Poking about today, I find that one of the injectors on my wagon is
apparently the root cause of my once-in-a-while
running-on-three-cylinders symptom. If I wiggle that injector while the
engine is running, the engine goes erratic. Wiggling the others causes
no symptom.

I did recently let the car run almost dry and I'm wondering if some
floating crud got in the fuel lines and made it into this injector.
Would like to take out that injector and clean it. How do I remove the
fuel rail, though? Feels like the injectors are held in just by O-rings
and should just pull out - but then there's the minor detail of
relieving fuel pressure. There's a screw-on plastic cap at the inlet
end of the fuel rail; is there a valve under that or will unscrewing it
squirt gas everywhere?

tia..