Xenn

Zed head i said in op that both my alternator and distributor were 280zx swaps

Fuel pressure is fine, sprayed starter fluid as well and nothing, however, still getting no spark with the timing light. Now the weirdness, when i hook a voltmeter up to my ignition coil i get +12 volts out of both the positive and negitive terminals, and sometimes my positive terminal will seem to "cycle" from 0 volts back up to 12 then 0 again, i can understand my ignition coil being shot , but i dont know why i would burn through my second one in a few months, the last one was old and i expected to need to replace it, this one much less so.

Should both terminals have 12 volts on the ignition module?

I take that back, the problem simply hid, this morning it would not start when cold, so I connected the coil to the battery and barely got it to start, got it to work, now nothing, so I am going to head back and do a battery of tests, volt meter, timing light, starter fluid, go rent a fuel pressure gauge, all of that jazz, So I would list heat as only an exacerbator of the problem, not the cause since it was cold this morning, hopefully I can get it running and home to work on more. Also a thought I had, can you burn out ignition coils through having too high of a voltage run though them? My volt meter reads ~15 when running, I always figured it was just adjusted poorly (since it says like 13 when off) but It would be nice to know if it was a possibility.

Problem solved I believe, dieing fuse-able links. If it happens anymore ill post again.

I have before, I will double check to make sure I am not remembering incorrectly, also, my fuel pump is wired into a separate circuit that kicks on when im on ACC from when my AFM was dieing, so I can hear my pump going.

The dizzy is new, not a junker, however ill keep a can of CO2 in the car to check if its the relay or the ECU that is getting too hot, ill also pick up a spare next time I head out to a pick-n-pull. zkars, I will surely try your direct connect battery to ignition coil next time it happens, my guess is that is before the ignition coil, that would easily prove/disprove it. All the wiring between the distributor and ignition coil is new and soldered/heat shrunk, fresh spades, all that jazz, whenever I rewire something I try and do it right, ive had to replace too many "twist and electrical tape" faults in the car already. The big problem is it only happens at the hottest part of the hottest days (IE when im trying to go to lunch at work), so there is not much I can do when it happens, it is also very intermittent, only happened a few times, the first time I thought it was my ignition coil finally dieing so I got a new one and after installing it an hour + later it ran, however it happened again later with the new coil. Thanks for the feedback.

Also when the capacitor for the flashers starts to go it will blink faster and faster.

Things to look for: Wipers, if you have headlight problems as well, i would check the switch, if you get into it, pull the motor out and see if it still works, on mine the motor worked, but the scissor arms that connect to the wipers had rusted solid. Radio, check fuses, also aftermarket or no? If it is aftermarket check to make sure your ground connection is good and it has a good connection to the ACC. Fan motor, I upgraded to a honda civic motor and when I did I found out the previous owner had decided to do some rewiring under there, make sure all the connections are good between the heater controls and the fan motor, as well as anything that connects to the battery.

As per the two wired coming out of the firewall, my 280z is wired so that the heater fan is connected to the battery there. If your blower motor works fine then never mind, you might just wait until you have to replace the heater core to check it out. (Though my car is a hodgepodge of wiring I get to go through and fix).

When my car sits out in the sun for too long, it will crank but not fire, I hooked up a timing light and it would not flash so I know it is a lack of spark, Ignition coil is new, distributor and alternator are both new upgrades/swap (new 280zx parts wired in) so the ignition module and voltage regulators are both good, when the car cools down (the interior) it will start just fine. Any Ideas? (My only guess is a random separating connection or dieing ECU) 76 280z

She lives! Valve job, new timing chain, new gaskets, new rocker arms, new fuel pressure regulator, and cleaned everything up nice while I had it out. If I could offer any tips, it would be be very careful of the worm gear for the distributor, I had it off just a little and it screwed my timing for a day, i finally just lodged my rotor in the right place so it couldn't move, then fit the worm gear into it and the oil pump on that. Thank you all for your help.

For reference my '79 280zx has hardened valve seats, the mechanic seemed like that was standard because it was an aluminum head.

Good call on The retainer, I did not realize it was damaged until I looked really close and noticed a groove worn on the inside. The valve seat replacement depends on how much it costs, my life is a budget, but I am taking it in tomorrow to have it sured up and cleaned up, Ill ask how much that costs as well.

I took the cam itself out, apparently the cam towers are honed inline to make sure the cam doesn't wear badly, I meant to keep my rocker arms in order, however when I took them off I left the two that were compressed by the cam till last so I could have a friend help me and that threw off my system. Luckily my head looks fairly new, the cam and rocker arms show little to no sign of wear. My seats look bronze, but like I said my head looks fairly good, I will have a mechanic sure it up, and clean off my valves. BTW I cant check the stability of my valve until I get new keepers, I'm replacing the valve anyway because the end of it got chewed up by the broken keepers.

