Hi All
I've built a bottle jack pop tester that seems to be working OK.

I have five injectors pulled from the junk yard the five from my '85 300td. Without taking them apart they tested from 1650 psi to 1950 psi. I have six that test at 1900 psi. - but two of those have a less than perfect spray pattern.

I disassembled & cleaned the five from the junk yard. Two of those developed a long single stream from the tip at lower pressure and then pop as usual at higher pressure. What did I do wrong to develop this single stream?

I notice that when I pump the tester fast - I get repeated pops at lower guage pressure. But when I pump slowly I get the pop pressures reported above. The rapid pop may not really be a lower pressure but just that guage doesn't reach the slow pop pressure. Any thoughts on this?

If I end up with five injectors that pop at 1900 psi and a good spray pattern - is that good enough even though I'll be a 131 bar instead of the 135 bar recomended? Or should I try to get them all to 135 bar with shim changes?

The hole at the end spray needle is really tiny and I have nothing small enough to insert and check if they are open. I read somewhere here about using music wire for this. Is that correct and if so - wheere do you buy it? Or - other suggestions?

What about the other holes and passageways - do they also need to be cleaned?

I've read about using Untrasonic cleaning - is that necessary for a good job?

So far I'm soaking the parts in carberator cleaner and then spraying them off with brake cleaner. Is there something better to use?

Of couse it would be easier to just send them off to be rebuilt - but for me the fun of owning my Mercedes is the learning experience. So all help & advice is welcome & appreciated.

Joseph