My 1990 300zx Twin Turbo build by megaDan

11 minute(s) of a 731 minute read

Finally installed the motor! My buddy pat came over this weekend from Chicago and we knocked everything out. A week after I posted my last message my Grandpa was in the hospital so the car was put on hold for a while.

After 2 full days of working on it this weekend, we got to try to start it without any accessories installed. AND IT FIRED UP!!!!!!!! It had a searching idle for about 20 seconds, and then died. No time to check codes or boost leak. We finished 15 minutes before we had to leave for girlfriends birthday dinner. 

BUT IT STARTED! Finally!!!!!!!!!!!!!!

3/15/2012

I had a few problems after the initial startup. During the first startup, I neglected to let the wideband warm up, so I didn't get any information from it. Also, I had a pretty bad oil leak (supposedly). And it died after about 15 seconds. 

I finished buttoning everything up monday night and tried to start it again, this time with nissan datascan. I learned a few things

A) My wideband is hooked up to the gage, but not to the wiring harness, and I cant find the connecter. I don't remember if it was ever plugged into the harness. I'm not really sure what to do about this one. The oem O2 on the drivers side works fine. 

B) I DID have a nasty oil leak. I forgot to tighten the drivers side turbo oil feed for some stupid reason. I was able to remove the AC condensor and the bracket with the motor in the car with minimal effort and tighten it down. No leaks this time. 

C) While I was playing around underneath the car I realized I didn't have my boost solenoid hooked up properly, the hard line going to the drivers side throttle body had a vacuum connection wide open which showed on my wideband as a very lean condition. Hopefully that's all I missed. My Z1 boost leak tester broke (THESE THINGS ARE SUPER FRAGILE, kind of pissed about this) so I have to wait until a replacement shows up.

D) The passenger side neck on my OEM radiator has a tiny leak, so I ordered new silicone coolant hoses and a Mishimoto radiator. I was having problems deciding which radiator to buy because I've never had temp problems before (other than too cold) with the OEM rad, but at some point I would like to drive out at Mid-Ohio so I should probably have adequate cooling. Next spring I'll be installing 2.5" intake piping, intercoolers, and TB's and I've heard installation can be a pain/impossible with a larger radiator. I guess I'll find out.

So for right now the car sits and I wait for my radiator before doing anything else.

Oh, almost forgot

E) I can't get the exhaust to line up for the life of me. When the test pipes are LOOSELY fixed to the downpipes, they sorta line up length-wise, but as soon as I bolt them down (in any order) they differ in length by almost .25". I'm totally stumped as to what to do. They fit fine before, but I understand that exhaust location is based on turbo type (sport 500's = OEm housings) and exhaust manifold placement (AMS). Is it possible the mounting of my AMS manis are misshapen and preventing my exhaust from lining up? Should I just bolt the test pipes to the H pipe and hope that holds it?

I've reduced the "damnit not again" problems from 3 down to just the exhaust problem. I'm still pretty optimistic.

3/20/2012

This thread needs an update!

Had some major problems with this car last fall. Rather major problems with the work that was done. Gonna copy and paste posts I made over at 3zc to get everyone up to speed with where I am now. Sadly, few pictures as of late. But I got my girlfriend a Pentax K-x for her birthday so you better believe when this is running there will be PLENTY of pics :-) 

Mishimoto radiator and new radiator lines get delivered tomorrow after work. The girlfriend will be out of town this weekend so I'll have all weekend to either button everything up, or take it for a test drive.

Sadly my registration is expired and its still on 'storage' insurace so I need to get both of those items taken care of at lunch today. 

I've got a Nistune ECU waiting to go in after I get the motor broken in. Some big name Z tuners are coming to Cincinatti in May and I hope to be able to take the car down there and get a top quality professional tune. I just hope I'm not getting ahead of myself again. 

3/20/2012

With all due respect to Dan, a Z32 300ZX is a car I'll never own and ownership I wouldn't wish on my worst enemy. My best friend is the biggest Nissan nut you'll ever run across, and worked as a tech at a Nissan dealership from 2000-2004 (the time these cars were getting out of warranty). A couple of the other tech's had Z32's and I often gave a helping hand working on them. I'd rather re-run vacuum hosing on a TT FD than do just about anything further than basic maintenence on a TT Z32. The TT Z32 is still the most pain in the ass vehicle I've ever worked on. If I remember correctly, the last Z32 I turned a wrench on was to replace a turbo, and it took 4x removing engine and installing engine to get all leaks stopped and everything fitting properly.

With that said, when they are put together, they are damn fun cars. I used to bracket race with Brad Grodi @ ZSolutions. I don't know if he's still in business but back in '07-'08, he was running 700-800whp and driving his Z everyday.

