I want to install an inline fuel pressure gauge in my 1.8L to monitor things while I diagnose some issues. Where is the proper place to do this for monitoring fuel pressure?
Diagram from PP:
http://www.pelicanparts.com/914/technical_...4_18FI_diag.htm

Check your fuel rail on the left side. Many have a tap you can use. Otherwise, splice one in anywhere before the pressure regulator.

I just tapped the drivers side diagnostic port on the fuel rail and ran the hose by the air box to the Fuel pressure gauge. Works great.

It was not easy to find something that screwed into the factory rail between cylinders, so I went to Harbor Freight and bought a fuel pressure tester.... Harbor Freight Link on sale for $20.

In the engine bay, I cut my new fuel line just past the hard line coming from the pump. I spliced in the silver union in the center of the picture. Did not use the hose clamps in the picture, used the German type. Then screwed the gauge into the new rail. Registers about 40. Alittle jumpy at idle, but very still at 3k rev.

Click to view attachment

I found my connectors on Amazon but I did have to look awhile. I disconnected my cold start valve (left side) and used that hose to barb that screwed into my gauge. So far so good.

You don't screw anything onto the fuel rail, you just slip another piece of hose over and put a hose clamp on it. Just like the other connections on the stock fuel rail.

--DD

Thanks all. I don't intend to try to screw into injector rail, just put it inline somewhere in the 7mm hose. I just needed to know where, and now I know.
FYI, JEGS has the gauges for $20, and also the fittings to put inline with hose. You can go with 0-60psi or 0-100psi in a multitude of colors/finishes.
(On the topic of JEGS, I've had great experiences ordering from them. Even with standard shipping, the part sometimes shows up the next day!)

http://www.jegs.com/p/JEGS-Performance-Pro...763500/10002/-1

I cut the fuel line going to the cold start injector and put in a T with one port having FPT threads and mounted a VDO gauge right to it.

I can adjust my fuel pressure at the regulator while looking at the gauge and it also instantly solved the mystery when my low fuel light quit working and I ran out of gas....

Let us know what pressures you see when you get it hooked up.

L-Jet FPR are not adjustable, it uses vacuum.

I picked up a adjustable with vacuum but havent had time to install it.

The Turbo import cars use them.

I have that same fuel pressure gauge tool kit. The difference with the JEGS gauge is that it is fluid-filled, which keeps the needle from bouncing around.

Here are some pictures of how I routed mine.