Zed Head

Interesting. @brunodoggy ?

"Will I be able to drive my car" seems kind of like a small concern, considering all. Read around the internet about tetraethyl lead. There are still people out there that think that lead poisoning is not a big deal and "big government " is ruining the joy of 12:1 compression and big cams. https://www.aoghs.org/products/tetraethyl-lead-gasoline/

Not The Rapist, he's leaving. A rapist. I was like "who are these guys and what are they doing now?"...Google ...tap tap tap ...Wikipedia...read read read...crap...Google....read more...seems to be a date raper...can't be associated...edit.

Check the engine's grounding. Maybe it's poor so the gap across the spark plug electrodes is not the path of least resistance. Actually, check the resistance of the head to ground, the battery negative post or the alternator case, or both, since the head is what the spark plugs ground to. Just looking for odd reasons that lifting the cap has an affect. But, a new clean cap is probably the best first step. The turbo distributor uses the two screws to lock down so you can't really get it mixed up with NA. The local parts stores sell the same parts as Rockauto. Just a little bit more expensive. Get new wires also. https://www.oreillyauto.com/shop/b/ignition---tune-up-16776/distributor-cap---rotor-16854/distributor-cap-12506/a0b4d83dd803/1982/nissan/280zx?q=distributor+cap

I've never heard of the "running compression" test. I'm not sure that's a valid test of anything. The throttle valve will be closed and the intake manifold under vacuum. Edit - The Google says it's a thing. Haven't dug in to it but I think you still need to compare cylinders, not just do one cylinder. Your "normal method" test results look good. I don't really see a problem being described. Even cylinder pressures, runs well, gets in to boost, etc. What is wrong?

You said that you got about 130 psi in your other post. So, we can't really tell what's going on. A list of all six pressures would be good.

That's a $250,000 car. Funny, but Pierre Z worked on it prior to the auction. He worked on the 31k mile Z. Did you put those wheels on it?

Looks fine. They got a little too specific I think on continuity and open circuit. A problem there would be more noticeable while driving anyway. Never hurts to take a step back and see what you've learned since you decided that there was a problem. The lifted distributor cap is still a very odd thing.

Is this a thing? L25?

So many Z's, of all numerologies, have popped up that I thought it might be good to collect them here. Feel free to add old or new stuff. There's a bunch out there right now, for some reason. https://bringatrailer.com/listing/1975-datsun-280z-26/ https://bringatrailer.com/listing/1976-datsun-280z-38/ https://www.classiczcars.com/forums/topic/64614-1270-on-ebay-barn-find/ https://www.classiczcars.com/forums/topic/62501-brand-new-280z/ https://www.classiczcars.com/forums/topic/64653-1970-nissan-fairlady-z-hs30-03647-on-craigslist/ https://www.classiczcars.com/forums/topic/64539-31k-miles-series-i-240z-up-for-auction-on-bat-over-100k-on-first-day/ Edit 11 9 20 A couple of new ones. https://bringatrailer.com/listing/1971-datsun-240z-158/11 10 A confused ZX is up... https://bringatrailer.com/listing/1979-datsun-fairlady-280z/ 11 11 Another 78 https://bringatrailer.com/listing/1978-datsun-280z-79/ 11 12 The 355 76 280Z - thanks ollie. There are a lot of Z's popping up. Reminds me of right after I got mine and the wrecking yards always had something. No more. https://bringatrailer.com/listing/1976-datsun-280z-39/ 11 21 https://bringatrailer.com/listing/1973-datsun-240z-145 https://bringatrailer.com/listing/1973-datsun-240z-137/ 11 25 https://bringatrailer.com/listing/1972-datsun-240z-141/ 11 27 https://bringatrailer.com/listing/1972-datsun-240z-151/ From lonetreesteve https://denver.craigslist.org/cto/d/henderson-1972-datsun-240z-low-miles/7225870950.html 11 28 From lonetreesteve's post https://kansascity.craigslist.org/cto/d/kansas-city-1973-datsun-240z-parts-or/7237380548.html https://bringatrailer.com/listing/1981-datsun-280zx-turbo-6/ 12 1 https://bringatrailer.com/listing/1978-datsun-280z-80/ 12 4 https://bringatrailer.com/listing/1972-datsun-240z-156/ https://bringatrailer.com/listing/1973-datsun-240z-146/ https://bringatrailer.com/listing/1974-datsun-260z-40/ 12 7 https://www.ebay.com/itm/1971-Datsun-Other/264964354469?_trkparms=aid%3D888008%26algo%3DDISC.CARDS%26ao%3D1%26asc%3D20200220090753%26meid%3Dae4f76d8b3594d12a34b0f7e4337eeb2%26pid%3D100009%26rk%3D1%26rkt%3D1%26sd%3D224263144994%26itm%3D264964354469%26pmt%3D0%26noa%3D1%26pg%3D2047675%26algv%3DDiscV1&_trksid=p2047675.c100009.m1982 https://www.ebay.com/itm/1971-Datsun-240Z/224254524928?_trkparms=aid%3D888008%26algo%3DDISC.CARDS%26ao%3D1%26asc%3D20200220090753%26meid%3Dae4f76d8b3594d12a34b0f7e4337eeb2%26pid%3D100009%26rk%3D1%26rkt%3D1%26mehot%3Dpp%26sd%3D224263144994%26itm%3D224254524928%26pmt%3D0%26noa%3D1%26pg%3D2047675%26algv%3DDiscV1&_trksid=p2047675.c100009.m1982 12 8 https://bringatrailer.com/listing/1978-datsun-280z-22-7/ 12 9 https://bringatrailer.com/listing/1973-datsun-240z-150/ (lonetree's #155 post) 12 10 https://losangeles.craigslist.org/wst/cto/d/torrance-1970-datsun-240z-low-vin-738/7244637837.html (lonetree #150) 12 11 https://bringatrailer.com/listing/1976-datsun-280z-41/ https://bringatrailer.com/listing/1971-datsun-240z-162/ 12 17 https://bringatrailer.com/listing/1977-datsun-280z-48/ https://bringatrailer.com/listing/1978-datsun-280z-81/ 12 21 https://bringatrailer.com/listing/1973-datsun-240z-143/ 12 24 https://bringatrailer.com/listing/1972-datsun-240z-157/ https://bringatrailer.com/listing/1971-datsun-240z-156/ 1 1 21 https://bringatrailer.com/listing/1979-datsun-280zx-21/ 1 14 21 https://bringatrailer.com/listing/1973-datsun-240z-149/ 1 19 21 https://bringatrailer.com/listing/1982-datsun-280zx-17/ 1 25 21 https://bringatrailer.com/listing/1972-datsun-240z-159/ https://bringatrailer.com/listing/1981-datsun-280zx-19/ 1 26 21 https://bringatrailer.com/listing/1978-datsun-280z-84/ 1 27 21 https://bringatrailer.com/listing/1972-datsun-240z-163/ 1 29 21 https://bringatrailer.com/listing/1978-datsun-280z-82/ 2 1 21 (look at the date!) https://bringatrailer.com/listing/1973-datsun-240z-151/ 2 2 21 https://bringatrailer.com/listing/1972-datsun-240z-161/

