NewZed

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Not sure what The Avalanche refers to, thought it might be the Suburban, but I had a VG30E that had a Check light that would come on and go off randomly. Turned out the EGR passage was clogged with carbon. Lots of short trips over the years. There's a code for EGR malfunction. Count the flashing lights.

You must have left some pictures out. All that shows is an old beat-up 240Z with flat tires. There's another sub-forum for Member's Projects - http://forums.hybridz.org/forum/44-members-projects/ Doesn't matter much, but it fits.

Hard to keep up with this field. They're doing metal now. Who knows about durability in an under-hood application. https://www.solidconcepts.com/technologies/direct-metal-laser-sintering-dmls/ https://www.solidconcepts.com/technologies/selective-laser-sintering-sls/ https://www.solidconcepts.com/

How about rings of proper diameter from another engine brand or design? Rings, not pistons. There's been stuff written about using Honda XL500 motorcycle pistons. Might need to recut the ring grooves in the Datsun pistons but the rings might work. They must have worked for the guys using the complete piston sets. Here's one old thread from zcar that I found. http://www.zcar.com/forum/10-70-83-tech-discussion-forum/45301-honda-xl500-pistons.html Tony D mentions GM Vega engines in the post, another ring possibility. And a parts picture - http://www.japbikespares.com/honda-xl500-oversize-piston-kit-rings-pin-clips-89-5mm

Seems like prep work on the axles, similar to what people do on high performance connecting rods, might help. Removed all stress risers, massage the surfaces to distribute the load. Make sure the companion flange is engaged to the best depth to direct and distribute the load. Examination of where the stock axle broke might give some clues about how and why it broke. Could be that the adapter flange caused a problem. The same thing could happen with a bigger shaft. It's the fine details that make the difference when you're at the limits of the design.

When does the timing retard? Not really clear what you're describing. And there aren't really any design elements needed to connect directly to intake manifold. Once you open the throttle on ported manifold vacuum, it's connected directly anyway. Connecting to full time vacuum just gives high advance at idle. Ported vacuum gives retarded, more stable, idle timing

You can't tell much from external appearance. I had a fine-looking engine (they all look the same really) that was high miles, worn valve guides and old seals, only ran well after I beat on it. If you can't drive it or hear it run, you're at the same level of knowledge as a wrecking yard engine, except that most wrecking yards have a replacement guarantee.

If you're "rebuilding" to specs. for a turbo engine and you're buying new pistons anyway then all you really need is a good block and head to start with. $200 for a basic 280ZX NNA engine isn't bad, if it's in decent shape. Beats the typical wrecking yard price. L28ET engines are hard to come by.

The P79 and P90 have the same combustion chamber volume. Swapping heads will only get rid of the exhaust port liners. Read more stuff, especially the FAQ's on the L6 engine.

You can't see the springs and they're replaceable. Cutting a coil or two is common and shouldn't be considered butchering. If you don't have cash to burn on your hobby like some people do, cutting a coil is a simple, inexpensive way to get the job done. Now if you're planning to roll or cut the fenders so that you can drive it slammed, that might be considered butchery, if done wrong.

Part of your problem is the small diameter of your tires. If you're planning a tire change in the future you might factor that in also. Don't forget that distance of the body from the ground is more important for driveablity than tire-fender gap. Measure and focus on that. You might end up with a nice-looking gap, but be stuck to flat roads and off-street parking only. I used a bench grinder to cut my springs (all I had at the time). A simple cut-off blade on a chop saw, or hand tool will work also. The "don't use heat" advice is about using a torch to heat up the coil and letting it sag in to place. The camber problem isn't really there with the MacPherson strut system.

Why would you be targeting a number on a boost gauge? You can get that by adding restrictions. Here's a good primer on high HP turbo builds - http://forums.hybridz.org/topic/50208-the-ultimate-l28et-guidewhat-you-need-for-350whp/

So fatigue could be a factor. Upgrade options look expensive. Even the 39 spline needs a new adapter, adding even more cost. TTT has some alternatives for a new hub, that you could probably piece in, if you didn't want the whole kit. http://www.chequeredflagracing.net/Datsun.html https://technotoytuning.com/nissan/240z/complete-r200-r230-rear-end-conversion-z-car

Do you know yet what axles you were using? 35 year old stock Nissan axles, with MM CV adapters, or newer MM axles? Just curious. Seems like it could be a consideration.

It might be flow rate, but it doesn't seem like a pump problem. That pump is rated to ~90 psi and 30 gph. Have you checked for restrictions between the pump and the rails? Fittings, tubing, filters, etc. Clogged filter, funky brass fitting, teflon tape chunk. something like that. You might have 90 psi before the fuel filter, but 25 psi after, for example. In other words, the pump is fine, it's just working too hard to overcome restrictions. A simple check is to disconnect the line before the rails, after the filter(s), and measure flow rate.

The Hybridz search engine is worthless. Use Google. Type in the words "site:hybridz.org" before your search terms if you want to stick to the Hybridz forum. FricFrac. Find a spot where the car can sit for a long time while you install the new parts.

One of the first thing many people would do with a problem like yours is to measure fuel pressure while the problem is happening. Since it won't even start now, and you've already spent your extra money on a new pump, a can of starting fluid might tell you something. If it starts, fuel supply problem, if it doesn't, spark problem. Pull a spark plug and see if it's dirty.

"Lesser" is in the definition of the word "demote". Point of grammar. The OP was right. He got put in to a lesser group.

https://www.facebook.com/hokeperformance

Extra resistance on the coolant temperature circuit to the ECU would probably "fix" it. A potentiometer allows tuneability. I have two "lean" AFM's in the garage. The use of a potentiometer is described around the internet. Here's a good link, bottom of the first post - http://forums.hybridz.org/topic/95316-braaps-l6-efi-induction-advice-and-tips/

LSD clutch chattering doesn't fit the description. But good luck with it.

Another - http://www.carpartsmanual.com/datsuns30/DatsunZIndex/PowerTrain/TransmissionGears/tabid/1706/Default.aspx

What do you think is happening when you pinch the return line? Use some logic.

There used to be a kit available from Modern Motorsports but the company no longer exists. The AZC mount has issues? It was an interesting design, what's the problem? Seems like it should be modifiable.