... After assembly of the fuel system, run the fuel pump and depress the air flow sensor plate for a couple of seconds to bleed air out of the fuel distributor. Remove one injector line from the top of the fuel distributor, and while looking into the injector port in the top of the fuel distributor turn the mixture adjustment screw clockwise until the port just starts to fill with fuel then turn the mixture screw 1/2 turn counter clockwise. Reinstall the injector line, start the engine and adjust mixture when it reaches operating temperature. This is the Bosch recommended procedure for initial mixture setting and adjustment.
Question: IS the above correct, as far as what I'll need to do, and question #2, the mixture adjustment screw is the one located in the tower that's protected by some form of tamper proof device. Correct?
I‘m currently actually not posting in other member‘s threads (due to technical forum problems), but during browsing the forum a little this morning I came across this thread and I thought I should make you & other readers aware that following ^these instructions would (particularly in your case !
) be counterproductive. … As I explained in detail in https://www.benzworld.org/forums/w12...uty-cycle.html
, it would wipe out valuable diagnostic information for good … which, particularly with the adjustment tower still in tamper-proof condition, thus the Lambda adjustment screw likely never having been tinkered with, would really be a pity.
In that thread I also said (in post 61) that “adjustments via adjustment tower should be done only in order to readjust a deviated EHA operating range according to EHA current / duty cycle … and only if all potential problems that cause the deviation have been checked and, if necessary, fixed or manufacturing tolerances of replacement parts require it !“
… Maybe it wouldn‘t be a bad idea to print that sentence on adhesive film and stick it somewhere clearly visible in CIS-E car‘s engine bays. …
Anyway, the instructions you posted in post 17 are meant for the K-Jetronic, which your car (1991 560SEL) is not equipped with !
After receiving your (hopefully properly) refurbished & calibrated FD, the first thing I suggest to do in your case is … besides leaving the tamper-proof adjustment tower alone … to reinstall it and reconnect everything including the CSV pipe, except the 8 injector pipes. Make sure that no dirt gets into the FD. Then, with an absorbent rag wrapped around the FD, let the fuel pumps run by connecting them to 12 V (e.g. via jumper wire in the FPR socket terminals 7 & 8) and carefully push the AFM plate down by hand. By doing that you should see fuel rising equally in all 8 injector pipe ports! When the fuel starts to come out of the ports, let go of the AFM plate and stop the fuel pumps. Then reconnect all injector pipes, reinstall the FPR and start the car. It may take a little longer cranking than usual but should be possible … unless (an)other problem(s) prevent(s) that.
(not adjust !
) the duty cycle as described in post 2 of the above-mentioned thread. With the engine idling at operating temperature it should fluctuate (as described in that post !
) around a mean value of (close to) 50%, which should put a smile on your face. … A deviation from that value would indicate that there is still a fuel combustion affecting problem. In that case follow the above-mentioned sticker in the engine bay
and only if
(after that !
) the range of the fluctuating (!
) duty cycle is still not close to 50% with the engine idling at operating temperature, then readjust it as described in that same post.
P.S.: I may not notice new replies to this thread due to the technical forum problems (as described in https://www.benzworld.org/forums/w12...l#post17816294
) … I‘ll offer further detailed assistance in threads when the forum is repaired and works properly again.