1976 280z engine runs rough then dies, will not idle.

[Dave WM]

4 minutes ago, madkaw said:

You really the pressure is “way too high”. 2psi could be a gauge . Doubt that is any issue with his engine running poorly . 

watch the video. his video, not mine.

Edited March 25, 2019 by Dave WM

[mbz]

Just now, madkaw said:

How do the plugs look?

Plugs are filthy, see earlier in thread.

[madkaw]

I’ve gotten confused about the plug pics. I thought you said that was an old pic. If so did you clean them and recheck? What did they look like after this last run ?

[mbz]

9 minutes ago, madkaw said:

I’ve gotten confused about the plug pics. I thought you said that was an old pic. If so did you clean them and recheck? What did they look like after this last run ?

The first pic that I posted of the plugs was the OLD spark plugs.

The second set of pics I posted are of the NEW spark plugs. I posted the pics of the new plugs earlier this week (Tuesday morning).

The old plugs are the Bosch, the new plugs are the NGK.

I did not clean the plugs, I figured they have told me all that they need to (too much fuel in the engine), which was confirmed by taking the oil cap off the valve cover.

Checking the spark plug cables, the ignition coil and the distributor was really just a matter of good measure to be sure those are in working order and not contributing to the problem.

Edited March 25, 2019 by mbz

[Zed Head]

1 hour ago, Dave WM said:

did you check it with the engine OFF and the fuel pump running. do this by removing the start solenoid spade connector (so the starter will not operate when turning the key to the START position. while holding the key in the start position get a reading. You should hear the pump running.

Note the fuel pressure. Should be 36 psi.

Do that and report back. One step at a time. I have some ideas as to what the issue is, but its best to not speculate with possible solutions until test results known.

This is your next #1 thing to do.  The whole EFI system is based on a certain fuel pressure.  

[mbz]

5 minutes ago, Zed Head said:

This is your next #1 thing to do.

Yes I'll do it when I get some time this week, next available opportunity.

I tried to take care of 2 tests with 1 test in an effort to be more efficient with my time. (fuel pump & engine running fuel pressure).

I didn't think anything of it because I figured if there was not sufficient fuel pressure it would show on the pressure gauge.

Also figured that since the engine is running rich, the fuel pump must be functioning otherwise I would be experiencing a lack of fuel problem (running lean).

Edited March 25, 2019 by mbz

[Zed Head]

3 minutes ago, mbz said:

I didn't think anything of it because I figured if there was not sufficient fuel pressure it would show on the pressure gauge. Tried to take care of 2 tests with 1 test in an effort to be more efficient with my time. (fuel pump & engine running fuel pressure).

You ended up with 1/2 instead of 2/1.

[mbz]

4 minutes ago, Zed Head said:

You ended up with 1/2 instead of 2/1.

Edited March 25, 2019 by mbz

[Dave WM]

One last thing, you did replace the vacuum line on the FPR to the intake manifold right?

[mbz]

25 minutes ago, Dave WM said:

One last thing, you did replace the vacuum line on the FPR to the intake manifold right?

Yes, I had a replacement hose handy when I took the old one off.

I kinda figured I'd need to slice it lengthwise to get a good look inside it, thus rendering it useless.

That little hose is kind of a PITA to get back on!

[mbz]

Ok got a chance to test fuel pressure today (just the fuel pump this time.... engine NOT running).

35.5 psi




Sent from my iPhone using Tapatalk

[Zed Head]

Is that with a full battery charge?  Weird that you had high readings before.  

Your previous high readings could really only come from having pressure on the vacuum line instead of vacuum, or because your pump in the reading here, above, has low voltage and is runnng slow.

Another test would be to disconnect the vacuum line and start the engine.  Rev it up a little bit to be sure that you have full voltage.  If it's a voltage issue pressure will rise.  Then reconnect the vacuum line and reconfirm the high readings that you had before.