Ramodeys

My E55 keeps stalling after starting the car. It will run for a second then die. I changed the CPS and the relays and it still does the same thing. I can hear the pump priming and there is fuel going to the engine, at least when it first starts but then fails to deliver fuel to keep it running. I am not sure what it could be at this point. I have not been able to keep the engine running more than a few seconds and if I tap the accelerator, it dies even quicker. The E55 is from 2006 so it has the 2 relays in the rear. The relays show no signs of wear and the socket isn't melted. I also checked the fuses and they appear fine. What else should I check to fix this? The car was running perfectly prior to this, it first started when I jacked up the car to change the upstream o2 sensors but they were the wrong ones so I put the old ones back. I checked everything around it in case I accidentally disconnected something but I did not see anything out of place.

PieRat

check ur fuel rail pressure pump is probably kaput.

Ramodeys

By fuel rail pressure pump, do you mean the fuel pump that is under the rear seat on the drivers side? Do these die without warning?

PieRat

Yeah mate, sorry meant to say check ur fuel rail pressure (there is a nub you can connect a gauge to on another side). Fuel pump is in the back under the seat yep it can die without throwing a cel or a warning really. Mine went but I couldn't start the car, thought it was CPS like you did and eventually figured it was the pump as I had spark etc.. If you have spark its probably the pump IMO but you can check the rail pressure to be sure. If your in the USA you can cheat and get a free pump/tank replacement under warranty

Ramodeys

Thanks, I will call up the dealership and see if they can replace it under warranty. I have spark so then it must be the pump. I do not have a pressure gauge but when I poked the nub where the gauge goes, fuel shot out so it is pressurized and primes. It seems like it just loses the pressure when cranking over. If they can replace it that would be great.

Ramodeys

Thank you for that info. They said that it is covered under their warranty for the tank, pump, sender, and other bits. Basically the whole fuel system. The only thing that worries me is that if it isn't the fuel pump causing this issue then I will have to pay 205 for the diagnostic. I will get a fuel pressure gauge to confirm that the pump is broken.

PieRat

The warranty is for a leaking fuel pump/tank. TBH I think you could just pour some petrol over the manholes under the seat, put the sound deadening layer over top and the seat and when they look at it they'll just go 'oh look another leaking one yep replace it' lol. Thats what i;d do but im a cheeky boi.

Ramodeys

Lmao, I was going to ask if I should mess with it to make it meet warranty requirements but I thought it would anger some people on this forum. I’ll pour some gas on it and tell them there are strong fumes.