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Discussion Starter #1
My 1998 E320 wagon turns over but does not start.

It started by quitting while idling. Wait about 10 minutes and it would start again. It seemed to be heat related, when the temp got to about 98 then it would stop.

Sat it quit and now will not start again. (3/4 tank of good gas)

Other threads here have pointed me to CPS & MAP. I replaced the CPS and it had no effect. Unplugged MAP, no effect. Stole a MAP from my son car (2001 E320 Sport) - no effect.

Checked fuel relay - functions.
Checked fuel pump - functions.
Checked for power while starting at fuel pump - dead. 12v is not present when the key is in position II and not present when car is turning over.
Checked all fuses by battery, in front of Driver and in front of passenger.
Replaced fuse 6 by battery.
Even fixed a harness to relay, 12v is not being applied to relay to trigger fuel pump during starting process.

Replaced batteries in key fob & cleaned ignition lens

Only code is P0110 "Pending" Air Temperature Sensor -- This occurred after I unplugged the MAP. I and looked carefully on the intake and I don't see any sensor. (Is it part of MAP?)
 

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'01-E320 & 02-ST2
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So it will not start at all now? Or it still does the same thing, starts, reaches a certain temp, and then dies?

It's also important to describe what you're working on instead of using an acronym, unless you're 100% sure the acronym is correct.

"CPS" --you could mean a crank sensor or a cam sensor. The former is a common cause of what you describe, and you have to replace it with the correct part (there are two and they're not interchangeable). If replaced with an off-brand chinese knockoff it may not function properly. It's also important to check the wires leading to the crank sensor as they can chafe through the insulation and then short.

"MAP" refers to the manifold absolute pressure sensor. This is rarely an issue, but it can be and is usually diagnosed if not through a code, through live data that reflects implausible readings, or of course if it is physically damaged when the belt or idler pulley fails.

The IAT (intake air temp sensor, which is your code 110) is incorporated into the MAF/AMS (mass airflow or air mass sensor) on your car. Unplugging the MAF sensor will usually result in a few codes and it the most sketchy of tests.

Do you have fuel under pressure at the rail when the no-start condition occurs? Have you checked the K40 relay?

Please update with more details and include what mileage is on the car, what maintenance has been deferred and what maintenance has been performed.

Good luck.
 

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1999 E320 AWD, +127k miles
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Question on the crank position sensor(CPS) and a Crank No Start problem.

After searching the stickies, i found some info that indicated a faulty crank position
sensor(CPS) can also cause the engine control module(ECM) to NOT energize the fuel pump so there would be no pressure at the fuel rail.

Is this correct?

I can understand a no ignition/spark condition, but can a faulty cps(crank position sensor) also shut down the fuel pump?

TIA.
 

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Discussion Starter #4
Crank Position Sensor - you are correct.

The question regarding "is the wiring frayed" led me to examine this closer.

I was suprised when I pulled on the plug and it slipped right off the sensor. Upon detailed examination, the sensor that I had gotten was German made but had the plug latches (bumps on the side of sensor) only on one side. The original had it on two sides.

I took it back to the vendor and found that it was indeed the wrong CPS. After chasing down the correct sensor all is working correctly.
 
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