It was on a very warm day back in April that I drove my 2000 MB C280, it ran smooth and well (it has around 116,000 miles and well-maintained). After a few errands I stop to shop at a store for about 1/2 hour, after I came out it won’t start. Just crank but won’t start. Had it tow to my local mechanic, by the time he look at it, it started with no issue, and there was no error code when he plugged in the computer scanner. Mechanic told me it’s either the crankshaft sensor or fuel pump.
The car ran fine since. Then on 6/29, another hot day, it won’t start again after I have driven it for a while and stopped at library for about 15 minutes. Same thing, crank but won’t start. I kept trying every minutes or so, after about 10 minutes it started again.
Both times happened on very warm/hot day. I have spent so much on getting it up and running after 2 years of not driving it (2012 to 2014), not feeling like playing guessing game to replace one thing and turned out to be another. Is it fuel pump or crankshaft sensor?