What's the accurate way to check for fuel pressure?

milesursogood · Post by **milesursogood** » 08 May 2011, 13:16

I've been told that if the fuel pressure is low, it will not open the injectors and give you the fuel needed to start & run the engine. Is using a pressure gauge between the fuel line and fuel rail the proper way to measure fuel pressure?

If I've identified both the fuel rail and the fuel line correctly, can someone recommend a standard pressure gauge that I can connect between these two? What's the 2nd line on the image that may appear to connect to the fuel regulator for?

I think I hear the hum of the fuel pump when I turn the ignition ON, fuel goes into the fuel rail, and a squirt of fuel comes out of the schrader valve when I depress it. But I could never get a standard tire gauge to get a reading off the schrader valve.

Post by **jblackburn** » 08 May 2011, 13:43

One of these will screw into the end of the fuel rail. The 0-15 psi are for older carb. cars so you need a 0-100.

http://www.autozone.com/autozone/access ... e/_/N-25a2

Post by **vjaneczko** » 08 May 2011, 20:17

milesursogood wrote:But I could never get a standard tire gauge to get a reading off the schrader valve.

That may be an indicator that your fuel pressure sucks! I can't remember who mentioned using a tire guage, but they do work - you just have to throw them out once it's been used as the gas will cause them to go bad.

milesursogood wrote:What's the 2nd line on the image that may appear to connect to the fuel regulator for?

Fuel return line. The rubber hose snakes its way behind and over near the throttle body.

urbex · Post by **urbex** » 09 May 2011, 01:32

jblackburn wrote:One of these will screw into the end of the fuel rail. The 0-15 psi are for older carb. cars so you need a 0-100.

http://www.autozone.com/autozone/access ... e/_/N-25a2

Oh dude....overkill

Plus it will be a pain to deal with for basic testing.

Get a gauge meant for testing duties - http://www.autozone.com/autozone/access ... =84174_0_0_ In fact, most of the auto parts stores around here have a version of these things on the loan-a-tool program (where you "buy" their loaner, by fronting the purchase price, do whatever you need to do, then return it for a full refund). Sure, they've probably been abused by the previous people that have used them, but it will be good enough to verify basic functionality of your parts. Or, just buy a new one for the $45