“Chugging” noise.

[moozieman]

Looking to address this weird “chugging” air noise on my 78 280z. I’ll attach a video. Take a listen and let me know what u think.?

[gwri8]

Right off the bat I see a big vacuum leak. With that air filter on the valve cover you're getting unmetered air. The hose that connects the throttle body to that location is missing.

[Pilgrim]

Nothing screws up the idle like a vacuum leak. As noted above, that filter on the valve cover opening is bad news, and a major vacuum leak.  It's a pain to trace and check the vacuum hoses on these engines, but they are often the problem.

Edited June 20, 2020 by Pilgrim

[moozieman]

On 6/20/2020 at 12:46 PM, Pilgrim said:

Nothing screws up the idle like a vacuum leak. As noted above, that filter on the valve cover opening is bad news, and a major vacuum leak.  It's a pain to trace and check the vacuum hoses on these engines, but they are often the problem.

I had mentioned this in a previous thread, the previous owner plugged up the breather port on the block with a freeze plug. Therefore I have no pcv valve. I added that filter up top to act as my vent

 

[moozieman]

this car is giving me so many issues. Doesn’t accelerate over 2k and dies on hills, not to mention it burns through spark plugs.

[moozieman]

It runs and drives decent fine with brand new plugs, but they only last about 8 miles MAX.

[Zed Head]

Did you do this test yet?  Below.  And check the vacuum line to the FPR for fuel.  It might have a blown diaphragm.

[moozieman]

1 minute ago, Zed Head said:

Did you do this test yet?  Below.  And check the vacuum line to the FPR for fuel.  It might have a blown diaphragm.

I’m confused. This test is for water temp sensor? (Which btw, my thermotime and water temp are unplugged) (it doesn’t run otherwise.)?

[Zed Head]

Yes, if the water temperature sensor is disconnected the ECU will supply maximum extra fuel.  That's probably why yours is running so rich.

If it doesn't run when it's connected it might be because it is shorted out, making the mixture as lean as possible.  Or because you have a large vacuum leak, maybe through the PCV system.

People often mess around for weeks or months trying to avoid doing the tests.  But there's a reason that Nissan created a completely separate book, very detailed, with instructions, illustrated, covering all of the years from 1975 through 1980, and published it.

 

[moozieman]

7 minutes ago, Zed Head said:

Yes, if the water temperature sensor is disconnected the ECU will supply maximum extra fuel.  That's probably why yours is running so rich.

If it doesn't run when it's connected it might be because it is shorted out, making the mixture as lean as possible.  Or because you have a large vacuum leak, maybe through the PCV system.

People often mess around for weeks or months trying to avoid doing the tests.  But there's a reason that Nissan created a completely separate book, very detailed, with instructions, illustrated, covering all of the years from 1975 through 1980, and published it.

 

How should I test for a short? It’s usually unplugged because of how rough it runs when it’s plugged in.

Edited June 26, 2020 by moozieman

[Zed Head]

Just now, moozieman said:

How should I test for a short?

[moozieman]

Appreciate the advice ill take another look. It appears as tho one of the temp components is actually broken off.