what gauge are you getting? i'm using a 0-100psi Marshall Guage that is oil filled.

my exact plan is drilling and threading the head of the banjo bolt on the fuel rail and then welding on the adapter to it. that way i won't worry about leaks. the rest after that is a 1/8" to -3AN adapter with a 48" line to another -3AN to 1/8" adapter to the guage. simple and effective IMO.

 

you don't have to chop up a factory fuel rail for this.

 

Not in the cabin, right?

 

Well depending if I go w/ the fuel rail or off the banjo it will either be mounted somewhere around the firewall area..yet to be exactly determined. But will be visible when adjusting the FPR.

 

<img src="http://www.marshallinstruments.com/images/products/MNB.jpg">
this is it, its just that mine is 0-100psi. I've got a local guy who can test accuracy of the gauge. hmmmm, maybe i'll run it by him.

 

fuel actually needs to be warm, but not HOT

 

<center><img src="http://pictureposter.audiworld.com/87401/image002.jpg"></center><p>Ok, here is a picture Cody.
It was very sunny and I was too lazy to move the car so the pic is not the best, sorry

Mark

 

Hope Jerry doesnt mind..but for the archives..here is his write-up that he graciously provide me:

Audi 93 S4 Fuel Pressure Gauge Install, 01-05 by Jerry Scott, revised 04-05

Since this car was having a starting problem, when it sat overnight at Vail, when the air temperature was 10º F. or colder, I decided to install a fuel pressure gauge in the fuel rail to see if I could learn whether the car had fuel pressure while attempting the start. I had learned on the internet that when either the FPR (fuel pressure regulator) in the fuel rail or the check valve in the fuel pump (in the tank) failed, starting could be difficult due to low fuel pressure. When the pressure in the fuel rail is finally pumped to 55 lb./in², the car will start, if the battery has not run down by this time.

To install the 1.5 in. Autometer, model 2177 gauge, first the fuel rail must be removed. To do this, first remove the plastic cover held on with two Allen head bolts. Then remove the two Allen head bolts holding the rail in place. Remove the banjo bolt at the front of the rail, where the fuel input tube is attached. Catch with a rag the fuel that will spill out of the fitting. Next remove the fuel connection at the bottom of the FPR and at the back of the rail, where the return fuel line is attached. Remove the five clips that hold the rail to the injectors. These just slide off sideways. Be careful not to drop them. With a crow bar padded against the valve cover, pry the fuel rail upward off the o-rings of the injectors.

Now that the fuel rail is removed, place it in a drill press vice and drill a 21/64 dia. hole in the center of the flat area opposite the hole for the banjo fitting. Then put a 1/8-27 pipe thread tap into the drill press chuck, lower it onto the rail and turn it by hand to start it into the drilled hole. When you reach a point where you can no longer turn the tap by hand, release the chuck and attach a tap handle to the tap. Make ¼ turns then reverse followed by ½ forward turns. Repeat this until you have the depth that is needed. Use oil on the threads to lubricate the cutting. After each full turn, back out the tap, clean off the shavings, and check the depth by inserting the gauge. The gauge should go in about half of the threaded length of the gauge. Thoroughly wash out the rail with soap and water to remove the oil and shavings after the tapping operation is complete. Install the gage into the rail with two full turns of Teflon tape, by using only hand torque. Make sure that the Teflon tape does not get into the rail after installation. Using a hand file or Dremel tool remove plastic from the rail cover, so that it will fit around the gauge. Place a very small amount of dish soap on the fuel injector o-rings and press the fuel rail in place. I used a rubber mallet against the rail, while striking it with a plastic hammer. Replace the five clips and make sure that they engage properly with the rail and the slits on the side of the clips. Install the banjo fitting and the FPR line fitting as they were removed. Be very careful to not over-torque the banjo fitting as it is tapped into aluminum.

<img src="http://pictureposter.audiworld.com/9882/fuelgauge.jpg">