Ineptitude01

Okay, I had my most boring class today, so instead of paying attention, I revisited my compressor map. Turns out, I did a few things wrong. Today, I followed to the letter the guide on this site: http://www.lovehorsepower.com/MR2_Docs/compressor_flow_maps.htm This matched up with what I've learned from Maximum Boost, and more google searches. I tried again with a volumetric efficiency of 85%, which is what was suggested for a stock 2 valve engine. It still seems a little bit optimistic to me for the L28, but maybe with a reconditioned P90 head, the ol' L6 thinks about it. In any case, I screwed up the 20% redline flow bit, since I had failed to understand that it's supposed to be at a pressure ratio of 1.0, which makes a lot more sense. So I redid the map, and the whole thing looks much closer to what I've been observing actually driving the car. I always like to have an explanation that fits my symptoms. So here's the map done over again for 7, 10, 12, 14, and 16psi. The knee on each PSI rating is at 3500rpm. If it were at 4000rpm instead, the knee on 16psi would be right on the surge line (24.61lb/min). Clearly any more boost than 16psi would do a whole lot of nothing, even were it inside the surge line. The more I drive this turbo, the more I like it, but I'm having trouble fully enjoying the thing right now. I'm having significant trouble with my ECU connectors at the moment. The slightest wiggle on the connectors can kill the motor, or cause it to have a rich, lopey idle that turns into an inability to rev over 2000rpm. The poor car is dying mid intersection, coming back to life, flying to 3000rpm, dying, and then idling at 650 thereafter. Wiggling and swearing can get it to have a proper idle with no richness, but for the moment, it's a pretty unreliable mechanism. I'm going to go out and get some Caig DeOxit tonight, and see if I can get the pins cleaner, but I'm not optimistic. When my spring break comes up, week after next, I'm planning on installing a compressor bypass valve, doing the 300ZX ECU/MAF swap, and converting the popoff valve to a pipe plug. I'll keep this thread updated until I have a final report on this turbo application. Lemme know if the new map makes more sense.

This past weekend I installed an eBay MBC and raised the boost to 10psi. Still seeing no problems. It runs better than ever, actually. I haven't seen (or heardany surge. The other thing I'm now considering is that when I was calculating the numbers for my map, I assumed a very low volumetric efficiency for the L6. I'm pretty sure that I used 80%, since I have pretty low expectations of the L28ET's flow potential. Now that the shock of first startup has worn off, I'm discovering that I'm really hitting full boost more between 3200 and 3700 than by 3000. This is obviously 10psi now, but I feel like it was the same story with 7. What should I have assumed for the volumetric efficiency? 85%? Certainly not 90%, right? Maybe I'll just build my spare shortblock out as a forged piston stroker. Rebello's not that far from me, after all. Displacement seems like it would fix my problem.

Definitely it can. Trying to fix this problem, I noticed a few other things I would never have seen - loose hose clamps, etc. Sometimes, though, I just want my car to start.

Ooh, ooh, ooh! This happened to me also. Right after I had taken the ECU out to inspect it. The fact that you got it to fire up after you put the ECU back pretty much confirms what I was thinking. My car was dying randomly, refusing to start, running badly... I replaced the dizzy, AFM, TPS, everything related to the system. Turns out that the wiring on the ECU is kind of lame, in that even when it's pretty clean (5 rounds of foaming contact cleaner) it still comes down to a few millimeters of wiggling that will just kill it. If you haven't done so already, I recommend taking the ECU connectors out, and getting some DeOxit (or similar) on there, then getting a file and veeeerrrrry lightly scraping at the pins to break loose corrosion and gunk. It made a world of difference to both my Turbo and my dad's Turbo.

Try shorting your starter with a screwdriver, just to verify that everything isn't ruined forever. It sounds like you've got a problem with the wiring to the starter solenoid, or the solenoid itself. My dad's car did this for a while, and it ended up being that the actual ignition switch was screwed up. He changed it out and it's worked perfectly since.

This happened to me also. The head and exhaust manifold go through many many many heating and cooling cycles for a number of years, and after a long time, they have the same slight variances. Different engines will heat and cool differently, and from that, they'll have different variances. I had a broken stud on the turbo manifold that came with the engine, so I used one from an 81 L28ET with a thrown rod. The 81 manifold was ever so slightly different than the original one had been, so I had the same problem. It just took one long night of wiggling and dead blow hammering to get it to go on right. And after all was said and done, it wouldn't fit with the intake manifold, because it was just slightly different in shape. I had to take it all back off, and use a dremel on the edges of it (NOT THE SEALING SURFACE) to get it to hook up right. Hope this helps.

