XAS97 – won’t idle, stalls when valves are closed

Questions & AnswersCategory: GeneralXAS97 – won’t idle, stalls when valves are closed
Guest Staff asked 2 months ago

i recently purchased an atlas copco as 97 jd 185 cfm and upon going through the start up procedure everything worked fine.

As directed i opened the valves, cranked the engine until the indicator lights went off, and it runs fine making air; upon closing the valves to connect a hose the machine stalls out almost immediately.

The machine runs fine as long as the valve is opened wide or even just barely cracked open, but if closed all the way it shuts down.

Am i doing something wrong or do you thing there is a problem with the system?

1 Answers
Cas Staff answered 2 months ago

Hi Josh,

Sounds like the engine stalls as soon as pressure builds up.

The compressor is started with open valves so there’s minimal pressure inside the compressor. This allows the engine to start easily.

When you close the valves, pressure will built up. And at one point, the regulating system will do it’s job and it will do two things:

– lower engine speed
– close compressor inlet valve

In your case, we’ll need to do some checks to see what is happening..

Please first check the pressure as indicated on the pressure gauge. Is it correct or is it too high?

It could be too high, which causes the engine to stall.

The fact that the compressor keeps running with the valve open just a little bit, makes me think that your inlet valve might not close completely.

When the inlet valve stays open, the pressure keeps rising. With the valve a little open, the extra pressure is blown off.

The inlet valve could stay open a little because it’s dirty inside. Or, because the control system is not set correctly or is malfunctioning.

Please try to adjust the pressure using the valve on top of the separator vessel.

Try this first and please let me know what you find out.

Good luck!


Guest Staff replied 2 months ago

Adjusted the pressure valve, and it worked. Thank you very much for helping me out, I’m very appreciative that you take the time to help people out. Again, thanks a million!!