Thanks for all comments.

Just FYI: before checking this valve, I had replaced all injectors with new Bosch. Also replaced injector seals seats and o rings. Also replace all plugs, wires,,cap and rotor.

The spring isn't broken - it was removed and cleansed and in good condition.


At the moment, I believe the problem is the fuel distributor, I believe it has a damaged diaphragm and is pumping out too much fuel at low rims to cyl 1. I had originally thought it was a leaking injector, so I replaced the injectors. The only conclusion I can come to now is a fuel distributor.

Rebuild kit arrives today ($94 on ebay from CIS-jetronic).

I have reason the believe the "sticking" when compressing the. Valve was possibly related to the MB spring compressor having some interference such as against a fuel line. With the springs removed,valve travel and spin weren't that bad.

Initially I had thought that the fuel distributor was less likely to fail rich, but this was based on my reading about distributors with stainless steel diaphragms. This car has a rubberized fabric diaphragm, know to fail often with modern ethanolized fuels.

The new diaphragm (from American Precision) is claimed to be resistant to ethanol. Here's hoping.!