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After about 6 months of on and off again work and it's going again and back to making the Camaro and WRX look ugly in comparison.
New bearings, rings, turbos, injectors, ECU, exhaust camshafts, intake valves, gaskets, engine mounts, various hoses and clamps, and probably other stuff I can't remember now.
The Z had increasingly degraded performance for a while including slower spool up and lower peak boost. Then it started smoking. Nothing ruins the Z experience like having an embarrassing stinking cloud following you around in traffic.
Then a compression check showed the following:
1) 70, 2) 132, 3)125, 4)138, 5)148, 6)54 yikes a couple of lame cylinders. I then seriously considered moving on to something other than the Z32, but just couldn't do. So it was time to begin a major rebuild, the first I've ever done.I did all the work myself except I had a local cylinder head shop rebuild the heads, measure the bores and crank, hone the cylinders, and clean the block. The bottom end of the engine looked pretty good with the only problem that I saw was wear on the main bearing. None had failed or spun, but you could definitely tell that they were far from new. Before pics:
 After pics:
 It turns out that the compression problem was worn out intake valves. All the valves were damage, but about 1/2 the valves were dished out at the seats so bad that they actually had a sharp edge around the circumference. You could also tell the diameter of the valve was slightly reduced. The exhaust camshafts also both had a badly scored journal at the rear most location. I think the smoking problem was probably caused by worn out turbo(s) seals. I took this opportunity to upgrade while I had the engine out, including:
GT525 turbos
Nismo 740cc injectors (with adaptors for old style fuel rail)
Z1 ECU
BDE engine mounts
 Then came the after reassembly troubleshooting to get the thing actually running well.
• Had trouble getting oil pressure, see La-Z-Link
• Then I get it fired up, but only on 5 cylinders. Turned out to be a broken injector wire, my fault.
• Then it developed an unsteady idle and stalling when the clutch was depressed after cruising. I fixed at least four boost leaks. This was great and needed to be done, but didn't help my idle at all. Turns out somehow the base idle adjust got way off even though I didn't knowingly alter it during the rebuild. Anyway after getting all that taken care of the car has been running great. And amazingly (knock on wood) there are no leaks......of any kind. That's a first since I've owned it I think. It only has 250 or so miles on it so I'm still taking it pretty easy waiting for the engine to break in. I have high hopes for what it will do at 15 or 18 psi. We'll see. It's been my long time goal to have a 12 second street car and now, on paper at least, I do. I'll just have to go back to the track and prove it.
 . 90 300zx TT 13.285@106.08
94 Camaro Z28 13.751@101.83
03 WRX 13.973@94.88
02 Mazda MPV; four kids and a wife don't fit in the Z.
90 240sx (sold) 16.9@87 |
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Another Z brought back to life story (long w/pics) - 
