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

[mbz]

35 minutes ago, Dave WM said:

hook up the FPR ONLY to where you attached the line from the gauge to the fuel rail (taking the rail out of the equation completely) hook up the return line from the top of the FPR to the bucket, block off the other side of the FPR. Testing JUST the FPR now to see where is hold pressure with no vacuum.

OK I did the Fuel Pump only to FPR test and got 42 psi with key on and 38 psi with key off. ( said 40 psi in the video but couldn't get a good reading until I saw the video).

To be sure I got the test set up and performed correctly.....

See video #1 for test results.

See video #2 for test set up & configuration.

Edited April 14, 2019 by mbz

[Zed Head]

Your gauge has a 2-3 psi offset from the beginning.  Have you ever seen the needle on zero?

[mbz]

29 minutes ago, Zed Head said:

Just for reference, most of us would connect up a gauge, get the pump running, and the needle would jump to 36 - 38 psi and just sit there.  Nice and steady, within seconds.

I get it..... I need to borrow a gauge from Manny, Moe & Jack and see what results I get with a different gauge.

[mbz]

2 minutes ago, Zed Head said:

Your gauge has a 2-3 psi offset from the beginning.  Have you ever seen the needle on zero?

Yes it goes to zero, it's just the angle of the dangle in the photo that's making it look like it's starting at 2-3 psi.

[Dave WM]

I will do the same tomorrow. how did the flow look? was it coming out like a fire hose?

[mbz]

4 minutes ago, Dave WM said:

how did the flow look? was it coming out like a fire hose?

I couldn't see. I was in the driver's seat turning the key.

I didn't hear Niagra falls over by the bucket, in other words it didn't sound like it was gushing or anything.

Just for shits and giggles, I could hook up the original FPR and see what happens.

So what's the next step from here....?

Borrow Fuel Pressure Gauge from MMJ?

Buy a Vacuum gauge and see what kind of vacuum is present?

Am I jumping the gun again?

I'm not sure what this test told me other than my Fuel Pressure Gauge is a POS.

Edited April 14, 2019 by mbz

[Zed Head]

8 minutes ago, mbz said:

Yes it goes to zero, it's just the angle of the dangle in the photo that's making it look like it's starting at 2-3 psi.

The silver thing is the needle stop.  It's set at zero.

[Dave WM]

yea try the OE one. see if you get the same results. What you got from the test is you get the same high pressure reading with out the rail so its NOT a rail restriction issue.

If you watch my video early on you see how its supposed to act, jump right to 38 psi and hold there. 1# rule of diagnostic, make sure your test equipment is in good working order. I hope it is the gauge at this point since there are no other options to pursue.

[mbz]

2 minutes ago, Zed Head said:

The silver thing is the needle stop.  It's set at zero.

Zed for your edification, here's a head on, dead on shot of the gauge at zero.

[rcb280z]

I agree with Zed Head on the 2-3 psi, needle is not on zero. I would get a new gauge

 

Haha! mbz, Glad you posted that. Optical illusion. 

 

Edited April 14, 2019 by rcb280z

[mbz]

3 minutes ago, Dave WM said:

1# rule of diagnostic, make sure your test equipment is in good working order. I hope it is the gauge at this point since there are no other options to pursue.

OK I get it. I'll borrow a gauge tomorrow and see what happens.

However, gauge or no gauge, the problem is still persistent.

That's pretty high pressure.

Not sure what's next......

[mbz]

1 minute ago, rcb280z said:

I agree with Zed Head on the 2-3 psi, needle is not on zero. I would get a new gauge

Again......