Fuel Pressure Gauge Install

Last updated: April 28, 1998

Date: Tue, 28 Apr 1998 10:41:38 -0400
From: "Robinette, Maj Robbie D."

Here's the latest How To from my web site. There are several pictures and diagrams that go with it at the web site. It's 3rd generation specific but it works pretty much the same way for the earlier cars. Instructions

Installing an engine-bay mounted fuel pressure gauge is pretty straightforward. You will need a 60 psi gauge, a gauge fitting for a 3/8 inch fuel line, and two, 3/8 inch hose clamps (preferably constant pressure "spring" clamps). I ordered the parts from Summit Racing (800 230-3030) for about $25. The gauge (liquid filled) and fitting are from Summit Racing, gauge - part # SUM-G3126 and fitting - part # SUM-G1710 (3/8 inch) Put about two wraps of teflon tape on the gauge's threads and screw it into the gauge fitting. Make sure the tape doesn't extend below the threads. Hand tight will not be enough so use a large wrench or vise to hold the fitting and a small wrench to screw in the gauge.

The fuel line you want to tap in to is the fuel line closest to the oil dip stick (see diagram above). It is a rubber hose that connects to a metal pipe near the engine. Before you start cutting the hose you have to release the fuel pressure so see the Fuel Pressure Release How-To: http://www.geocities.com/MotorCity/Speedway/8537/release_fuel.htm. Now you can cut the fuel line but use a rag to keep fuel from spraying on you and have two 3/8 inch plugs ready to stop the fuel flow (it will dribble out continuously unless you plug the hoses). The fuel lines have an insulation tube wrapped around them which makes them look larger than 3/8 inch. I had to remove the insulating tube from the fuel line so I could get the clamps on the hose. The insulation tube will come right off after you cut the fuel line. After installing the gauge and tightening the clamps you need to prime the fuel system. See the Fuel Pressure Release How-To (above) for instructions. Make sure there isn't any pooled fuel anywhere before you start the engine. Take a good look for fuel leaks.

Normal idle fuel pressure is 28-32 psi. Pressure with the F/P (fuel pump) and GND (ground) diagnosis terminals jumped should be 36-38 psi. If your gauge goes high enough, you can check maximum fuel pressure (71-107 psi) by plugging the fuel line on the engine side of the fuel gauge. This keeps fuel from going to the fuel pressure regulator which bleeds off excess pressure by returning fuel to the gas tank.

NOTE: DO NOT ROUTE A FUEL LINE INTO THE COCKPIT! TO PLACE A FUEL GAUGE IN THE COCKPIT YOU MUST USE AN ISOLATOR OR AN ELECTRICAL GAUGE WITH A SEPARATE PRESSURE SENDER.

If you are installing an electric pressure gauge you can install the pressure sender in the same place in the same way and then route the output wire through the firewall to the gauge.

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