fuelk pressure gauge needle fluctuation, bad sign?

[fdjizm]

I can't say exactly when this started, and it's not all the time.
the engine runs fine, the idle is steady, fuel pressure goes to 40 or so psi at wot as normal. But I guess once in a while I notice this needle fluctuating.

Here is a short vid of what it does, the rise to 35psi is just me touching the gas, but it will sit there and go from 28 to 30 back and forth... I'm pretty sure this never caught my attention before, what is this a sign of?



I will pay more attention to exactly when it happens and report back but anyone seen this? the car has 72k on it right now if that's any help, and I just changed the fuel filter 2 weeks ago.

 

[skwerl]

Electric or mechanical sending unit?

 

[fdjizm]

it's an autometer electric.

 

[BadHabit2Break]

Is that your turn signal clicking? If so, it seems to move with that.

 

[Weou09]

It almost looks like there maybe some interference with the blinker as it was moving with the same rhythm as the clicks.

 

[fdjizm]

Yea pretty weird I am going to see if it does it with the blinker off actually just noticed that lmao

 

[Fullboogie]

It's a dual purpose gauge - quit yer griping.

 

[fdjizm]

What's the other purpose? lol

 

[Fullboogie]

1) Fuel pressure; and

2) You left your blinker on, you idiot.

 

[fdjizm]

Touche' fucker, touche'.

Well I hope it's nothing bad :/

 

[skwerl]

1) Fuel pressure; and

2) You left your blinker on, you idiot.

 

[Fullboogie]

Kidding aside, I had a mechanical gauge do that back in the day on my Fox. I've never heard of an electric gauge doing that. I suspect it's the sending unit or gauge that's the problem.

 

[cm581978]

My guess is the sending unit

 

[stkjock]

Sending unit be my bet, happend on my oil pressure setup, found out its a common issue.

 

[fdjizm]

I will be happy if it's just the sending unit, if the fuel pump was going bad I would see some serious symptoms right?

 

[s8v4o]

What fuse did you tap into for it?

 

[fdjizm]

I think it was A5 in the passenger box, gotta take a look later..
So yea it's the fuckin blinker affecting the gauge, wtf... so it's affecting the gauge not the actual fuel pressure I assume.

 

[skwerl]

I would run the fuel pump wiring upgrade regardless. I think the fuel pressure should be about 39psi, unless your gauge is just off. S&H has the wiring kit with instructions for $35.

 

[fdjizm]

Fuel pressure goes to 40 on a WOT run, always seen 28-30psi idle on other cars too.
The wiring is a good idea though, def. not against that.

 

[BruceH]

When is the last time you changed the blinker fluid?