W210 E55 fires then dies

[fishmk1]

Recently my car started dying when started then starting on the second or third try. Once running it was fine. Now it's getting worse. No errors on dash except intermittent ABS/BAS/ESP warning which I assume is unrelated. Changed MAF and crank sensor to no avail. Suspicious of earth behind RH headlight, looks crusty and I read somewhere the fuel pump earths here, is this right?

Any ideas please guys?

 

[fishmk1]

Just changed K40 relay which I think does fuel pump. Under ECU cover in engine bay. Fault still happening

 

[fishmk1]

Anyone?

 

[E270 Owner]

The K40 is new?
if not was it checked to make sure it don't have the same fault because its a very common problem.

Open it up and look for cracked solder joints.

 

[horgantrevor]

Best bet it get star test

Have you checked fuel pump itself and have you ever changed the fuel filter on it

 

[c5jganno]

possible fuel pressure problem, or maybe water in fuel rail.

 

[fishmk1]

Not checked fuel pump I might change it later. Not changed filter yet, just started new job so utterly skint which is slightly embarrassing. Pressed the pressure release valve in the fuel rail yesterday and it just dribbled out, not what I was expecting at all.

 

[fishmk1]

If water is getting into the fuel rail, are there any known trouble spots it's likely to be coming from? Or just check everywhere

 

[fishmk1]

K40 is just the black 4 or 5-pin relay, or is it the whole module? Next to the transmission ECU in the engine bay, right?

 

[fishmk1]

Got a new Mann fuel filter so I'm going to give that a try now.

 

[c5jganno]

1st you need to check fuel pressure , if pressure is about 4 bar then that's ok.

 

[fishmk1]

Thanks for replying, I have no gauge but now I know what it should be when I can get my hands on one.

Fitted brand new Mann fuel filter yesterday, also changed cam sensor and changed all 16 spark plugs. It runs better once it's running but still fires then dies from time to time.

 

[Pagz]

My C43 starting doing this multiple times at complete random when I got my new key,the car would fire up fine but die as soon as rpm dropped back from startup,every now and then it would go to crank but stop before the start solinoid got to shift,I changed back to using the old spare key and has never done it since, I assume an issue with the EIS/codes. I have a fault code present on my EIS too.

 

[Anders]

You already replaced the crank and cam position sensor, which would have been my suspects. Is it in any way heat related? My C43 had the same problem and that was the CPS. Maybe a STAR is needed before continuing to throw parts at it - good luck!

 

[fishmk1]

Changed cam sensor, also the whole K40 relay (just changed the 4-pin relay that plugs in the top of it to begin with - duh), all 16 spark plugs for the very recent ones from my old (now sadly dead) car, replaced the fuel filter with a new Mann item (last done 6 years ago according to service history!) checked fuel lines, fuel pump and wiring. MPG is noticeably better and car's a lot more responsive but this fault hasn't gone away. Still fires and dies every now and again. Usually at the filling station in front of people. Off to see Mark at my local specialist Dronsfields in the morning I think and see what he says. If he doesn't know I might try feeding it some sauerkraut or some s**t and then just give up. It's not getting any worse I suppose lol

B*****d car.

 

[Pagz]

Have you check faults with SDS?
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[fishmk1]

Checked and cleared them using a fault code reader at my local garage a few weeks back but made no difference. Going for STAR on Saturday so will let you know if it shows anything else up.

 

[fishmk1]

Looks like it's the EIS. The mechanic at Dronsfields, Mark, ran full diagnostics on it and it had a code I've seen before about DIS communications. He also told me if you start it like a normal car ie. turn and hold the key in the Start position until it fires, it starts every time. I'm perfectly happy doing this for now so I'll wait until it becomes a bigger issue before shelling out for a new one.

 

[E55BOF]

He also told me if you start it like a normal car ie. turn and hold the key in the Start position until it fires, it starts every time.

I too have a '98 E55. I always start it by turning and holding the key until it fires (pretty much instantaneously, except for the time the fuel pump seized...); I wasn't aware there was any other way.

 

[def90cars]

I too have a '98 E55. I always start it by turning and holding the key until it fires (pretty much instantaneously, except for the time the fuel pump seized...); I wasn't aware there was any other way.

All my Mercs you don't have to hold the key.
Just flick to start and release. The car starts itself.