hussman

Hi Guys,
I have a 1998 E240 W210. The engine keeps cutting out. I cant figure out why and need some help to trouble shoot.

So far, I have replaced the Fuel Pump and Fuel Filter, got a new battery, and have confirmed that the alternator is working, by taking the alternator out of the car and to an auto electrician and getting it tested.

Back story, I was driving along one day, stopped at the lights, foot on the brake, engine cut out. Turned ignition off then back on, It started up straight away, didnt think anything of it. Later that day, same thing happened at the lights, but wouldnt start again. Had to call the RAA out (road side assist). He tested the alternator and electrics first. Then went to the fuel pump, tapped it, started working. Said it was faulty fuel pump. Hence why I replaced it.

When I replaced the Fuel pump, the car started about a dozen times, I drove around the block. All Seemed fine. Later that day the car wouldnt start. Turns out my battery had nearly died. The battery was over 7 years old. So I replaced the battery and at the same time had the alternator tested.

After refitting the battery, the car seemed to work fine. Started up a dozen times. Drove down the street. Seemed good. Took it down the main road, coming to a stop at the traffic lights, the car died.

Any ideas what it could be?

bbirdwell

You've caught the obvious failure points, now replace the CPS (Crankshaft Position Sensor) with a quality part (i.e. not the cheapest one at your local auto parts store). After that, could be a camshaft position sensor if your car has one. If it keeps recurring, you'll need to verify the integrity of the electrical circuit to the fuel pump as there could be an intermittent connection; fasten a fuel pressure gauge to the valve on the fuel rail and if the car dies, check to see if you have fuel pressure or not (or even tape the gauge to the windshield so you can watch it real time).

If you place it on a DAS, a 3-minute quick test will reveal most failed components.

hussman

Thank you, I will replace the CPS asap. I have noticed that when I turn the throttle from the engine bay, I can hear a vacuum leak coming from the rear of the engine. It only happens when accelerating with the throttle body. (Obviously can't hear it from inside the cabin).

So last night went to pick up the car after it sat for 8 hours. It started up straight away, I drove it home instantly. (3 minute drive). No cut out. I suspect its got something to do when the engine warms up and the rev's drop back to idle speed, and only when I seem to be driving. As I did let the car idle for 10-15 mins and it had no issues. Hence why I thought I fixed the problem earlier. All speculation at this point.

Anyways, I will replace the CPS (crank shaft position sensor), locate the vacuum leak on the rear of the engine, give it a good old clean up, and go from there.

Will keep you posted.

hussman

Hi guys,

Thought id give an update. The problem was the crank position sensor.

After replacing the CPS. I went for a 15 min drive. No issues.

Just today went for a much longer drive down the highway. Easily in excess of 30mins. No issues what so ever.

After replacing the CPS and giving my breather covers the good clean that they needed (all holes were blocked) my car seems to be driving better.

So if you have any of my above issues. There is a good chance that the CPS is the issue.

hussman

Well its been a few weeks since replacing the CPS and cleaning the breather covers, can safely say that the car runs really good.

bbirdwell

Thanks for the update.