ZguyECV

Ok working on my 76 280z. So I’m getting this car ready to get on the road and run for smog check. Usually 2nd or 3rd crank shed fire up and run pretty good had some surging once to op temp, but I thought it was only due to the boot between the AFM & TB being pretty tore up and obviously loosing air flow. So I did a basic tune up cap, rotor, plugs, wires, and repaired the boot. Fired up as normal but starting an odd chirping sound on the right side (like a bird was in the engine bay lol) so I as I was looking around for the noise thinking it could be like a pulley bearing or something like that it kinda sounded like it was coming from the valves and then started hesitating and died kaput. So I pulled the oil cap off just to peek inside idk why really. She did fire back up after a lil fight. More chirping and would change in pitch get louder and almost go away. I left the oil cap off on refire. Did some more looking course I really couldn’t see anything so I went to put the cap back on and shed start to hesitate again sure to die. So I popped off the hose for the pcv and put the cap on ok no problem stuck my finger over the hose and it dies.

I know this is getting long but trying to add all the info I got...

So I go ahead and pull the VC off figuring ok its going to need a valve job right. So I find a few cam lobes warn and obviously tight so I know either the intake or exhaust valves or both aren’t closing or opening correctly. I also found a few of the lobes were dry like no oil had been getting to them. They were the ones pretty beat up...

So my question is. For all of u, with the expertise on these L28 ss’s. How does the oil get to the lobes? Do you think the valve job would solve this situation the oil and dying or am I dealing with something a little deeper then that? I know I’m on the right track of course put don’t have the experience behind me on these engines. I could use a link to a good write up for the valve job, hence I still haven’t received my book yet and I was unable to find one on my search. I’m obviously not good at searching the site because I’m sure this has been gone over more then once lol

So thanks for reading and all suggestions tips and info muchly appreciated thanks Guys!!

NismoPick

Is the oil fresh?
How long has the car sat w/o being run?

My 280ZXT ate a cam on my way home from MSA 07 (died outside of Barstow @ 1AM). Turns out part of the problem was REALLY dirty oil which caused some cam oil ports to be clogged.

ZguyECV

the oil is fresh. It did set for along time. it looked pretty new when I got it home but I changed it anyway.

huh took me an hr to read the gun tread lol

ZguyECV

Still couldnt find a tread for the valve job anybody got a link?? or an explination through it?

So start at tdc or bdc, at #1, 360' around or 180'? whats the gap to be at cold and hot?? couldnt find this info in the fsm download either, god I must be blind. lol i prefer books

NismoPick

Valve jobs are done by machine shops... unless you have a machine shop in your back yard.

If you mean adjusting the valve clearances, click here: https://www.zdriver.com/forums/240z-280zxt-s30-s130-tech-tips-275/aftermarket-cams-cam-removal-installation-pics-19939/
Specs are in the FSM & Haynes manual... plus I've posted them before.

TDC is TDC at cyl# 1 and 0 degrees.

ZguyECV

lol yea I wish I did!! and yea thats what i meant. Like I said im sure it had been posted way more then once. just being blind. Actually feeling pretty bloned at the moment cuz itd be the same as the zx right both L28 right **SLAP DOOOHHHH!!!!**

ZguyECV

Ok upon a lil more research and inspection before starting any work found that my bird chirping away was a twisted lash pad on the #1 cylinder exhaust valve Not to sure on how this was even possible to happen with doing a basic tune up and sealing up the boot because it wasn’t there before or it was and just wasn’t making noise. Nice right. NOT. Also found that the lack of oil was due to the oil cam tube is clogged at the left side of the front run giving partial deliver to the #3 cylinder intake valve and none to the exhaust valve. Wiped down the tube and used a mini wire brush to clean the out the rest of the rockers got full flow to the rest but # 3 remained the same. So I adjusted all the valves cold squirted some oil on #3s rockers and lobes ran it. As she was warming up checked for the air flow problem. Caped all back off as its suppose to be, adjusted idle speed and she quit dying but Boils down to a bad afm now I had cleaned the guts and connections when I repaired the boot Tried to move the sensor guide off the 2 groves but was unable to break them loose. So I didn’t reseal the lid and I’m glad I didn’t seams to have a dead spot at idle bout the spring tension seems really weak catches good idle for a few sec's 10 or so at best but the counter weight bounces big time and idles all over the place. Now would the advance have anything to do with the amf? No right just measures air flow advance is to the dizzy right?

pulled back off the valve cover checked and readjusted as needed hot.. Good to go. So that’s where I sit got pull off the oil cam tube clean it. Be easiest to get an afm and go from there. Thanks for the info bed time