Just this week I was chasing a vacuum leak on my BMW X3 and decided to check fuel pressure. Cobbled a connection together on my pressure gauge using a barbed connection on the rubber line. No hose clamps..... in about 10 seconds the 50 psi gasoline erupted like a geyser shooting straight up to the open hood. Made a real quick move to shut off the ignition and luckily no fire! Stupid me. Didn't even have the extinguisher at hand. Should have known better. At least the PSI was good