1997 E320 with 122K

Problem just started the other day. After the car sits overnight, the next day it has a hard time starting. It would take about 3 to 4 long cranking to start the car. No check engine lights after the car starts. Once it starts and run, there is no problem starting it up if I shut it down. Once it starts, the car runs great. Right now, it only happens when the car is left over night.

Any suggestions before I take the car in for service?

 

My first guess would be the fuel filter. which I believe does have the fuel pressure regulator built into it. When the pressure regulator goes bad, it can cause an extended crank time, most of the older Benzes had this style fuel filter.
You would check this with a fuel pressure gauge, and the pressure should stay at 50-60 psi. after shutting down the car. It should hold that pressure so when you crank the engine the next morning there's still fuel pressure there and the engine fires right up. youll probably be due for a new filter anyway, not to expensive.

Of course there could be other issues causing your extended crank.
Good luck.

 

Hey Chassis221,

Well, I got around to replacing my fuel filter and the problem did not go away. From what I can see, the fuel filter looks to be a normal fuel filter. It doesn't appear to have any pressure regulator built in. Maybe the pressure regulator is in the engine bay on this model year?

 

* Bad fuel?

* Failing valve cover seal in the spark plug hole = oil soaked (insulated spark plugs - ruined wires).

* Failing ignition coils = weak spark (note: these units have been superseded three times).

* Failing Crankshaft Position Sensor

* Failing Camshaft Position Sensor

* Fuel pressure regulator failure.

* A failing fuel pump.

whunter@pelicanparts.com


.

 

I have E320 1996, had starting problem, won't crank. Was advised to change the neutral switch whch I couple of months ago. Again I have similar problem which begins after leaving the car for few hours....I am advised that I should wait first for all the lights to turn on on the gage and then crank..it works but sometime lights take a while! Frustrating situation! Any advise!

 

My problem ended up being the crank sensor that was bad. From your descriptions, it sounded like exactly what my car was doing. Overnight was the worst, it would crank for a long time before starting. Once the crank sensor was replaced, it now runs like a champ...

 

Hi
As I have already replaced Nuetral switch, Can you let me know the how much was Crank Sensor replacement cost you ? Regards.Saiyed

 

It ended up costing me about $500, since I decided to go with an OE crank sensor instead of an after market one. The crank was around $300 plus 1 hour labor from my local shop. It is easy to replace with some simple tools, but I don't want to be replacing parts to find the problem.