Pump won't deliver pressure

A problem developed recently. The new jet pump seems to work fine when delivering water to the household fixtures; taps, toilet, shower, washer, etc. But when I run the garden hose the pressure quickly drops to zero. The pump cuts in at about 25 psi and continues to run while the pressure drops. Turn the hose off and pressure comes back up to 40 psi in a minute or two. No evidence of sucking air and I haven't been losing prime. It's a shallow well setup. 55' deep well, water is about 20' from the surface. The pressure tank is about 3 years old and is pressurized to 2 psi below cut in. Could this be a problem with the foot valve not opening fully or possibly the pressure tank? Suggestions appreciated.

It is a problem with the wells capability to keep up with demand. Your using around 2.5 gpm in a shower and your garden hose could be using upwards to 10 gpm depending on it's length and diameter. The tank is only going to take the water the pump gives it and the pump is only capable of pulling the water the well gives it. A 20' water level is only 5' from being the max a shallow well jet pump can lift, so your on the edge there too.

bob...

Problem resolved

Thanks for the reply. I agree with your comments and maybe next summer I'll dig up the intake lines and switch to deep well. The well is over 100' from the house and the line runs under a deck so it's not a small project.

However, the cause of the problem was a misadjusted control valve on the new pump. And my inexperience, and misreading the set-up instructions for the pump. It turns out that a shallow well set-up doesn't need a control valve, and if there is one it should be adjusted to full open. The old pump didn't have a control valve. I had it fully closed, which limited the drive water through the injector and prevented it from keeping up with the garden hose. It works fine now, delivers water to the garden hose at 30 psi.