Fuel Pressure Drop

MaSSaCrE · Post by **MaSSaCrE** » Fri Jul 17, 2009 8:34 pm

Alright hooked up the fuel pressure gauge today and my fuel lines shows about 7-8psi when the fuel pump is on but car is not cranking over which even at that level of psi its still a hair to low for normal tbi psi.

Well right when i turn the engine over the psi drops to like 1-2 and I was curious if anyone had some suggestions on the different possibilities it could be. Already planning on looking over the fuel lines for kinks and clogs. I already know the fuel pump could be one of the top things but i was curious in any other possibilities.

The injectors might spray a very very very light mist every two to three seconds .

Waffles · Post by **Waffles** » Fri Jul 17, 2009 9:02 pm

7-8 PSI seems WAY LOW for any injected app.

If it is correct, it sounds like your battery does not have the power to run your starter and fuel pump.

EDIT: just looked it up, it does run at that low of a pressure....

MaSSaCrE · Post by **MaSSaCrE** » Fri Jul 17, 2009 10:12 pm

Correct tbi runs low but not 7-8 it should be at least 10-12 and even 1psi off would stop it from staying running. Did plenty of research of tbi systems. Battery could be a little prob but not exactly my best bet since its being jumped and still wont do shit.

Waffles · Post by **Waffles** » Fri Jul 17, 2009 10:31 pm

Takke the batt to AZ and have it charged/tested and rule it out. After that i would start looking into your wiring/grounding

MaSSaCrE · Post by **MaSSaCrE** » Fri Jul 17, 2009 11:51 pm

Yeah i ran through a little bit of wiring today. Started from the injectors and starting going through. More then likely its the pump but who knows.

MaSSaCrE · Post by **MaSSaCrE** » Thu Jul 23, 2009 6:20 am

Possibly the fuel pump is not pushing the requirements i need maybe i should up it?

qwarnon · Post by **qwarnon** » Mon Dec 07, 2009 12:42 pm

Either:

1. junk fuel pump
2. clogged fuel filter/filters (usually one in tank that is a screen, one or 2 past the pump.
3. bad fuel regulator.
4. too small of fuel line.
5. leaky injector?

If you havent replaced or checked the fuel filters (at least the one outside the tank, they clog/get old more often), id try that. its cheap and easy