'03 270CLK - CDI Pump re-sealed, been working....!

[Highmileage]

Guys, my venerable 248K mile 270CLK was getting very difficult to start. Diagnosed a leaky CDI pump and re-sealed it. It took ages to get the car to run (several re-charges of the battery). Once it did run it then started and ran ok but was erratic, sometimes starting straight away, sometimes taking an age. It also would stop dead if I gave it full power, which was a real problem. I read on here that it was possible to cross connect the two plastic pipes which go to the left side of the pump (viewed from the front). I had been wondering if this was the erratic problem. So, as the weather was nice I decided to check and sure enough, from the various diagrams online, it seemed they were wrong. I changed them over today to what the pictures show - rearmost pipe to the common rail, front pipe (the short one) goes into the connector mounted above the CDI pump (it also has a tee off it which goes back to the filter (?) RHS rear of engine. Now I have the same problem, it simply won't start! There don't seem to be any bubbles in the pipes now. Nothing else has been changed so it was running yesterday, I've swapped the pipes over, that's all. Any ideas please?

 

[mersum1es]

Frontmost goes to rail... it won't start at all if they are wrong

 

[Highmileage]

Thanks. At least it's a quick job!

 

[Highmileage]

Afternoon guys... again! So here we are a few months down the road. Pump overhauled and motor running. Still cuts out dead under harsh acceleration. Then starting problems have reared their heads again and so further investigation showed that the two pipes going into the pump were leaking. I ordered new o rings and seals from Merc and fitted them. No more leaks but starting problem persists. This is basically time dependent; if the car has only been stopped for 30 minutes or less, then it takes two or three goes. Overnight and it can be seven or eight and even reduced cranking due to a punished (new) battery.

Did a leakdown test and number 1 injector is v bad, number 5 is leaking back slightly. I've just ordered 2 recon injectors (due next week) so that's next.

Any other suggestions welcome, thanks!

 

[mersum1es]

I believe new injectors will cure that...

 

[Highmileage]

Thanks, fingers crossed; it's driving me mad!