New Z32 TT owner looking for some technical answers

[RobbieDobbie29]

Hey NICO forum members. I just recently aquired a 1993 300zx TT with a manual trans. It's a South Carolina car born and raised so, it is super clean. I bought it from the second owner.....who I feel didn't know much about the car at all. I say this because it has a few issues and he had no good (informative) answers for me. These are the issues I'm having to deal with.

-Clutch Slips when load is put on Engine. (He stated that he pushed the clutch in downshifting....heard a pop noise...and then the clutch slipped after that)

-z1 motorsports hard pipe kit. HKS SSQV bov's, HKS Turbo timer.

-Large front mount intercooler installed as well as two into one downpipes and test pipes. Megan i believe.
stock rear section.

-He says there is a walboro fuel pump installed. (I didn't confirm this yet.)

-Speedo doesn't work...odometer does......mph read-out on turbo timer functions but I don't think it's accurate.

-Manual boost controller installed on front of motor between charge pipes. Closed when I got it. Fitted on a 1/4" steel pipe running from the left bank to right bank. (he states that it is set at 9lbs when closed. I don't believe it)

-When you turn the key to on the factory boost gauge goes to +14 and stays there....even while engine is idling. It don't move until you turn the key off....then it drops to -14.

So, I ordered a OEM Nissan clutch kit and installed it after work last week.(I'm a tech at a Nissan dealer here in Savannah Georgia) according to nissan spec. While underneath the car I noticed a white electrical connector on the driver side up near the turbo that had no plug in it. Don't know what that is for. Didn't see a Pigtail present????? Backed the car off the lift and out for my testdrive I go. Got out of the garage and pushed the clutch in to put the car into second........the pedal sticks to the floor. So...i put it in neutral, shut the engine off and push it into the garage and up on the lift it goes. I pull the vac assist line off on the clutch m/c and i got the pedal back. Plugged the vac line and took it for a test ride. Clutch still slips under load, just not as bad as it did before. But it slips. I can't even come on to boost. Not good. So i check the clutch m/c fluid level and the fluid is chocolate milk colored.....so I flush the system and now I have no pedal. I bled the top line and bottom line at the slave using the appropriate method. No pedal. I pumped the system up and got clear fluid up top, tons of air at the bottom.....barely any fluid would push out though. even after 10+ attempts at pumping the pedal and cracking the bleeder screw.....I can't get any pressure at the bottom fitting. I noticed while vacuum bleeding the system little black specs in the fluid as well as tiny tiny metallic flakes. What the heck is wrong with this thing.....!!!? So i've ordered a O.E master and slave cylinder. It will be here Tuesday. In the mean time I set the clutch pedal to it's proper adjustment....the 2 switches were about a 1/4 inch past the welded nut....now there flush with the nut......and I backed out the pushrod to acheive proper pedal height.

-Any suggestions from you experienced z32 guys would be appreciated. My questions are....

-whats the missing/unplugged connector for? I have no CEL on and the car runs and idle's good although I can't really put a load on it. No noises or idle issues.

-Why doesn't my cluster speedo work, but the HKS T.Timer speedo and odometer does?

-Whats the deal with my +14 on the boost gauge while the car is key on engine off and while it's idleing as well?

-The manual boost controller? What should I do about it? I don't feel like it's safe and/or appropriate on a car of this caliber.

Basically, Any suggestions from you experienced Z guys would be great.

Thanks all!

Rob

[Exia]

Well remember these cars are using OBD1, so that check light is almost useless.. Run the ECU dtcs, and see what you get..

Second check your fuses and relays..

When in doubt reset the car to stock unplug all unnecessary crap for now ( Boost controller etc ) Could be possible he did a hack install job and spliced where he shouldn't..

Clutch issue, you need a new clutch or pressure plate would be my best guess

Fuel pump even Z1 recommends the stock TT pump, he probably did install a 255 because you can get them for 50 to 100 bucks..

Boost gauge is probably just sprung, get a aftermarket gauge or find a new cluster

[ThisIsSparTTa]

I don't have any extra suggestions, but I would suggest breaking your questions up into more manageable chunks. Right now reading through all that is a bit overwhelming. Maybe prioritize what you'd like to address first, and make a few different posts.

[Z-owned]

It is a mouthful to read and try and answer.

1. oem tt clutch isnt able to hold much power past stock so a upgraded clutch would have been a good idea. You never mentioned getting the old flywheel resurfaced or replacing it with a light weight one.? How did the friction disc look on the old clutch? Also your supposed to be gentle on a new clutch and allow it to break in, not doing so could ruin it and make it slip.

2. A pic of the white connector will help a lot

3. Did you pull codes and come up with 55? or just going off the lack of a cel on the cluster? I would pull the codes off the ecu to be sure.

4. the bov's and front mount probably aren't helping anything, bov's actually can negatively effect the car. There was a good article by Greg D. of specialty Z awhile back that explained it really well.

5. Speedo issue, is likely one of two things, A. the speed sensor is bad or B. the gauge itself is dead both of which are semi common issues.

6. I would get the vacuum diagram for the tt and check that everything is correct. The manual boost controller is something I would replace with a ebc sooner than later as well.

On a whole it sounds like you have a small project on your hands of fixing some sub par upgrade attempts. I would guess that the ecu was never upgraded and your on stock turbo's?