Darrel was closest, my 2 valve keepers became 2 halves of 1 valve keeper which got lodged between the valve stem and the retainer.

UPDATE: So I pulled the head, The valve in question is not broken off, however i can grab it and just spin it like its not under any real tension, I need to go rent a valve spring compressor before i actually remove it. I have a few questions though. Can I keep the camshaft in place easily while replacing the valve? Should I replace all the valve stem steals while I have it off? Can I take it to a machine shop to have it sured up with the camshaft still on and valves in? I have some corroded head bolts that need replacing, should I replace them all or just the bad ones, I know they are not stretch fit bolts and have been used before. I dont have an oil bar, is that a turbo only item? Im getting all new gaskets, do i need to put any silicone sealant on intake or exhaust manis, what kind should i use for them and the head gasket. Im sure I have one im forgetting. Like I said ive never done this before. This man wrote a better tutorial than I could have though.

Hmm, well tomorrow, im probably going to take the rocker arm off it and see if i can pull the stem out, ill have answers fairly quick then.

Also, if i end up going through the trouble of ripping the head off, what would you recommend doing while I had it open?

So sounds like pull head and hope for worn valve guide, the thing is i was able to do a correct valve adjustment not that long ago, i only thought I didn't fully tighten a locknut all the way down, it's when i went through, on the piston i knew had been running badly, that i found the valve spring...unrestrained? Not loose because the rocker arm against the cam holds it back. its suddenness is what makes me think its a broken valve or valve stem, and the fact that it is the only thing i know of that holds the spring.

I wouldn't say I know what Im doing, its more of someone mechanically inclined trying to restore a car worth restoring with minimal money and maximum will power. I haven't been formally taught, or worked on cars all my life, I work on my car, try to troubleshoot problems in a logical manner, fixing and replacing things as I go. Ive had this car for years, and do everything I can to keep it running/improving. So no I'm not driving it if I think anything fell in the piston, , especally a big chunk of metal. My engine had been getting louder so i thought it was a rocker arm working lose, it had an dd intermittent ticking today that seemed to go away at different rpm's, i opened it up and found this. Sorry if I sounded touchy about the valve adjustment, I did like 6 of them over the course of a couple weeks not that long ago when I thought I had a random lose valve before I realized it was my failing fuel injectors being obnoxiously loud I thought you meant rocker arm seat, not valve seat, I have not yet taken the head off, the engine was mostly rebuilt right before I got it, so I dont know there. Also if the valve head did come off, (and im planning on replacing the piston rings if i open it up) how scarred can the piston be before I have to replace it, I assume I would have to hone it out as well.

Its a 77 280z with the engine and transmission from a 79 280zx, the seats didnt look bronze but im not 100% Also I could press down on the valve spring and it would go down fine but always came up higher than it should

Ive done many vallve adjustments on that car, its been through a lot. Speaking of which, at some point that engine had been in an accident and the rocker arm for that same valve was knocked off and it was drove for a little while like that before I fixed it, so that valve already has the potential for damage. Yeah it was on the base circle, I go one step further than the chilton and have the cam lobes for each valve point up as I go, rather than setting the #1 up or down land adjusting 6 at a time like it says. .025m for intake .03 for exhaust, this is on an intake. #5, intake for cyl 3, which also had an oily spark plug And I set it like that because I got to that rocker, and the gauge wouldn't fit, so i started to loosen it to the correct position, it never got there, then i noticed the problem with the spring. I had no measurement to go off since I could not measure it correctly, so i set it as close as i could. Is the only thing that limits the valve spring the valve is what im asking? If so mine is probably broken somewhere.

Long story short, my engine was making an intermittent ticking, opened it up to make sure a valve hadnt gone lose form an adjustment I did a bit back and realized my #5 valve spring was completely extended, as in, did not stop pressing against the rocker arm even when the rocker arm was completely "lose" so I brought the exhaust valve next to it all the way down then counted the turns to get it adjusted to the right level for the other one that I could not adjust. Adjusted the other one to that point, then set the good one to its correct position and threw it back together. From my understanding of how the valves work, the only way that would happen with the spring is if the head of the valve broke off and has been eating my car all day, with the knowledge that the damage had been done already if that was the case, i turned my car back on and the ticking went away. Anyone have any clue what is going on? the only thing i could think of would be the valve stem broke and the piston has been tapping the valve back in *shiver*. Anyone have a less painful guess than that?

Sorry for the late update, got the battery tested, its fine, since we've had warm weather the problem has gone away. I am still stumped.