Before I even talked to you I ran it with the gas cap off, still dropped.
Yes, it is a liquid filled fuel pressure gauge in the engine compartment.
A liquid filled gauge will become innaccurate with heat. Been there, done that. Order a non liquid filled or a universal gauge and verify before you spend any more time or money.
Todd is right, liquid filed gauges can be inaccurate due to heat or altitude change. Some gauges have a vent screw on top. Make sure not to let any of the liquid out. Now, turn the screw two or so turns out to equalize inside gauge pressure(NOTE.. some gauges have a little rubber plug that you maybe able to remove insted of a screw).
This will allow the gauge to release un-wanted pressure and self adj to different altitudes or temperature. I used to have to do this at different race tracks with my gauges. Oil filled is good for vibration but can suck for accurate readings.
Ron Sutton is also right, It could be your regulator. I have had the diagram ones lose pressure and you have to adjust accordingly. You said you replaced the fuel pump so I doubt its the bypass (if any) in your pump.Some pumps have an adj pressure screw..is that set right?
Another thing... are your hoses old? Maybe they are coming apart inside and tiny bits of rubber are in your regulater. This is just my 2 cents..Hope you find it
Also..For safety sake... I do not like to run a fuel pressure gauge under my hood they can leak JMOHO
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If it ain't buckin, chirpin & makin all kinds of bad noises, then I ain't happy
Accelerating is optional...........stopping is mandatory. Your car WILL stop one way or another.
Wow guys, really great responses and ideas. THANKS
The liquid filled fuel pressure gauge is brand new, but I will check it and attempt to equalize the pressure or adjust if there is a screw.
As far as the regulator theory, I don't have one. The fuel lines from where they come off of the hard line are all brand new.
The only performance issue is due to the fact that I have a brand new carb on the car which is not dialed in yet. The car starts fine, idles great.
My theory is that the filter sock on the pickup tube of the sending unit may have been compromised by the ethanol in our fuel around here. I had some serious corrosion issues with a previous Holley Street Avenger (yes Mr. Weld I know!!). I've purchased a new sending unit and will be here early next week.
Most of the time It's not that the liquid filled gauge goes bad because its new or old,(unless you drop it or beat on it lol) it's that it builds pressure and can give a false reading.
So by backing the screw or removing the plug, you release this pressure. I have used so many different fuel gauges form brand name Co's and they all differ by about 2-3 even 5lbs in pressure. Pick one and tune your engine to it and that is that.
I didn't read that it may be inside your gas tank, I hope it's an easy inexpensive fix for you
__________________
If it ain't buckin, chirpin & makin all kinds of bad noises, then I ain't happy
Accelerating is optional...........stopping is mandatory. Your car WILL stop one way or another.
Most of the time It's not that the liquid filled gauge goes bad because its new or old,(unless you drop it or beat on it lol) it's that it builds pressure and can give a false reading.
So by backing the screw or removing the plug, you release this pressure. I have used so many different fuel gauges form brand name Co's and they all differ by about 2-3 even 5lbs in pressure. Pick one and tune your engine to it and that is that.
I didn't read that it may be inside your gas tank, I hope it's an easy inexpensive fix for you
The sending unit will require dropping the fuel tank which I don't look forward to. The sending unti was only $70 shipped. It could be worse!!
A liquid filled gauge will become innaccurate with heat. Been there, done that. Order a non liquid filled or a universal gauge and verify before you spend any more time or money.
Brian Hobaugh SCCA National Tour June 2014
First Hemi 'Cuda Convertible Ever Built
Short clips: Goodguys Pleasanton autocross and pit videos
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