daughter.and.datsun

@NewZed Ah! Forgot to mention new plugs (which are all receiving spark) and a cleaned and inspected/measured distributor cap. The engine seems to be functioning well. I'll post a video next time I give it a go. It seems to move through gears smoothly (I last took it up to about 3rd trying to get above 30mph on a flat road), and the tach moves smoothly through RPM, but it's just as if the output power curve has been adjusted down to near nothing. Things sound smoothish too (aside from a singular rev-matching clicking sound coming from around the engine). All good sugges

@NewZed Is there any good way to check if water is in the tank? My sender float is likely bad, so I was going to drop the tank sometime soon to investigate that. Any notoriously bad gaskets or anything I should look out for? Again, thanks to you both. This is an interesting line of investigation!

Thanks for the suggestions! @NewZed, automatic, 4 speed. The water idea is very interesting. I was driving it daily at the beginning of this year, but I stopped doing that around February (working from home). It's also right around then that it stopped delivering power... The rubber on this car is real bad, and it wouldn't surprise me at all if the gas tank was leaking. What would be included in a "tuneup"? Within the past 6 months I've done everything mentioned in the original post, plus replaced engine+trans oil, oil filter, fuel filter, thermostat, flushed engine coolant +

I'm trying to diagnose a few things on my 75 280z 2+2, and I'm wondering if they might be related. Any help would be appreciated. Also, does anyone know why the section of my camshaft above cylinder #2 is red? Video. In summary, I can't seem to get power out of my engine. It used to run "great", but now I can barely get the car over 30mph. I ran a compression test, fearing a blown head gasket, but though the readings aren't great, I would have expected to get over 30mph with them (1: 170, 2: 156, 3: 167, 4: 169, 5: 160, 6: 165). That #2 cylinder seemed especially low,