Pintle Chatter

Last night I was testing my injectors by doing prowlers patented injector test.

I've come to the conclusion that the metering head is at fault because its very hard to lift the pan and after closing it takes along time(5-6secs) for it to stop the fuel.

However I notice that I wasn't getting the expected high pitched sound from the injectors (Unless its so high I can't hear it).  I am using a set of new injectors from Crazy.

So I thought I'd try the original injectors and they did make the expected noise.

I also noticed that when I did the test with only 1 old and 3 new, the only injector to open was old one.

Anyway I've hopefully sourced a new metering head but should I be concerned about this lack of chatter?

Thanks in advance

sounds to me like the old injectors are morte worn than the new ones, so are opening at a lower pressure?  since you have correctly diagnosed that the metering head is not healty I would not worry about your new injectors for now