s210 e320CDI hot start issue

[Toby Banks]

Evening All ,
I've had my S210 for a couple of years now , and it has generally been very reliable. In the last few months it has been slower to start , typicaly taking 7-10 seconds of turning over before it fires up. About a month ago , it failed to start ( when hot ) in a car park , which resulted in me calling out the RAC. After a long wait , they arrived , did a few basic checks , turned it over and it fired on the third attempt!! Drove it home and plugged it into my Icarsoft MB1 , which showed the only error was the Mass Air Flow sensor was reading a low voltage. I have now changed that and the fuel filter. I have checked for ' Bubbles in the fuel lines ( non apparant )' and having read all the posts replaced the Cam Position sensor ( easy ! ) and the Crank position sensor ( What an absolute Bar Steward that was- Took nearly two days !! ) this weekend. Guess what - absolutely no difference. Cold starts still slow , but Hot starts are a no no.
The car runs fine once it is going , there are no fuel leaks from anywhere and no codes coming up on the Icarsoft. I took it to my local garage ( not a Merc Expert , but reliable ) and he couldn't seen any codes on his Snap On reader.
My gut feeling is that it is a fuelling issue ( vapourisation perhaps ) . but would Star pick up on these as it uses the 38 pin round plug rather than OBDI. Dont really want to start replacing low / high pressure pumps just on a whim. Is there anybody in South Somerset worth going to ( Dont want to go Ilton ,as didn't have a good experience with them ) or am I better going up to Bristol?

Thanks in anticipation

Toby

 

[alexanderfoti]

Check the rail pressure the next time it does it. It is likely that you have a worn injector leaking off rail pressure, OR a fault in the common rail pump failing to build pressure whilst warm

A Leak off test will identify which of the injectors it is (if it is the injectors)

 

[Toby Banks]

Cheers Alex , Spot on. Checked the Injectors with a leak off test and before it even fired No.2 was throwing diesel everywhere!! Looks like next weeknd is swop the injector time. Hopefully it'll come out easily as there is no sign of ' Black Death '.

Thanks

Again.

Toby

 

[Toby Banks]

Just to close this one out , refurbished injector arrived today and I fitted it. I had read up on all the problems ( Sheared bolts , injector stuck etc etc ) but I had the old one out in under 5 minutes!!The bolt came out easily ( i had soaked it in penetrating oil for the last few days ) and the injector pulled out by hand. No need for the injector slide hammer I'd bought , altho' sods law says that if I hadn't got it , then I wouldn't have got it out!
Cleaned up the seat , greased the new injector with the Febi Ceramic grease , cut a slot in the old bolt to chase out the thread , then put it all back together. Only turned the bolt 90 degrees after torquing it , as the considered opinion is that will do.
Turned the key and it fires up straight away , hot or cold.

Again thanks to Alexanderfoti for his remote diagnosis. Just got sort the bangs and rattles on the suspension now!!

Toby

 

[alexanderfoti]

Just to close this one out , refurbished injector arrived today and I fitted it. I had read up on all the problems ( Sheared bolts , injector stuck etc etc ) but I had the old one out in under 5 minutes!!The bolt came out easily ( i had soaked it in penetrating oil for the last few days ) and the injector pulled out by hand. No need for the injector slide hammer I'd bought , altho' sods law says that if I hadn't got it , then I wouldn't have got it out!
Cleaned up the seat , greased the new injector with the Febi Ceramic grease , cut a slot in the old bolt to chase out the thread , then put it all back together. Only turned the bolt 90 degrees after torquing it , as the considered opinion is that will do.
Turned the key and it fires up straight away , hot or cold.

Again thanks to Alexanderfoti for his remote diagnosis. Just got sort the bangs and rattles on the suspension now!!

Toby

Thanks for coming back and letting us know!

Although, do the second 90 degrees on the bolt, its 2 x 90 and it wont snap (trust me) as long as you torqued it down to 7nm at the beggining. ]