NewZed

I think that y'all are describing the effect of high CR, but not the influence of the ECU and AFM. He's just asking for the reasons the stock ECU and AFM won't work with higher compression ratios, which might not be a valid statement anyway. Might be mixing two issues, better flow and higher CR. My reading is that the ECU and AFM are generally thought to not work with improved breathing or flow modifications, not necessarily high CR. And nothing will really support the advantages of higher CR, it's just an inherent limitation of the L engine cylinder head design. But it seems that, in theory, since the AFM and ECU are supposed to maintain a certain air-fuel ratio, that they should work in the low air flow range, at least up to the limits of maximum fuel enrichment. So lower RPM, moderate driving, should work but you run out of fuel at higher RPM (higher air flow). I haven't seen a real detailed explanation myself, of what happens and why, when you try to use the stock ECU and AFM on a modified engine.

Even the turbo cams are designed to produce decent performance when the engine is "off-boost". It's designed to work with a low compression ratio engine, but shouldn't necessarily cause lower cylinder pressure. So it would probably get you by, but would not work as well as one of the other stock cams. Plus, it's internally oiled, which needs to be considered. You didn't say what you're using that broke. And you left out the most interesting part - how did you break a camshaft in half?

Maybe I can learn something here - why would a mechanical pump stop pumping while "driving up the mountain" and why would an electric pump be different? Is the pump failing due to altitude or overheating or "vapor lock"? Just curious, what's your reasoning?

Missing link?

There's really not much else, with carbs. Strong spark at the right time, with fuel (assuming it was running well before). Recheck your timing and your firing order if you're sure that your spark is strong. Check your plugs, they may have fouled while you were trying to get things straightened out.

Here's some help on your second question - http://forums.hybridz.org/index.php/forum/93-megasquirt/

Have you confirmed that you're getting any spark at all? This is timing-independent, nothing to do with firing order, vacuum hoses or anything else, it will tell you if there the coil is charging and the module is working. Put a spark plug on the end of a plug wire from the cap, place the threaded portion on a good ground, crank the engine over and look for spark between the electrodes. That would be step #1. If you don't have that, then you can focus on figuring out what's wrong with the module or your wiring, before worrying about timing. If you do have it then you can worry about timing. One possibility - I have on occasion, forgot to put the rotor back on to the shaft before putting the cap back on, after changing distributors. No rotor, no spark.

I've not confirmed it but the FSM implies that some 1979 ZX models had the 3.36 R200 also. Edit - got curious and looked in the 74 FSM and the 3.36 seems to be the R180.

I slit a piece of hose lengthwise and stuck it over the peg. It's almost too much, the hatch takes a tug to get open but it tightened things up.

The problem might be in your ratchet extension shifting mechanism, it might not be rotating far enough to properly engage and/or disengage the ears on the shift rod. Take the handle out with it in neutral and try grabbing the coupling sleeve (the grooved ring that shift fork rides on) and shoving it on to the splined hub. It will take some effort because you won't have the leverage of the shift lever, but it should be comparable to the 4/5 shift. Or borrow a shift lever.

Here's the howlermonkey writeup in the middle of this thread, Post #17 - http://forums.hybridz.org/index.php/topic/70115-stock-l28et-turbo-return-lineflange/ Why not use the drain plug on the bottom of the pan as the port of entry for the returning oil? If you really don't want to take the pan off, or want something to get by until you can do it "right".

Your 76 280Z parts should all fit, once you remove the automatic spacer, if it's still there, from the L28ET engine. The backs of the two engines will look the same. Your 76 came stock with a 225 mm flywheel and clutch so should still be on there with your 4 speed. You could take the flywheel you have on your current engine and bolt it to the turbo engine. The 225 mm clutch is small for the turbo's power though, as I understand things, so you might consider a stronger aftermarket 225 mm clutch and pressure plate. Or you could resurface the 240 mm flywheel and get a 240 mm disc and pressure plate. Basically, it could be a plug-n-play, except for the strength of the stock NA clutch, which might end the playing sooner than hoped. Full disclosure - I've never had a turbo engine.

