1992 MB 190E 2.3 L

I have a 1992 190E that shakes at an idle. When I'm driving
down the road the car is fine. But stopped and idling I can
feel the car shake. Off idle it's OK. The head gasket was
replaced before I got the car. Below is a list of the things
I've checked. Does anyone know what the valve timing is supposed
to be? The exhaust valve closing before TDC seems wrong to me?

Engine mounts: OK

Compression: All 160 psi

Cylinder balance: even

Ignition
spark: OK
wires, cap, rotor & timing
adjust timing: 0 deg
replace plugs: Bosche platinum

Fuel System
fuel sample: OK
cold start valve: OK (line disconnected)
system pressure: 80 psi
lower chamber pressure: 74 psi (raises to 80 on decel)
regulator current: 20 ma @ start up; + or - 1 @ warm idle
temp sensor: 2.200 ohm @ 65 F; 300 ohm @ 170 F
throttle switches: OK
air meter: clean & free
air meter position sensor: OK
vacuum leaks: none
decel switch: OK
inspect injector spray: streams
replace 4 injectors and seals
remove throttle body and clean

EGR system: valve OK; vacuum switch broken
replace EGR thermal vacuum switch

O2 sensor: low steady reading
replace O2 sensor: varies .2v to .8v

Charcoal canister purge valve: OK

Cam timing: intake opens @ 18 deg BTC
exhaust closed @ 4 deg BTC

Thanks Jim