TuanNguyen

Hi..

After a stop for a cup of coffee, the car wont start again. Battery, ignition, is good. gas full.

Prior to this drive. Had replaced valve cover gaskets. I also disconnect the fuel line in order to remove the L/H side cover. Fuel did ran out a liitle bit.
Im thinking there is air in the fuel line after reinstallation and creating vapor lock.

After about an hour cool down with hood up, the car restarts again.

I dont want this to happen again, what you think is the problem and how to fix it?

Thanks! 2003 ML350.

Maj. Dundee

Whenever this scenario occurs it is usually the CKP (Crank Position) Sensor.

TuanNguyen

Took this car out for a drive yesterday. Starts up fine... driving was good.. did not have any problems until we came back out from walmart (about 1hr shopping). The car did NOT start again. It cranks but did not start.
After a few times cranking it (about 15minutes), it finally starts again. This tim witeh engine light comes on. Shut it off.. crank it again... starts with engine light again. Shut it off.... wait.... crank it again and this time starts with no light on.

When i did the valve cover gaskets replacement, i did not remove the Crank Position Sensor (L5). Only Disconnect the fuel line connecting to the fuel rail.

Im thinking the fuel pump is bad.

Just bought this car, sold as is. When i test drove it, it was fine. Didnt know or notice this problem.

Please help....

Maj. Dundee

If you think it is a fuel issue, then you will have to purchase a Fuel Pressure Gauge and when the problem occurs, attach the gauge to the fuel rail and take a reading. It should be around 45-56 psi.

TuanNguyen

Vacumm was a little lose. Pluged it in tight. Havent long test drive it yet. Will update...

mtrevelino

As the Maj said, replace the crankshaft position sensor. It is a common problem!!!!
Mike T.

TuanNguyen

The ckp was the problem that causes the car not to start when the engine is hot. After replacing the ckp sensor, it starts crank after crank while the engine is hot.

To replace ckp:
- use the E8 torx socket. And a small flash light. Small screw driver
- With a cold engine will be alot easier. I had to lay on the engine to get a tippy touch of the bolt with right hand. Very hard to get to the bolt.
- Ckp is locate sticking down into the transmittion case like, on the driver side, on the rear end of the engine.
- The bolt is tough to get to. The bolt is to the right of the sensor. You can break the bolt lose a little bit then finger losen it.
- pull up the ckp.
- disc. The connector.
- clean the hole carefully, there is some debris around it. Dont let it fall into the hole.
- with new ckp, make sure it is clean. Stick it down the hole. It will be quite tight. Push it down all the way. You might have to pull it back out and put it back in to make sure it is all the way down.
- align the holes with the small screw driver.
- (a little antizied on the bolt) and tighten it down.
- plug the connector.

The bolt is pretty tough to get to. If it helpl, you can remove the intake air manifold to have more room.

Good luck!