1997 E300d Intermttent No-start
 

NEWBIE NEEDS HELP! I OWN A 1997 MERCEDES E300D AND THE CAR RUNS LIKE A DREAM FOR WEEKS ON END, AND THEN DOES NOT WANT TO START. RECENTLY I HAD MY INJECTION PUMP SERVICED DUE TO LEAKING AT O-RINGS ON TOP OF PUMP. THE FUEL SHOP THEN TESTED THE PUMP AND SAID IT TO BE FINE. ALSO REPLACED GLOW PLUGS AT THE SAME TIME. GLOW PLUG LIGHT CYCLES NORMALLY. I DID NOT NOTICE ANY OF THE RED AND GREEN "FLASHING" LIGHT UNDER MY REAR-VIEW MIRROR. SPIN ON FUEL FILTER IS NEW. THIS PROBLEM OCCURS REGARDLESS OF WEATHER CONDITIONS BUT ONLY SEEMS TO HAPPEN WHEN THE TANK IS BELOW 1/3 FULL. ANY HELP WOULD BE GREATLY APPRECIATED AS THIS IS MY WIFE'S DAILY DRIVER. THANKS IN ADVANCE.:confused:

K40 relay maybe.

Perhaps the fuel strainer (in the tank) is clogged.

k 40 location
 

i have heard of the k 40 relay being a possible culprit. where is it located and what does it look like.

Air leakage into fuel lines is the most common cause of hard starting/hiccuping of the 606 engines-assuming the glow plug system is OK. More common in situations with low fuel in tank also. Has been covered in many old threads and can be researched using the "Search" mode. The rubber O-ring at the top of the prefilter is maybe the number one source of air intake because the new prefilters don't come with a new O-ring, so the old one gets recycled beyond its ability to function.