Hello everyone

Just curious if anyone was ever successful in mounting a fuel pressure gauge w/fitting onto the shrader valve(relief valve-test port) found on top of the fuel block on the v6 2.8 fieros?
Thanks
Dave M.

You can buy a fuel pressure gauge from Summit Racing that will screw right onto the schrader valve at the fuel rail. You can check the pressure (which is a good idea) but I don't recommend that you keep it permanently installed. If it comes loose fuel will spray all over the engine and cause a fire. My FP gauge is permanently installed on the dash but the sensor is installed on a T block in the braided SS lines.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Thanks for posting Dennis : D

Would it not be possible to use some threadlocker glue when screwing on the fuel pressure gauge to the Shrader valve in order to keep it from unloosening itself?

Any idea what size the shrader valve is ex: #3AN or #4AN, etc..??

Lastly, I've been reading that the shrader valve on the fuel rail should have a cap over it? and that the valve needle just like a tire valve one, sometimes comes loose?


D

Yes it should have a cap on it.

I have never had a tire schreader valve or fuel pressure schreader valve come loose.

The cap is to keep dirt out of the connection.

You could always thread a nut down the valve threads (outside) and then after installing the valve, back the nut up to the valve tightly to lock it from turning.

Call me cheap, but the shrader valve itself unscews from the fuel line block.
Take the block off, remove the shrader valve and then drill/tap the shrader valve hole for NPT 1/8" which is the common size for most off the shelf fuel pressure gauges.

Put a fuel pressure gauge from the Fiero Store (IIRC)on my Formula. Didn't like the gauge but did like the fuel rail fitting it came with. Used that schraeder valve fitting with an Autometer #3663 electric fuel pressure gauge. The old ones needed a separate amplfier to run the gauge. The new ones don't.
Makes a very nice permanent instl. The sender at the fuel rail is very small and light--won't give you any problems.
The only downside is running the electrical wires and the expense.

Those fuel pressure gauges are a great diagnostic tool. (Just found my leaky injector with it.) You can quickly tell if you have a fuel pump problem, fuse is blown, fuel regulator issues, or like I mentioned a fuel injector problem. They are a must. On my 2.8 I just cut the fuel line and put a T in there. It was a simple install.

Here's my setup as described.
It's the gold and blue widget above the rad cap.

Be careful of the liquid filled gauge from Summit. It has a rubber plug in the side where the liquid (oil) is put in and when it gets hot it gets soft and can come out.

I like Fieroguru's idea of:
unscrewing the shrader valve off the fuel line block, and taking the block off, then drilling/tapping the shrader valve hole for NPT 1/8"

This would eliminate any possibility of fuel leaks caused by using multiple fittings, etc...

Heck, If I could just screw a standard 1.5" liquid filled 0-100psi fuel pressure gauge with straight 1/8"NPT down onto the fuel block without having to use any other fittings, that would be awesome.

However, in looking at past Fuel Press.Gauge posts on Pennocks, looks like everyone had to use (1) 90deg #4an fitting to bring the gauge away from hitting the intake manifold.

Dave M

I think it's easier to just tap into the line for cold start as below and then put the gauge where you want it.