I have this s420, 1995 I am working on. It is plagued with an intermittent no start problem, she cranks very well, but sometimes cranking, but no start.
There is fuel pressure, but no fuel, and no ignition.
no codes either. sometimes this car will start and run for weeks especially if used every day. let her sit for a few days, problems begin.
a different key does not resolve this problem.
There is a fuel screen in your fuel tank. If the screen becomes covered with debris it will prevent the fuel delivery system from getting fuel to the engine.
I've heard stories of random problems simliar to yours resulting in strange fuel delivery issues as a result of trash in the fuel tank. When the gas "sloshes" around in the tank, it can change the throughput of the fuel screen.
I assume you replaced the fuel filter too? You stated letting the car set is having an adverse effect and causing starting problems keeps me ponder fuel delivery and battery problems.
I would also check the health of the battery. Have the battery tested UNDER LOAD. A “marginal� battery can alter various functions of your car.
All in the fuel supply is replaced, the injectors simply do not operate, there is good fuel pressure.
The battery is new, and voltage supply is really nice.
I did order another key from the dealer.
still need more ideas, think this new key will not resolve the problem..
If you haven't replaced the wiring harness on your S420 1995 M119 engine, it is probable time. The wiring harness is constructed of biodegradable material coving the wires. With the M119's heat and age of the harness, the insulation will become very brittle and crack, leaving the wires exposed. Needless to say, this can cause numerous electrical problems. As a side note, the harness controls the impulse to the fuel injectors. But you said there are no fault codes associated with the starting problem. You can use an inexpensive engine stethoscope to listen to each injector. You should hear a ticking noise if the injectors are working. This however does not indicate the efficiency of the injector spray pattern. But you are not having performance problems once the engine is running so this doesn't indicate an injector problem.
Has there been any work performed on your car before the problem started. I know you mentioned you've had work done on the fuel system. Was this the result of trying to address your current starting problem
I am having the same problem with my 1993 400 SEL. I have replaced the engine wiring harness, fuel filter, fuel pump, mass air sensor, and I still have the problem. It only happens when the car has set for a week without being started. I have kept both outdoors and garaged and had this problem. If i start the car and keep the RPM over 4000 for about three minutes the car won't stall. Any help would be greatly Appreciated.
Well, you say that fuel pressure is OK, but there is no fuel and no ignition.
How have you verified this?
If there is no fuel from injectors (which you say have fuel pressure), and there is no injection, it means that the computers do not provide the required signals, and that it is something in common to the injection computer and ignition control module.
There could be numerous reasons for that. Engine wiring harness could be one thing, power distribution another possible cause, or it could be some input signal to the system.
Some common input signals, I can think of, are crankshaft and camshaft position sensors. They both go to the ignition control module, which again will provide timing signal to the injection computer. Failure in any of these sensors will give the symptoms as described.
In any case, try to get an error code readout. This will probably guide you in the right direction.
Linear Mode
