Mysterious Dying Engine

[hydorah]

My '99 E55 is doing something very strange

Was cutting out in traffic every now and then, so I checked and cleaned the MAF - all OK there - and replaced the crank sensor

This seems to have have taken care of sudden cutting out when pulling up in traffic, but there is one remaining issue which is more annoying than it is troublesome

50% of the time when I start the engine from cold, it dies after about a second

Restarts just fine and I can make my journey. Other than this car runs fine. I'm thinking of getting it scanned for codes but I thought I'd see if there's an obvious culprit for the behaviour

Cheers!

 

[m2287]

Crank position sensor

Edit - just saw that you have already done that! Might need a new MAF? I cleaned one on my c class ages ago and it did nothing replaced it and I was off!

 

[markjay]

Cam positioning sensor...?

 

[hydorah]

Experimenting

Thanks for the suggestions

I tried it with the MAF disconnected and got the same behaviour with addition of an unstable idle, so I think that suggests the MAF is not to blame

I've located the cam position sensor, looks a lot easier to change than the crank sensor so I may as well give that a shot

I'll report back on my findings!

 

[hydorah]

Early Indications are Good

So... I decided to remove the cam shaft position sensor to get the part numbers and it looked like it had a fair bit of baked on oil all over it. Couldn't see any shiny stuff on the end of the sensor

So I sprayed it with WD40, polished off the muck, refitted it and since doing that the car has started and not cut out on the initial attempt 5 times out of 5

I'll see how it goes over the next few days but that cam position sensor suggestion seems to have been a hit!

Awesome, cheers!

 

[hydorah]

Still happening... But I have a hunch

This problem is still around!

No trouble codes on my scanner

But I remember this started happening after the RAC had replaced my battery

I recalled it was physically noticeably smaller than the original one

So I checked the specs, the one in the car is 75A/h where as the listed fitment in a couple of places I checked is 95A/h

Do any of you guys think that could that have anything to do with it?

I'm thinking I could give the RAC some bother about it in any event as it's not a correctly specced battery

Thanks for reading! And if you have an idea or opinion to toss into the hat, please do!