Ahoy, naysayers! I return with news of first startup and delicious turbo spool. The T04B is doing great for me. Still running stock boost for break in, but I've got my homebrew MBC waiting in the wings. Comparing it to my dad's 83 Turbo with the stock T3... there is no comparison. I hit full boost at 3000RPM instead of 2800RPM, but my spool starts earlier, and I have far more lowend. It definitely doesn't have the sudden onset of boost that you expect... But I promise, I'm still getting the whole 'OH GOD I'M FLYING' sensation coming through first gear, and I hit full boost in first, which I haven't seen on the stock 83 yet. No surge so far. Still at 7psi, but maybe we'll see some more coming up on 12. I'll definitely keep you guys posted, but right now, I'm real pleased. It's very drivable, and the helical LSD is maybe my favorite thing ever. I wish I knew a place in the Bay Area that would let me do dyno runs 'for science'. I'd love to see how my power curve compares to stock. Just using my gut feeling, stock feels exponential, and my turbo feels logarithmic. And I'm loving this potential convexity.

FINAL UPDATE; PROBLEM SOLVED Okay, I got some egg on my face, and I feel real dumb, but if I don't post this, nobody learns anything but me. So on the off chance that this helps someone, this is my contribution to HybridZ today. I really do wish more people would come back after they fix their problem, and tell all about what it was, and exactly how they fixed it. I find myself over and over searching for solutions to problems, and finding that people have had them, and then never reported back. I get it, I get that HybridZ is all about 'search', don't ask, and I try really hard to do that. Still, I think it gets to the point where I have questions that might be helpful to everyone, but I'm afraid of getting shot down, so I don't ask them. I search, find my best guess, and work it all out for myself. We, as a community, have to make sure that we share the knowledge we have, instead of just waiting with fingers on triggers, looking for potential spooners. [/soapbox] Anyways, I didn't tighten the cam sprocket down well enough when the engine was still on the stand. The first peak vac pull downhill loosened it far enough that it came off the cam nose, but not all the way off. so it made no weird noises, and behaved normally enough trying to crank. I finally noticed it when I had the valve cover off. Mechanical timing was still perfect, bright link where it should be. I put it back together, and it started within 5 seconds. Ran real rough, wouldn't rev over 3500rpm. I had the bright idea of cleaning my ECU connectors and wiggling them around. Stable idle, smooth power all the way up. Runs great now, despite T04B naysayers. Shoutout to Roger, who helped a lot, and supported me in all this. Good idea after good idea. And HybridZ... I still love you, but dammit, I'm mad at you right now.

Whoops, sorry, I missed your post! I checked compression with my dad's tester, but it's kind of a piece. Looks like ~90 on all of them, which is what I've read as being right for un-set rings. As far as the hoses go, I've replaced EVERYTHING. Not one original hose is left on the manifold. The only ones are around the AFM. The AFM on my dad's car went out, and it was also causing weird problems. Is it possible that the same thing has happened to me here? is there an easy way to check the operation of the AFM?

Ah, I was saying that I have it the factory way. It doesn't go straight to the starter, it goes to the body, then to the starter. all I did was replace the too-short battery to body cable. I kept the place where it grounds there, because I figured (correctly, you say) that was important. I have a 79 parts car that I can take the FPR from, also. I'm having the weird problem of having bought a car that was barely running. Now that I've rebuilt the enging, I have no idea what else was actually broken. The huge clouds of smoke coming out from the turbo were the bigger concern when I got it, so things like the battery, alternator, plugs... I had no idea if they were good or not. I've just replaced them all out of habit. It didn't smell like it was running rich before the rebuild, but then again, it barely ran. I see what you're talking about with making the fuel pressure gauge. I'll give that a shot this weekend, shouldn't be too difficult. I'm going to get some battery cleaner on all the battery connections, including the frame ground, just to make sure it's all good. Thanks again for all your help.

