92 Mercedes 500 SEL won't start sounds like timing may be off and backfires through intake when turning over

SOURCE: 1992 Mercedes-Benz Mercedes Benz 400... Problem:

Hello, What you could have is and ignition problem. I have had to replace many distributor caps (2) and rotor buttons (2) on this model to solve this same problem.
I hope this helps.
CYA, Gtaor241

SOURCE: fuel pump filter for 1992 mercedes benz 500 sel

1992 mercedes fuel pump filter is located on passenger side behind rear drive axle. disconnect battery, raise car and secure it with jack stands, remove rear tire, you will black plastic shield that protects fuelpump and filter

SOURCE: 1984 Mercedes-Benz 500 SEL

In the driver's side trunk along the wheel well and behind the wheel well cover you will find the sunroof motor. There is a plastic knob that can be turned to close/open the roof manually. The socket tool is part of the original toolkit that came with the car, but otherwise, you can locate one that will fit. Don't use pliers as the plastic easily breaks. Meanwhile, have you looked at the fuse or toggled the switch hard to work? If the motor works, but doesn't move there is an adjutment on the motor's clutch that can be tightened. Hope this helps.

SOURCE: my 1992 mercedes 500 sel runs rough once started..

Lots of things to check. From 1993-1995 the US made car compaies use biodegradable insulation on it wire which ages with engine heat and then shorts so check that first. It has an upper harness for engine and lower for charging and starter. Then a real tune up is next coils, cap, rotor and wires. Once youve done that fuel system is next on the list fuel filter and fuel pressure.

SOURCE: 1990 Mercedes Benz 420 SEL computer problem? wont

This could be caused by a faulty Crank position sensor. The computers are expensive for this and not something that commonly fails on these. Have the fuel pumpchecked for operation and pressure. Check for spark at the plugs. Then we can procede further if you would like.