So, you either don’t presently have a fuel pressure gauge on your engine, or the one you have is now giving you fits.
Ok, no problem, source a new one & beautify your engine compartment!
Make sure you get a liquid filled gauge, as the vibrations from the motor tend to knock the gauges out of whack after awhile from your constant foot to the floor turbo blasts going down the road. (hey, we’re not judging… just the facts).
Sure, these fuel pressure gauges cost a bit more, but isn’t the extra expense worth the reliability & longevity? We think so, and I believe most owners would agree. After all, you want nice & useful goodies on your G-body, don’t you?
1. disconnect the battery for safety.
2. relieve the pressure out of the fuel rail by utilizing the schrader valve, etc.
Place a rag under the outlet & surrounding areas to catch all the excess gas that will be coming out. (or use a catch can of some kind, and also the rag for extra insurance).
3. If your fuel rail on your turbo buick does not have an adapter end with outlets like shown in the picture below, you will need to acquire one.
4. If you already have one, great. If not, get one & install it (use teflon tape).
Once you attach this fitting to the rail, you can then use either of the remaining 2 ends of this fitting for your new fuel gauge location.
One end is open & has a schrader valve in it (usually the one that faces forward), the other end (the one facing up) has a cap on it (& there’s probably another valve in there too).
Choose which port you want to use, either location is fine.
It is a personal preference depending on what other attachments (if any) you have to go on the rail.
If you use the one that faces up, you will be able to read the gauge as you adjust the fuel pressure.
If you use the front-facing port, you can only read the gauge when you are looking at it from the front of the car (unless you attach a 90 degree fitting on this port which points the gauge facing up).
The decision was made to use the port facing up on this particular Buick GN, since there are other FP sensors & stuff that are being monitored too, from the fuel rail.
If you ONLY have the fuel gauge to attach to this new fitting, be sure to put the schrader valve back in the end that the gauge is NOT going onto (this could come in handy later on for draining the fuel rail / gas tank, etc.).
The end that the gauge is to be attached to should be left open (so the gas can hit the fuel gauge).
5. since most fuel gauges have a 1/8″ NPT male threaded end on them, you will need an adapter that has female threads on both ends to attach the gauge to the rail. (like the red one shown in this picture).
6. apply teflon tape or paste to the male threads.
7. tighten the adapter onto the rail.
(you put this on first because the adapters are usually made out of aluminum, which crushes easy! If you were to put this adapter onto the gauge first, the wrench end of the adapter has no support inside, thus, you can crush it when you tighten it onto the gauge! look at the pic above & just imagine doing that!)
8. tighten the fuel pressure gauge into the adapter.
You may have to fiddle with the tightening to get the gauge to be able to be read facing straight up.
9. turn the Buick Regal car key forward but with the V6 engine off & check for leaks. Fix if needed.
10. start the 3.8 liter engine & again check for leaks. Fix if needed.
11. readjust the fuel pressure to the proper specs for your buick v6 engine.
(you may find out that you need to correct it, since you now have an accurate FP gauge!)
12. take your TR out for a spin & make sure all is well!
(the test drive is your reward for doing a good job!)
If you need a new rail mounted fuel pressure gauge, you can acquire one like shown in the above pictures (they have a silver colored one too) from Full Throttle’s website:
fuel pressure gauge
P.S. they have adapters as well.