Fuel Pressure tester

[srb7f]

Just bought a generic fuel pressure tester at the FLAPS, and now that I get it home, I realize that the fitting on the end of it will not mate up directly to the 914 fuel rail. That fitting looked awfully tiny...is it some type of special fitting that you won't find locally? In other words, should I keep looking for one with the right fitting, or just chop the fitting off and put a hose clamp on there (since I'll never find one with the correct fitting?) Steve

[Dave at Pelican Parts]

I'm not sure what kind of fitting is there, perhaps a Schraeder valve, like on a tire filler stem?

My gauge had an NPT threaded fitting on it. I screwed a barbed fitting onto that, and clamped a fuel hose onto that. Then I clamped the other end of the hose onto a part of the fuel rail--I used the fitting that goes to the cold-start valve, as that isn't used that often anyway.

--DD

[srb7f]

That's exactly what's on there. I just didn't know if you would ever find something that would screw directly into the 7mm bolt on the fuel rail. I think it'll just be easiest to chop it take the bolt out, and stick the hose on there for my readings. Steve

[Dave at Pelican Parts]

The inside of the part the bolt screws into is soooooooo small, I doubt you'd find anything reasonable that could go in there.

--DD

[ratwell]

The screw is 4mm with a 7mm head on the L-Jet fuel rail. If you look at the shape of the test port it was designed for a hose.

I believe the universal fuel pressure testing tool sold to mechanics back in the day had an adapter that amounted to a barbed connection and a fuel hose clamp. I say believe because I researched it and it would cost hundreds of dollars to order the items and find out.

JCW sells an L-Jet pressure tester for $27 which comes with a bunch of hoses. I only mention it because it's garbage and the L-Jet part is, you guessed, a barbed connection and a hose clamp. If you have a Honda it also fits the 6mm test port on the fuel filter which makes it a bit of a bargain if you ignore the quality.

I eventually decided that the best tester you can own is one you build yourself. Find a quality made 60psi gauge and get a brass fitting that adapts 5/16" barb to 1/4 FPT or whatever fits your gauge. Use loctite 565 on the threads. You'll need some more fittings if you want to splice in a purge valve so you can disconnect it when the fuel rail is at normal fuel pressure and not spray fuel all over.

There are few really nice 304/316SS gauges in the $30 range which are accurate with safety glass windows that are gasoline proof (unlike lexan or polycarbonate).

[jamcleod]

i bought a pressure gauge at home depot for (?... ) cheap. it was located in the section near the sump pumps. i bought a hose barb that fit the gauge and connected a short section of FI hose. when this was connected at the port referred to above, i could measure the fuel pressure.

[DDS]

I installed a pressure gauge directly on my holley regulator and can now check the fuel pressure at a glance. It has come in handy, and I'm going to do the same on the car I am currently restoring.

Dave