I only posted that to clear things up about the switch. I'm not really sure what problem you're working on. Trying to change the appearance of a spark plug or make an injector sound louder is not a good target. If you're planning to just leave the cap propped up and run it that way then maybe removing and cleaning all of the spark plugs, or buying a new clean set would be worthwhile. Do that and see how things look now. You might be trying to fix a problem that doesn't exist anymore. Does it have running or performance problems with the cap propped up? What are they? If you're still worried about cylinder #6 then measure pressure on all six cylinders. It's easy to do and will tell you if the cylinder, piston and rings, are the same as the other 5. If 6 has low pressure then injectors or plugs won't help much.

Was it stolen? What did he do with it? More clues is more better.

Turbo different

Turbo engines have lower CR's. And gauges vary. It's the comparison of all six cylinders that really matters.

#6 looks wet and like it has not been firing much. The strap should be grayish-white like #5. Does it smell like gasoline? Something is not quite right.

My two main paths to any web site both worked fine. Google and typing in the name in the address bar then using CTRL-Enter to bring it up. You're back!

EuroDat put a paper together and has posted a lot about rebuilding. The parts are generally available. I think that you can get them cheaper than at ZCD if you search around. Seems like there are one or two sets of parts that everybody resells. There might be extra parts in a kit or a couple of missing parts, but the bearings and seals in the kits seem to be of good quality. The synchros can be questionable. Have you found any metal on the drain plug magnet?

Does injector #6 work with the cap up? Can't tell if you're saying that you got boost and up to 70 on 5 cylinders or something else. How does spark plug #6 look after boosting to 70 mph?

Might as well tie things together. A plan will form eventually. Keep original engine (block) and get more power seems to the heart of it. I saw "save money" somewhere also. Moderate budget power increase seems like the goal. I would avoid using words like drop or slap or toss when thinking about modifying your engine. People write like that often but only the pros can really do any dropping swapping or tossing of parts in engine work. Even just removing the crankshaft and honing the cylinders, then using new rings on the pistons and bearings on the crankshaft, is a complex operation for the average weekend mechanic. You're not going to drop in a new crankshaft, swap some pistons, and toss the engine back in without spending lots of money and time. https://forums.hybridz.org/topic/131952-ld28-crank-stroker-market-rate/?tab=comments#comment-1224639

Your ID looks right. It also has the dust/dirt shield over the slip yoke area. Which gear does it pop out of? There's quite a bit about shift lever interference causing 5th gear to pop out or not engage completely. Blown up bearings are common also.

If you have the old injector and a 9 volt battery you can jump the terminals and it will click if the solenoid and spring are working. You can use a 12 volt battery also but it makes some people nervous. Just tap the terminals, don't leave it connected.

Lots of good stuff in the FSM. Like the injector coil resistance, 2-3 ohms, and the injector opening description.

The light test is one way to see if the electrical connection is working. Many ways. Screwdriver on ear and injector, stethoscope, colortune, ...

Good luck.