7693A ALS injecting excess volume

[LALman]

My 7693A ALS injector has recently started occasionally injecting about 50% larger volume that it should. We are injecting 5uL from the standard 10uL syringe. Several times now, we are seeing apparent injection of ~7.5uL. e.g. a 1000 ppb standard is suddenly 1500 ppb and the surrogate is correspondingly higher at 150%. We can see that the solvent peak is distintively fatter.

If this is normal wear and tear is there a kit for servicing the detent system that controls the syringe needle pull out?

[lmh]

Have you caught it in the act and seen it do this? It would be quite a large error to happen mechanically. Is it possible that there is something unreliable going on in the inlet and it's a different efficiency of vaporisation/split flow or something???