New Owner 1993 Z32 TT Technical questions....please advise..

[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

This will help with ECU codes

http://www.nicoclub.com/archives/nissan ... ostic.html

[RobbieDobbie29]

Ok. I installed a new clutch, and it still slips. Just not as bad as the old one. Funny thing is, the old friction disc didn't look all that bad. Maybe the pressure plate was shot. I will run the ECU test tonight after my shift at work and see what I come up with. I will keep you all informed. I appreciate the help thus far.

Rob

[nissanfreak12]

The only other thing that could cause it to have issues is the slave, master , and lines. Make sure all the lines are bled out, including the one by the passenger fender/shock tower in the engine bay. I know you said you adjusted the pedal, are you sure its still not pressed in? You should have just a little play from the resting point till when you feel pressure. I think a 1/4".

The speed-o-meter thing, this is normal with age and stuff. I would either look for a new cluster or go to twinturbo.net, look for the user Bernie, he fixes stuff like that. I am unsure how much he charges, but from the other people on the site, he does a great job. Same thing goes for the boost gauge part.

Get rid of the MBC, spend the the money on an electronic boost controller and get an aftermarket boost gauge, a lot more accurate. They are not that hard to install, just a line from a vac port to the gauge.

Let us know what you find on the ecu codes.

[RobbieDobbie29]

10-4

[RobbieDobbie29]

And yes there is about a 1/4 inch of play in the pedal before any resistance is felt. I also confirmed this by pressing it in with my hand.

[RobbieDobbie29]

ok, I know I said the plug was white......it was actually yellow.....and it has one coiled steel line going into it. It's on the drivers side just above the oil pan but below the turbine. Here's a pic of it from under the car. What is it?

[RobbieDobbie29]

[RobbieDobbie29]

[t.mcginley.jr]

It could be one of the factory boost solenoids, there are 2, one for each turbo. When you install a MBC or EBC, you no longer need these so it's possible the PO left them in and just bypassed them. However, the plug itself looks like the one on the oil pressure sender unit that threads into the oil filter tree. Does your oil pressure gauge work?

For the factory boost gauge, they don't last long at all (neither does the factory oil pressure sender). Most people just get rid of it for an aftermarket gauge.

As for the speedometer, its most like the cluster like everyone said, although it could be the speed sensor in the trans (but not likely). The circuit board on the back gets corrosion on it and/or the solder points break with age and things stop working.

The Walbro pump is good up to 550 rwhp according to Z1, but a stock TT pump will outperform it (good up to 700+ rwhp).

MBC isn't really a problem if you're running stock boost. If you are trying to run higher than stock boost, then it will be an issue because things like humidity and ambient temperature will have an effect which could cause detonation, etc.

As for your clutch problems, sorry can't help there I don't know anything about 5-speeds. It's something I really have to learn about some time, including how to drive one haha

[RobbieDobbie29]

Yea, the oil pressure gauge operates normally, and it appears the sending unit for the oil pressure is on the passenger side of the car near the filter correct? This is on the drivers side and there is a single steel line that runs into this mystery solenoid/sensor....the line appears to coil before the fitting going into the solenoid/sensor. The line is about the size of a brake line, and runs up past the turbo. It don't look like a oil feed line for the turbo and there are no vacuum line attachments to or from it. Is this a power steering pressure switch.......or......? I've been busting balls trying to find out what this is in fact for. My Nissan ASIST program at work has the factory service manual for 1994-1996 Z Cars....but I can't locate this sensor as of yet.

[nissanfreak12]

JDM engines had the sensor on the driver side, so the RHD steering shaft won't hit it. I have the same thing on my JDM engine, same location. Are you sure the engine isn't from a JDM? It is possible it could be, its real easy to relocate to the passenger side.

[RobbieDobbie29]

It is a JDM engine according to the PO..... 45k on the ticker. Any differences between the USDM engine and the JDM one? So......the oil pressure gauge works........do I need to do anything about this one?

[RobbieDobbie29]

I was making my brain bleed trying to figure out wtf that sensor was for.....lol. Thanks freak.