You know....I don't mind having to work on the car. Yes, it really sucks when a fuel line that runs UNDERNEATH the plenum AND throttle body linkage starts leaking like a firehose when you're 30 miles from home....but you sure learn a few things when trying to fix it. 

Pretty much the only 2 cars I've spent any real time working on are my 300zxTT and my Golf VR6. Everyone told me that the Golf would be a pain because it was a 6 cyl engine in a bay built for a 4 cyl. I don't see either as a pain to deal with.

I love both of my cars, and the work I have to do is the cost of owning the car. I love EVERYTHING about the 300zx. I love the exterior, how it feels to sit in the driver seat, how the rush of power feels when the turbos kick in (and that was stock power levels before...haha). 

The way I see it is if I ever need to work on an 'easy' car...I'll be set. I have learned more than I ever thought in the 3 years I've had the Z. Case in point, I wasn't into cars at all when I started college, but all my friends were complete gearheads, so I absorbed what I saw and heard. My best friend is/was a Nissan freak, and I helped him find his 300zx slicktop. After I got a ride in that car I was hooked. I bought my TT a few years later. He was the one helping me reinstall my new motor last weekend. After we got the motor in we realized that the water pipes that run under the lower plenum and between the heads wasn't bolted down completely (letting RTV cure) and it was sandwitched up against the firewall. We already had the motor and trans installed and in place. (sorry pat) He thought we were hosed and wasn't really sure what to do. I removed a heater core hose, grabbed a 3/8" U joint, a 1/4" wobble joint, 1/4" u joint and 1/4" extension and snaked the fittings onto the bolt head with my fingertips and managed to get all 4 bolts torqued down. 

Ask me to do that two years ago? No way would I have figured that out. I guess another way of looking at it is: if you have to do it every day, and don't know anything different....its not bad; its just normal. Plus, when you have all the bypasses and deletes done AND a top feed fuel system, most of the biggest PITA's no longer exist. 

3/22/2012

I found my 02 connector last night. But more about that later.

First of all....my new Mishimotor radiator, Z1 silicone coolant pipes, and replacement boost tester showed up from Coz last night!!! And I had to wait until 8pm to play with them. It was 85 degrees in Northeast Ohio....softball comes first.

When we got home I installed the radiator which I was afraid of based on all the horror stories I've heard about aftermarket radiator fitment. I left the intake hoses on the passenger side installed throughout, and it took all of 30 seconds to figure it out. I just had to put the driver side of the rad in first, lowering the radiator tab below the metal intercooler pipes. Once I was able to slide it over and down, the whole radiator moved into position. Nothing had to be removed or loosened. Hooray! I'll have to take a picture tonight, the radiator seems to sit pretty high, but the hood does close.

Once I lubed up the silicone hoses they slid right on. I had to trim the radiator side of the upper pipe about .25" to get it to fit, since this rad is so much thicker. 

After my rad install I attempted a boost leak check and couldn't build pressure even with the regulator set at 50psi or so on my compressor. Gah! Need to figure that out before I try to start it tonight.

Task number 3: Hook up heater core valve properly. This was a pain in the @$$$$$$$$$$$$$$$$$$$$$$$$ $! I had the heater core installed last fall when I did the bypass, but I never hooked up the spring and cable to the valve. It took me about 30 minutes lying on my back under the pedals to get this thing hooked up. I had to pull the valve back off the heater core, thread the cable through the valve handle, and spin and contort it to get the valve back on the heater core AND back into the rubber bypass hose. There should be pics of this earlier in the thread. Unfortunately I didn't have my phone on me to get any last night.

Last task: Missing 02 sensor plug. For some reason I felt like I had both 02 sensor plugs in the harness despite using a wideband 02 in place of the PS 02 sensor. I had to backtrack my bees nest of wiring behind my 300 degree triple gauge pod and below the radio. I traced all the wires coming out of the firewall from the LC-1 unit, followed all the leads until I found the one that didn't go to the gage or ground/power and found it running back to the firewall. However I couldn't find that wire in the engine bay side. Turns out I spliced it within a few inches of hte firewall grommet. I found the wire spliced to my old 02 sensor connector, which somehow got stuck on top of the turbo. It was COMPLETELY hidden from view. I snaked it out and plugged it into the wiring harness.

At the start of the night I was bummed again because I thougth I had a few problems that were going to take a lot of work and delay this project even more.

Tonight I need to keep hunting down my boost leak (no hints last night, no whistling or anything) and then I can fill up the rad and start it up and hopefully let it idle for 20 minutes to FINALLY break this motor in.

Neighbors may not like me as I have no exhaust. :-)