Marginal fuel pressure - 4.6 2v 03 GT

[jamessr23]

Car seems to be down on power. No CEL lights. I borrowed the O'Reillys fuel pressure test kit. I hooked it up...cracked the key to run/no start had 0 pds on the gauge. Started the car it stayed at 32pds...when I did a few 1-3K revs it went to 35 pds...shut the car off it went back to 32pds...stayed at 32 for over 15 mins...

Seems marginal to me. Should I invest in a FPR to boost it to 40 psi? I have 24 pd injectors.

I am a novice so please don't kill me in the comments

 

[96blak54]

I think your fine.
Increasing fuel pressure is essentially adding more fuel and by doing so without tuning the computer will mess with how the car responds and the response will be a negative one that you dont want.

Best to do a tune up and/or sensor cleaning, oil change, and such

 

[jamessr23]

Thanks for the feedback...when you say sensor cleaning..are you saying just the fuel pressure sensor or the mass air sensor etc as well?

 

[Rolltide1006]

Thanks for the feedback...when you say sensor cleaning..are you saying just the fuel pressure sensor or the mass air sensor etc as well?

Check/replace the fuel filter too if you haven’t already.


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[01yellercobra]

Your car doesn't have a fuel pressure regulator. It's a returnless fuel system. Meaning the fuel only goes to the engine. There is no returning extra fuel to the tank. The ECU controls how much fuel is being delivered by speeding up and slowing down the fuel pump. So on a normal pressure gauge it'll look like the pump is failing. A better way to check is to datalog with a scanner and watch Fuel Pressure Drop Across Injectors and Fuel Pump Duty Cycle. Those two will give you an idea of the overall health of the pump.

That being said 32psi is normal. Especially at idle.

Chances are you just need to do a tune up as mentioned. New plugs, fuel filter, air filter. Or clean the air filter if you have a reusable type. And clean the MAF sensor while you're at it. They make cleaners just for that purpose.

 

[jamessr23]

Thanks for the feedback 01Yellercobra. I have a newer Airraid Intake so I think I need to attack the MAM and the fuel filter. The plugs are a year old.

 

[01yellercobra]

How many miles are on the plugs? Was the car tuned for the bigger injectors?

 

[AStangThang]

Very normal psi. Looks like a lot of new member are coming over from other forums. I think we found our home.

 

[AStangThang]

Baby that MAF, don't soak it down or be rough. If your going to keep the car for a while, its time to do preventative maintenance, so crap like this doesnt happen in the winter. Its the best maintenance