pilot bushings. To do what you are doing you need an adapter if memory serves.

 

I'll check everything once I get the new pilot bearing. What would cause my RPMs to jump all crazy tho?

 

Clutch slipping would only do that.

Did the tranny mate fine to the engine?

As for the grinding it sounds like the clutch isn't disengaging completely

 

Did you replace the clutch when doing the engine? New parts wear out older parts quickly.

 

I did not replace the clutch. The clutch is a year old. And yes, the transmission bolted onto the engine just fine. It worked great for two days before it started doing this. I went to work and after I get off it started doing. So I was a little lost on why.