1977 280z EFI Nightmare

[ckurtz2]

Copy. I will go figure out a way to hook up the vac to that and update you. The AC fitting was too small for it and the brake booster was too large

[zclocks]

I've tried to follow this thread and it appears you a have a lot going on. Been there and done that . Don't give up you have to work one problem at a time and you will get there.

The valves should not make that much noise. If  they were adjusted correctly you should hear an even clatter. If they are tooo tight they wouldn't make much noise. In an earlier thread you mentioned spray bar gaskets. Do you have a spry bar on this car or do you have an oil hole in each lobe? you can't do both or you will have very low oil pressure.  If you have a very flat lobe you can not adjust out the noise.

Second it appears that you have NO vaccuun if i'm reading your gauge correctly. Where are you connecting the vacuum gauge? 

Third did you check the fuel pressure? The way use started the car it appears the pressure was low and it took three try to reach the 30 psi to start.

 

 

[ckurtz2]

@zclocksThanks for the morale boost. Definitely need it. Yah, I have no idea what is going on with the valves, but clearly it has issue. I will pop off the cover again tommorow and post my findings. It is just a spray bar that I had to make custom gaskets for. 

Thanks @Zed Head for the tip. So it turns out at 1k rpm I am getting 16Hg of vacuum. Maybe a little low, but the oil pan also pisses about a 1/5 of a cup of oil every night so I am sure that could be considered a small vacuum leak. I connected the gauge to the brake booster fitting on the intake.

Another good thing to note is when I rev it to full throttle the vac pretty much goes to 0 and when I let off it shoots to about 25

Edited May 21, 2021 by ckurtz2

[zclocks]

Hey, I think I see an open vac port. This should be plugged

[ckurtz2]

@zclocks my bad. Not sure where you saw that, but it is plugged now. Must have forgotten earlier when I was trying to figure out which vac port I could connect to.

[Zed Head]

You mentioned overtightened valves.  That is very bad.  It will make the engine run rough and if you do "burn" a valve, the valve is ruined.  You'll have to remove the head again.  So, I'd get on that right away.  Check your rocker arm wear pads and see if you can tell where the cam lobe is riding.  Wipe pattern.

Also, I don't know how you chose 18 degrees for initial timing.  10-14 is a common range for people trying to get a little extra power.  7 is the spec., I think.  18 is high.

[zclocks]

I snipped it from your video , but couldn't tell if it was plugged. A couple of vac sources are all vac lines suspect due to age, dip stick seal, pan gasket, maybe, cover plate, like where yours is plugged off on intake manifold. and valve cover gasket.

[Zed Head]

Here's an old thread about wipe patterns.  It's an enjoyable topic.

 

[Reptoid Overlords]

Might be a good time to pop that valve cover off and take several good pictures of the whole valve train for the group to observe. Perhaps even get a remote starter and post a video of the engine spinning no spark plugs/spade connector removed from starter.

[ckurtz2]

7 minutes ago, Zed Head said:

You mentioned overtightened valves.  That is very bad.  It will make the engine run rough and if you do "burn" a valve, the valve is ruined.  You'll have to remove the head again.  So, I'd get on that right away.  Check your rocker arm wear pads and see if you can tell where the cam lobe is riding.  Wipe pattern.

Also, I don't know how you chose 18 degrees for initial timing.  10-14 is a common range for people trying to get a little extra power.  7 is the spec., I think.  18 is high.

I will. I'll get photos and such to show everyone as well. Just getting dark here, so it will be tomorrow. I just found that at 18deg BTDC it seemed to run best, I didn't wan't to go higher. Lower the idle dropped and got a little rougher. I could raise it with the idle adjustment screw, but it still seemed to stumble more. The sticker on the hood says 10deg BTDC, which I assume is what it ran from factory. I can bring it back down to around there if you advise that.

[Zed Head]

It looks like you are past Nightmare though, the engine runs and revs and it seems like you're close.  Kind of in to recurring weird dream territory, like the one where you're naked at a job you used to have and nobody is really sure why you're there.  You guys have that one, right...?

[zclocks]

When that happens I usually say" I 'm here to take the secretary out to dinner!

Something else I saw in a previous thread about damper pulley. This is near and dear to me as I just had to do mine several months ago. The damper should not wobble.