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2001 ML320
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Discussion Starter #1
I've enjoyed being a lurker in these forums for a while now, but a recent issue has cropped up on my wife's 2001 ML320 that I need input on.

A few times over the past year, the truck wouldn't start up; it would turn over but not catch/start. Waiting at least 15 minutes and trying again would do the trick - the engine would fire right up. The check engine light never comes on, and on previous occasions the dealer has not been able to find the problem; I assume that no error codes were reported by the engine.

This afternoon, after filling up at the gas station, the truck refused to start again. However, this time the engine would turn over and almost catch (causing the truck to shake slightly), but then fail. A friendly mechanic driving by looked at it and thought that the mass air sensor needed to be replaced, noting that he's seen that particular problem often. After trying for an hour and a half, we called AAA for a tow - only to have the truck start fine once the tow truck arrived [:p].

From what I've read in these forums, it seems like the crankshaft position sensor is the culprit; if so, I'll be ordering one and attempting it myself. However, the mechanic's advice about the mass air sensor makes me wonder - does the mass air sensor only need to be suspected if the check engine light is on? Is there any other things I can try to help narrow down and troubleshoot the issue?

Thanks in advance for any input you all can provide.
 

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Coupe/Convertible Forums Moderator
CURRENT: 2011 SL550, 2011 C300 FORMER: ML350, CLK550 Cabriolet, C240, ML320, 300TD
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19,235 Posts
I doubt it's the fuel pump as the MY2001 shoudl have the redesigned model. It coudl be the crank position sensor.
 

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2000 ML430
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657 Posts
gronk - 4/27/2005 9:46 PM

I've enjoyed being a lurker in these forums for a while now, but a recent issue has cropped up on my wife's 2001 ML320 that I need input on.

A few times over the past year, the truck wouldn't start up; it would turn over but not catch/start. Waiting at least 15 minutes and trying again would do the trick - the engine would fire right up. The check engine light never comes on, and on previous occasions the dealer has not been able to find the problem; I assume that no error codes were reported by the engine.

This afternoon, after filling up at the gas station, the truck refused to start again. However, this time the engine would turn over and almost catch (causing the truck to shake slightly), but then fail. A friendly mechanic driving by looked at it and thought that the mass air sensor needed to be replaced, noting that he's seen that particular problem often. After trying for an hour and a half, we called AAA for a tow - only to have the truck start fine once the tow truck arrived [:p].

From what I've read in these forums, it seems like the crankshaft position sensor is the culprit; if so, I'll be ordering one and attempting it myself. However, the mechanic's advice about the mass air sensor makes me wonder - does the mass air sensor only need to be suspected if the check engine light is on? Is there any other things I can try to help narrow down and troubleshoot the issue?

Thanks in advance for any input you all can provide.
Sound like the fuel pump. Have the dealer check it.
 

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2001 ML320
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5 Posts
Discussion Starter #6
Hmm...I've done some forum searching, and it seems like the fuel pump would normally be the prime suspect - except as rudeney pointed out, the fuel pump seems to have been redesigned in MY2001 to fix this issue.

I think my best bet is to try replacing the CPS, since it's also the cheapest possible fix. If the problem rears its head again, then maybe an expensive trip to the dealer for fuel pump replacement may be in order.

Thanks all for your advice - I will report on any progress on this issue, so maybe someone else with this problem might find it useful.
 

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Black 2005 ML 500
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1,662 Posts
Nope... I had have 3 fuel pumps on my 2001, the first one was failing since my ML was brand new (100 miles) and it was a nightmare to pinpoint the problem by the dealer.

Finally, the dealer decided to install a new fuel pump and the problem were gone.

My problems were not at startup, though, a lot of the people who had their fuel pumps go bad, had their vehicles fail to start when the fuel pump overheated and had to wait until it cooled down. My problems were hesitation, turning the vehicle off during initial forward or reverse, etc..

I haven't hear people having their vehicle not starting because of the MAF, which is just an air sensor that provides feedback for efficient combustion and tuning.

I will start with the crank shaft sensor because of the cheap price and ease of installation.
 

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2004 CLK500 * 2000 ML320 * Honda RVF400RR
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37 Posts
My 99 ML seems to have the same problem. How much does the CPS Cost and where is it located ?

Tks
 

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CPS

Had several "stall outs" in my ML. Mechanic replaced the Crankshaft Position Sensor (300 including part, labor, tax 7.5%). So far, car is running normal. Although, I am still experiencing rough idles in the morning. Grr.
 

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1999 ml320
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3 Posts
CHECK THIS OUT---my wife has been stuck at the store 3 x in the last 2 wks. calls me i arive and the ml320 starts like it is afraid i will kick its headlights out. wife is going nuts. me too. I replaced the battery, no help, I checked all the conections on the ground terminals. the truck simply tic, tic, tic,tic. Sounds like the starter but in 20 minutes (about the time it takes me to get to the car) she starts up fine.
 

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2002 ML55 AMG, 2005 Chrysler Crossfire Coupe Limited, 1999 C280
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4,714 Posts
CHECK THIS OUT---my wife has been stuck at the store 3 x in the last 2 wks. calls me i arive and the ml320 starts like it is afraid i will kick its headlights out. wife is going nuts. me too. I replaced the battery, no help, I checked all the conections on the ground terminals. the truck simply tic, tic, tic,tic. Sounds like the starter but in 20 minutes (about the time it takes me to get to the car) she starts up fine.
Sounds like classic Crankshaft Position Sensor problems but have the OBDII codes read and post back with the results.
 
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