If you have a 1989 or a 1990 2.6 Liter automantic transmission Mercedes Benz,then there is no PCV. It has already passed emissions.
firing order is1432
Premium. Always.
test
Near the right rear tire
This is a job for a quailified repair specialist not for a DIYer.
call the dealership give the vin #,and they will give you the radio code
Contact a Mercedes dealer. Febi/bilstein Part# 08972 comes in 1 liter bottles. The power steering capacity is 0.6 liters(0.6US qt)for a 1990 190E 2.6
Try Fuel Pump relay behind battery small silver box with a fuse ontop.
Could be a problem with the Overload Relay,maybe one of the fuses need replacement!
You might try 33343. It is the one I use for my 1991 model
The EFI relay is located under the dash on a 1990 Honda. It is on the driver's side, under the steering column.