M113, Starting, stalling problem. 99 E55

[ANDYE50AMG]

Car is 1999 E55 AMG 95000miles Tucson, AZ

My E55 has ran perfect for the last couple of months, but last Tuesday I went to the DMV to get her some plates and when i came out to start her up she fired right up then died instantly, I thought I didnt hold the key long enough or something. Wednesday She did the same thing, and then I knew it wasnt just a fluke here is a real problem. It would always start the second time, so I wasnt to worried then as I drove for a bit the same day right after the problem occured again. I was doing about 45mph and the car just shut down, I had to pull off to the side and restart her. After 3 attempts, it finally started again, then I didnt have a problem the rest of the day. I caled my local mechanic, who I was recomended by many people. The place is Benztek on Speedway. Mark seemed very knowledgeable and he has been in business a long time.

Saturday the car was hooked up to the emissions testing machine through OBDII port and passed with "no malthfunctions. I took the car in monday this week, and he read the codes. There was no Check Engine light or anything that was out of the norm. The only code he got was low battery, but he said those were "old codes". He recommended to change the Crakshaft Position Sensor, and that 9 times out of 10 was the culprit. He also briefly mentioned that the car may be stalling/not starting from a fuel pump problem or a clogged fuel filter. But he said he was only going to do the CPS and that would likely fix it.

The major problem is it never acted up for the 4 days he had it, NEVER ONCE I told him to let it sit in the hot sun for a day then start it in the heat of that day, but it fired right up.

So basically I have a car that runs great and has tons of power, he even said it runs like its new. And it never acts up at the mechanic, he must have started it 40 times throughout the day and it fired up everytime.

The bill was 320 dollars and I was confident it was fixed. Well, today after the car sat in the blazing sun for 8 hours I started it and it died instantly.

NEW MAF, NEW CPS, Wont do it for the mechanic.

What other things can cause this problem? One thing that I have noticed the 10 times it has done it is that the ambient outside temp reads 110 or above at first. The real air temp is about 98-102.

Any help is appreciated
Andy