I have a 1999 ML320 that is hard start from time to time. We can drive it than Park than come back and it spins like its not getting fuel or firing. If you let it sit for a while it starts with no problem.

 

I have a 99 ML320 and that exact thing just happened to me today.
Can anyone help with what the problem could be?

 

It was happened with my car, and i just changed the part name oxygen sensor then it start well

 

I had the same problem with my 2002 Ml320, in my case I changed the fuel filter and problem went a way.

 

HAS IT EVER STALLED? IF IT HAS STALLED THEN I SAY CRANK SENSOR.

 

going to change the crank position sensor next week and will let you know what happens.

 

did you fix the problem? what was it? thanks.

 

In 99% of these cases the crank position sensor is the problem. In oldere model with two locking tabs one on each side of the sensor for electric plug, Mercedes part number
A0031539628 Bosch 0261210141. I believe '98-mid '01.
Newer 01 on sensor with one connector locking tab is A0031532728 Bosch 0261210171. Just make sure you use OEM Bosch otherwise you will have to do it over soon.
you should be able to find them on internet for around $50 or at dealer for about $150.
These are heat sensitive when they get older and that is why when you let the engine cool off for like half hour you are able to start it again with no problem.
Good luck,
Bernard

 

I would like to change the CPS, Does any one have a diagram of the crank position sensor for a ML320

 

mbenz80. thank you. i'll try the cps.