[nissanfreak12]

And yes there is about a 1/4 inch of play in the pedal before any resistance is felt. I also confirmed this by pressing it in with my hand.

Here is a question, how it the pivot ball for the clutch fork in the transmission? Was there a lot of play it in? If that was good, I would not stress too much until after you get the master and slave cylinder.

Mr. McGinley- The clutch system is pretty basic, pedal press the master, which then pushes fluid to the slave, slave engages and pushes the fork which then moves on the pivot ball and pushes the throw out bearing onto the pressure plate then release from the friction disc. When you let go, the pressure plate sandwiches the friction disc to the flywheel. This then makes the the power go from the trans to the driveshaft. The friction disc rides on the transmission output shaft and spins with the trans. The flywheel spins with the engine.

[nissanfreak12]

It is a JDM engine according to the PO..... 45k on the ticker. Any differences between the USDM engine and the JDM one? So......the oil pressure gauge works........do I need to do anything about this one?

Nope, just cause its a PITA to get to. As long as it doesn't leak, just let it be. No differences between the engines except the Japanese didn't really take care of their cars, for the most part. Most of the time the JDM motors are beaten pretty bad, lack oil changes, coolant in the system, they tend to use just water. Plain water rust the hell out of the system. If the car has been running good, I wouldn't stress too much. Just keep taking care of it and hopefully nothing will come of it.

[RobbieDobbie29]

Pivot ball was in good shape. I used Nissan moly on it when I put everything back together. I am really at a loss for whats causing it to slip, other then the fact that the entire hydraulic system was filled with chocolate milk instead of clean, clear dot3 fluid....lol. I noticed little black specs in the fluid as well as "glitter" when I was flushing this gunk out....and then couldn't get a firm pedal for the life of me. I figured it was pieces of the M/C diaphragm and this is why I couldn't get pedal after the gunk was flushed out.


Water in the coolant system.......well that explains the Fukashima scenario.......

[RobbieDobbie29]

I honestly havn't been able to drive it yet due to the clutch situation. I very very gently drove it home and then to my job (Nissan dealer) and i have had it in the shop ever since.......waiting on o.e parts. I put a new clutch in it and it still slipped. Is it possible the booster is bad? i disconnected it and plugged the line and the clutch still slipped. I put the line back on the booster and the pedal went to the floor and stayed there.......

[t.mcginley.jr]

Mr. McGinley- The clutch system is pretty basic, pedal press the master, which then pushes fluid to the slave, slave engages and pushes the fork which then moves on the pivot ball and pushes the throw out bearing onto the pressure plate then release from the friction disc. When you let go, the pressure plate sandwiches the friction disc to the flywheel. This then makes the the power go from the trans to the driveshaft. The friction disc rides on the transmission output shaft and spins with the trans. The flywheel spins with the engine.

Thanks for the quick and dirty version!! Haha every once in a while I do some research on manual transmissions, I think if I actually had one to play with I would learn about it in no time. I deffinitely wouldn't want to learn on a 300zx though I would get some beater Honda

Water in the coolant system.......well that explains the Fukashima scenario.......

LOL

As for your question: yes the booster can go bad, just like the brake booster. The diaphragm deteriorates over time causing weird issues like the pedal going to the floor. It sounds like there isn't much you haven't replace yet, so it can't hurt to replace it I suppose. Plus you probably get a sick discount working for Nissan

[nissanfreak12]

If the pedal goes to the floor and stays there, either it has a ton of air in the system or the master cylinder is toast. Yes, boosters can go bad as stated, but more or less all the booster does is assist in pressing the the said parts. Think of it as having one leg that can press 500 lbs of weight with ease and one that can only do say 100 lbs. The 500 lbs is the one with the booster and the 100 lb one is without. Kind of a crude way of saying it, but hopefully you get the idea. If the booster goes out, it just makes the pedal tougher to push, just like taking the vac line off the booster, same effect.

Water in the cooling system, yep goofed up that one. I meant to say only water, no antifreeze or additive.

Are you absolutely sure you got all the air out of the system? Did you bleed both points? In the correct order?