Rats. I thought I had done my homework before I sent the turbo off to the shop, but I guess I needed to do a little more. Well, I was going to keep boost stock until break in's over anyways, so I guess I'll just have to see how I like it. Is there any chance that having a 0.70 A/R is going to make it play a little nicer with the L28, or am I totally screwed? I mean, this compressor is ENORMOUS, compared to stock. I have a hard time believing that I'll ever see 12psi at 3500rpm. 7psi I can believe, since the stocker tends to be in the 2800 range, but it just seems crazy that it would be able to spool up so quick, for being such a big ol' thing. Just found my pics of it on the bench. The shop did a really good job with this thing, I just wish I'd given them a little less creative license. They maintained to the end that this thing would be able to do 18psi for me some day, if I really needed that. I'm starting to think not. Anyways, pics:

Oh jeez, of course the engine was turning over, duh. I don't know why I said that. The positive looks fine, but the negative was just too short. It looked like someone had cut the old cable by a few inches and installed a new clamp. I unbolted the frame ground (was real close to the battery - just below it) and took off the battery-frame ground piece, and replaced it with a longer, nicer cable. Prior to that, the battery had been able to wiggle around enough to kill the circuit, and after I installed that longer cable was the last time I successfully started the car. So it's like it was from the factory, negative to frame to starter. I'm not sure if I have a spare FPR I can try, but I can scrounge around. I need to read up on checking fuel pressure, also, since that's something I've never done before. Is there anything I could have done hooking up the engine again that would have raised my fuel pressure? Seems like it's just the FPR that would have a say in things there. Frankly, though, the more I think about this, the dumber it seems, and the more likely I think it is that I've missed something really obvious. Maybe I should try going through the whole EFI Bible troubleshooting checklist, if I can't figure this out after all's said and done.

I haven't checked the fuel pressure with a gauge. I did the more lowbrow "If I disconnect this hose, and turn the key to 'ON', does fuel spray everywhere?" test. I did lay the plugs out and verify that they were all sparking. Now that you mention it, though I was having trouble with the battery. It didn't seem like the alternator was working at all, which could very well be the case. I didn't drive this car more than 10 feet after I bought it, so I have no idea if the alt worked. I switched out the negative battery cable, also, because the cable that was on the car was too short to reasonably reach a battery. Now I've got a much beefier cable on there that can certainly reach, and I cleaned the contact surfaces before installing it. I bought a new alternator the other day, and I'm going to install that this coming weekend also. Even if that wasn't the problem, the alternator that's in there now looks to be nice and old, and full of grime. So my to do list as it stands is: - Disconnect fuel pump and "start" car with wide open throttle until there can't be fuel in the manifold - Replace alternator with new one - Check starter for proper operation, verify that engine is turning over (it sounded like it was, and I can't imagine getting spark without that) Maybe after a week of sitting, it'll just work for me.

Sorry to bring this back from the dead. Been busy with first startup. I just drew up a compressor map, can someone verify that it looks okay? My math is according to the Atlantic Z turbo page, and I think this should be right. Looks like I really did need a different compressor. Since the money is spent, and it's on the engine, what should I do? Tear it off and start over? Is there any chance that I'll somehow have a slow enough spool to be safe? Maybe I should just get an intercooler with huge pressure drop...

That is pretty bad. Although, you see '1983 280Z' all the time on craigslist. Thing that offended me most was when someone was convinced the roadster came with a V6. Amateurs!

Look up Dr. Injector on eBay. Got a full reman and tested set for $189, work great.

Never heard of them. Typically you don't want to cam a turbo motor, as far as I know. Did they shim the cam towers when they shaved the head? What are the specs on the pistons? Is the pin depth the same? Are they dished? Forged, I assume. What's the approximate compression ratio?

Guys, guys... Working on cars doesn't HAVE to be expensive. You can cut your springs, spray your hood flat black with paint you found in the shed, go junkyarding for some HIDs and turbo emblems and just pocket 'em... Hell, I bet passwordJDM will just mail you some stickers, if you ask. But working on cars RIGHT can be expensive. If you plan to take the engine out of the car, do it right, or don't do it. You can get it in and out moderately easily from the top with a cherry picker. If you have a way to move the engine once it's on the ground, you can drop it instead, but a cherry picker is still going to be the method of choice. Craigslist is the way to go. Get 'em used. Good paint doesn't makI bought my hoist for little more than $100 or $150, I don't remember which. My engine stand was about $50. Investing in useful tools is NEVER a waste of time or money. I was convinced that I had finally found the waste of money in buying ratcheting wrenches, but they've ended up being far and away my favorite tool. God, and what happens if you drop the crank, and it doesn't hit you, it hits the concrete? Then you don't have to wonder whether it needs to be worked on, I guess...

