yellow = conical surface = the DV valve seat and sealing surface.

Without the collar, you depend solely on the return spring to end injection events. This is highly inaccurate and uncontrolled. Like jumping off a roof onto a trampoline instead of using fall protection and a harness.

If you are a machinist, perhaps you could find some high precision springs to replace the 'good enough' Bosch return springs?... I can't really guarantee anything positive.


Personally, I think the high EGTs are a result excess fuel being dumped into the cylinder at an unbalanced rate. Dribbling injectors, elongated events and lots of wasted fuel since the metering of the fuel at progressive rates is not there.

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