[t.mcginley.jr]

Nah I knew what you meant, I was LOLing because of the Fukashima part (because the Japanese only use water for coolant, not actual coolant)

There has to be air in the system, or getting into the system, for it to still slip with all those new parts

[RobbieDobbie29]

I installed a new oe nissan master and nissan slave today after work. I filled with dot 3 nissan brake fluid. I bled the top first. Then the slave second......... Using a line and a bottle of fresh fluid to catch the air/fluid from the bleeders......still had a squisy feel for the top 20% of pedal travel. Jacked the front end up about 15-20 inches pumped the pedal and cracked the top bleeder for the hell of it. PPPSSSSHHHBBBFFFFF.....Burst of air and fluid.....one more time....all fluid. Now the pedal has a 1/16th inch free play..then all clutch after that. Check the slave push-rod when the clutch pedal is released to see if the fork is fully engaged......it's Money. Back it off the lift...on the test drive I go. First gear.....ooohhh yea feels good. Turbo's a spoolin'.....second gear....turbos come on nice.....oh jeez....the snowmobile clutch kicks in again! BBRRRAAAAAAAAAAAAAAAHHHHHHHHHHPPPP!!!!! But....no acceleration.

My Brain Hurts.

Possible that the flywheel is too thin????

[nissanfreak12]

How high from the floor until the clutch actually engages? How much do you have to press the clutch until the clutch actually disengages?

Are you sure you didn't install a NA clutch? Im sure they don't line up, but just checking everything now.

Did you resurface the flywheel? Chances are that the flywheel is ok. How is the linkage on the clutch pedal? Take special notice on the pin that connects to the adjuster, did you notice any grooves? Try adjusting it so its looser. See if that does anything.

[nissanfreak12]

Nah I knew what you meant, I was LOLing because of the Fukashima part (because the Japanese only use water for coolant, not actual coolant)

There has to be air in the system, or getting into the system, for it to still slip with all those new parts

That took me a minute to get it, when it finally hit, I chuckled a little, lol. Somedays, I am a little slow.

[RobbieDobbie29]

But the slave push rod has zero pressure on it when the clutch pedal is released. So the clutch appears to be clamping well. It's a Perfection Clutch brand clutch kit. $189.00 from Advance for the TT model.........laugh if ya want.....I know it aint the best.........I didn't pony up the dough cause I wasn't 100% sure the car was gonna run good due to the fact that when I bought it I couldn't test drive it due to the clutch slipping. It seems like its biting good....I'm just wondering if the flywheel is too thin or if i am having a friction disk/clamping issue due to a s*** quality clutch.

[nissanfreak12]

I just had a thought, do you know all the mods done to the car? It is possible you need to get a stronger clutch. Stock clutches only hold up to 350tq, and Im sure the one you have in there is inferior quality than OEM. This came to me cause the you had bite in first gear, but second it slipped. Its possible you have a beast on your hands or you need to quit buying cheap parts for the Z, I have found out they only like expensive quality parts. Very rarely do flywheels get so thin that it will not hold when you release the clutch.

You said the slave has zero pressure when the clutch is released, does the fork wiggle or is it o tight you cant budge it. With the clutch depressed, the fork should have some play, if it doesn't something is binding inside. How did the flywheel look before you put the clutch on? Did it have a glazed look?

[RobbieDobbie29]

Yea. The car seems fast. 2 into one downpipes front mount i/c, test pipes and stock rear section. Z1 hardpipe kit, manual boost controller set closed, hks ssqv bov's. thats all it has i believe.

[RobbieDobbie29]

The clutch fork is tight when the clutch pedal is up. I havn't checked it when the pedal is pushed down though. The clutch fork is supposed to be tight when there is no pressure applied by the slave cylinder right?

[RobbieDobbie29]

I think I'm going to pull the trans out at the shop again and see whats going on. It took me 2 hours in and out last time so it aint that bad. Maybe my fork is hanging up or something. I did notice one time that the fork didn't release all the way when i was under there bleeding the slave. I pulled on it and pop. It released all the way. Still slipped after that though.

[RobbieDobbie29]

This car is lucky I love it so much. What really chaps my a** is that I did a clutch on a diesel Dodge Ram 6 speed today......and that sucker didn't slip! Grrrrr.