Fuel Pressure Gauge Needle Shaking
 

Recently I've had some hard starting issues. I bought a new fuel pressure gauge and the needled shaking almost =/- 10 psi. I never noticed this before. I took apart the aeromotive pressure regulator and the diaphragm seems fine.
I am about to drop the tank and replace the pump.
Any thoughts?
https://photos.app.goo.gl/MU3ZwhZ1UKzJFmRZ6

Re: Fuel Pressure Gauge Needle Shaking
 

Try the gauge on other cars? Did you remove the pulse dampener? -thoughts-

Re: Fuel Pressure Gauge Needle Shaking
 

I don't have another car to try the gauge. My original gauge showed the same readings, but the shraeder connection broke while testing. I bought a new gauge and the readings are the same. Also, I did replace the fuel filter?
Are you referring to the pulse damper next to the fuel pump? The car still had the original pump assembly.

Re: Fuel Pressure Gauge Needle Shaking
 

Are your pressure gauges small "peanut" sized gauge vendors sell and sometimes giveaway for the fuel line? Those are junk gauges. The Harbor Freight fuel pressure gauges are junk to. The HF gauge I had to return because it would stick right in the middle of it's range.

Get a good quality gauge before you buy any parts. Most auto parts stores lone them out.

Re: Fuel Pressure Gauge Needle Shaking
 

Well the pressure gauge I use is made by Actron. About 10 years ago I worked for Actron/SPX in Cleveland as a manufacturing engineer. Left the company just before they moved most of their manufacturing to China. Then I worked for GE where I set up a medical device service line in China.
Getting back to reality, I think the gauge is correct because I also had hard starting, Code 54 on EBL and lean WB readings. However, I never saw the gauge shake like that.
I bit the bullet, dropped the exhaust, rear end and fuel tank the last 2 days. I put in the new fuel pump and the pressure rose quickly. Just need to put it back together.
Thanks for the all the inputs. I really hope the damper is ok, since the tanks is already installed.

Re: Fuel Pressure Gauge Needle Shaking
 

Update - Replaced the fuel pump and pressure steady with no shaking.

Re: Fuel Pressure Gauge Needle Shaking
 

LB87,

Thanks for that update. My fuel gauge is shaking sometimes too, bouncing around, within a ten psi range, like 21 to 31, fluttering, actually. More evidence my fuel pump is going bad.

Re: Fuel Pressure Gauge Needle Shaking
 

GTA88,
Changing the pump made a huge difference. I've been programming with the efi and I have to change all the VE maps. Engine runs smoother and faster. Are you able to see the video link I included in the first post? If so I will post a video with the new fuel pressure.

Re: Fuel Pressure Gauge Needle Shaking
 

LB87,

No, I can't play the video, but thanks anyway.

Good to hear that the fuel pump improved things! I'm going to have mine replaced soon.