Worth a shot. Not to fill you with dread, but I had an ECU go bad and it died by dumping fuel through the injectors like they were stuck open. A couple of muffled pops, some gassy smoke/vapor, then flooded. It was a spare that I was testing and it ran fine for about a mile then stranded me. Put the old one back in and back to normal. 1976 280Z.

Saturated plugs is a good clue. Maybe it's fine except for the wet plugs. Dry the plugs, confirm good spark while one or two or all are out (will help dry the cylinders out also), and try again. Add details of what exactly happens when you turn the key to Start - noises, gas smell, popping, etc. "Doesn't start" doesn't really give much to work on. The welding might have had no effect at all. If you want to test a few things first, try the three taps to ground from the negative coil post trick to hear if the ECU is firing your injectors when it should. That will show if the coil is working and if the circuit from ignition to ECU to injectors is right.

With a carb you should be able to hot-wire it from under the hood. Power to the coil positive and a screwdriver on the starter posts. At least you'll get an idea of engine quality and can decide if fixing the wiring is worth it. Make sure it's in neutral before you jump the starter.

Heat would destroy any thread-locker that was present, plus give some expansion of the nut. I'm always surprised by the effect.

Maybe he was venting his disappointment. The title implies that there's more in the thread than just a question. The 1990 300ZX is the Z32 I believe, with the short nose R200. That is the more difficult diff swap. See here - http://forums.hybridz.org/index.php/topic/49194-differential-cv-lsd-hp-torque-r160-r180-r200-r230-diff-mount/ Buy here - http://www.modern-motorsports.com/catalog/product_info.php?products_id=74&PHPSESSID=664fa626f11aa37b79b99a9dd82712be

"packing bearings" on youtube - http://www.youtube.com/results?search_query=packing+bearings&oq=packing+bearings&aq=f&aqi=g3&aql=&gs_l=youtube.3..0l3.272.7550.0.7837.22.22.5.7.10.0.157.1066.6j4.10.0.

Sudden death is typical of loss of spark. Ignition module would be next in line after the other things you've tried. The AFM is just a potentiometer, no transistors to overheat.

Pretty sure the 75 ECU is the same as the 76. There should be part numbers on both. The ignition module could be your problem, they do tend to fail or show that they're failing when hot, apparently. Sometimes high RPM will bring the problem on. I had a module that I could cause to sputter and misfire by revving to over 3500 RPM. Turn the engine off and restart and it would go back to normal. I could drive around all day as long as I kept the RPM low.

I've seen a common recipe over on zcar.com for using the RRFPR with a turbo. It involves locking the timing on the distributor and using the RRFPR to dump fuel to prevent self-destruction. Crude, but apparently boost happens and the motor lives. You might get more help over there.

5. The low beam/high beam problem is actually more likely from the dimmer switch/turn signal assembly. I fixed mine (same problem) by hosing the insides of the dimmer switch with CAIG DeoxIT, but I think that they can be taken apart and cleaned up also. I had planned to but the DeoxIT worked so well that I never did.

The screw next to the dashpot is the idle adjustment screw. It lets air past the throttle blade. If you can tune it with no effect, it is either so far out that the screw is not in the air flow path anymore or you have another path past the throttle blade, like a vacuum leak or the AAR is stuck open. Crank it all the way in, and if nothing happens check for those two problems. I wouldn't mess with the AFM until you get full control over air to the intake manifold. You'll just make a big mess, and end up going to carbs or trying Megasquirt. Popping back through the intake is also a fair sign of lean, which could also be a vacuum leak or plugged injectors or low fuel pressure...

Why do you need an "upgrade"? Have you considered a straight replacement with a working stock-style alternator? Many auto parts stores will test your alternator and your battery, in the car, for free.

The yellow and red paint is at a lower RPM on the 280Z tachometer than on the 240Z tachometer. Therefore....