Reading these post appear to make this appear difficult to do.

This goes back far too many years ago that I care to remember. I purchased an All IN ONE access fitting kit (with a simpler part number, AC-1) that came in a Band-aid type flip top can from a refrigeration supplier.

It has saddle tee fittings, tubing and sweat type Schrader valves with metal caps. No flux and low heat required! It is not a big deal anyways because the joint is so small.

Sealed Unit Parts Co., Inc. made it. Allenwood, New Jersey 08720. This was some time ago but the Phone number on the can is (201) 449-3300. Not so old, at least it has an area code on it. Check this out for a dealer or to see if something like it is still handy.

I unclipped the injectors and popped off the rail then drilled a hole for the fitting. Used a small torch and sweat it straight into the rail. The end job is short and neat. I purged out the rail in case of any metal chips. Put it back on.

I used my refrigeration gage set to see the pressure and then just put a cap on the valve, when I was done.

All I used it for was for rest pressure time out. Now I know what can cause the long crank times. The gage just told me that is was for sure, going down. Still had to think out which one of the three best possibilities was it.

I have used it once, so I would not get all enthralled with making directional flow hoses and valves for no more than you will be using it for diagnoses. I have two more cars that I could have put the setup on but have not so far! IMHO, it is easier to make part changes and checks, looking for classic symptoms, as they can get you just as close. I will say that, knowledge of the pressure can help pinpoint some of the subtle things, if you are a finer hair of a mechanic.

In my case, I am just a plain old, thin hair owner!

Phil