I guess the thing that really threw me is that it was running great, up until I tried to drive somewhere. I hadn't changed anything, and it just stopped working. I still like the theory, since it explains my symptoms, but... What in those conditions could cause this to happen at all? I haven't adjusted my TPS yet, but I don't think that would cause it... Right? I did get the engine pre-oiled by pulling the plugs and cranking for a while, but after I got it to fire, I ran it in neutral at 2000rpm for 25 minutes. Could there still have been fuel sitting in the manifold at that point?

That's a good point, I hadn't thought of that. I'll definitely try that this coming weekend. I feel like I did try cranking with WOT, and I seem to remember it backfired into the intake, or from the exhaust. It was very very loud. Worth noting also that my alternator didn't seem to be working. Either it was bad when I got the car (barely ran, so I have no idea) or maybe just that I got it nice and wet filling the radiator on first start (pretty sure I did. Spilled lots of water into the fan - you know how it is. ). The oil pump and dizzy thing was what killed me the first time. First I didn't prime the pump. Then I was 180Ëš off. Now it's perfect, since I actually overcame laziness and removed the valve cover like a good boy. I had it at exactly 23ËšBTDC, and I'm pretty sure that's no problem anymore. Be that as it may, I AM using an aftermarket coil, so I'm a little worried about the spark. It's a FlameThrower, if that's something I should avoid in the future. I loved the one I had on my 82 NA, so I dunno what to think. What would have caused me to flood the manifold like this? The injectors are brand new, the O2 sensor is brand new, etc. I've never heard of this happening before, but now that you bring it up, it seems like that's what the problem must be. And I'm going to be disconnecting the electrical in the rear, at the pump, right? and just whatever fuel is in the lines does whatever? I guess without pressure, it won't do much... Is it possible my FPR is toast? Time for a pallnet and a RRFPR?

Okay, further update. The first set of plugs was fouled by oil, no question. The second set was fouled by FUEL. I took them inside and got a better look (and smell). The car still won't start. I used a compressed air hose to blast out the cylinders, and correctly so. There was a lot of unburnt fuel in the cylinders. Did a basic compression check with a crappy tester, saw about 95psi on all cylinders, which is what I would expect for unset rings. So I have compression, fuel, and spark. Maybe my AFM is welded shut? I guess we'll have to find out the hard way... Still hoping for a simple solution. Can't touch the car again until next weekend, though, so this is going to be a long and frustrating week.

Update! The new plugs are ALSO wet with oil! Have I destroyed my rings already somehow? Or maybe my stem seals are leaking? I pulled one of the plugs, B-12'd it, and grounded it while cranking. Nice spark, once the oil was off of the electrode. Any help is good help! Thanks.

I'm pretty much stumped. I did first startup yesterday on my freshly rebuilt engine, and it ran great. Got it up to temperature, did a little shakedown, looked for leaks, etc. Everything sounded fine. I had it running just fine for 25 minutes or so, keeping it between 1500 and 2000rpm as I've been told to. I tried to take it for a first drive, but it stalled. Going downhill. In gear. When I try to start it now, instead of making the normal 'starting noise' (RRrr, RRrr, RRrr), I'm getting a constant whine, and it seems like the engine is spinning faster than usual, but I'm really not sure. Every ZX I've ever worked on had a different 'starting noise'. I am getting spark based on what I can see with a timing light. The plugs were fouled a bit, but I replaced them with a known good set. I've got good fuel pressure, so I'm stumped. The distributor is brand new, I just cleaned every EFI electrical connection including all the injector plugs. Injectors are also brand new. Fuel filter, ignition coil, plugs, everything is new. If I entertain this weird whining noise, I get a giant blasting noise out the tailpipe after about 15 seconds of trying. Has anyone ever had this problem before? I'm just worried that I've wrecked the rings somehow, and now have to start all over. The only compression tester I have sucks, and I wouldn't expect to see normal compression numbers before the rings set anyways.

79s tend to be lighter, if you care. I like the chrome trim better, but keep in mind the 82-83 has far better rear suspension. The ideal is to end up with rack and pinion power steering, 82-83 rear suspension, an R200, and CV axles if you can swing it. As far as what car, do whatever's easiest, with respect to that criteria. A chassis is just a part, until you factor in the DMV.

What do the turbo ones look like?