2000mercedes ml430.Runs fine until you come to apoint whe...

Hello and welcome to Just Answer My name is \*\*\*\*\* \*\*\*\*\* I've been an automotive engineer since 1996 and together we're going to solve this issue. I understand that having your trusted vehicle let you down can be frustrating as it rarely occurs at a convenient time, however I will do my best to either help you make the repairs yourself or at least understand the issue so you know what is involved. 1st thing to ask is do you have any check engine lilghts or other fault lights on?If so then plugging in ascan tool should be the next step as these will extract any fault codes and point to the issue As this sounds like a lack of fuel and could be a lack of fuel pressure from the electrical pump at the tank. 1st thing to try is to remove the fuel filler cap and then flick the ignition on whilst listening for the brief ‘buzz’ of the pump If the connections to the pump are corroded or damaged, then the pump could stop at any time or could not be running at full speed. Check that its relay switches in and out and the relay contacts are clean and bright – replace the relay if in any doubt and do the same for the fuse, Ideally measure the pressure at the injector rail (should usually be around 3Bar / 45psi +) and if this is low check the pump as described and consider changing the fuel filter as if this partially blocked this too will reduce pressure. You can also get this issue with contaminated fuel , if there’s water or dirt in the tank then either the petrol floats on top of the water or the filter sock on the pump is choked up – so if the other things check out then I’d consider pulling out the fuel pump and cleaning the filter sock And one other thing to try is to loosen off the fuel filler cap, as there’s a 1 way valve built into the cap to let air into the tank and so prevent too great a vacuum from being created as the fuel leaves the tank to the engine If this helps, then replace the cap with a new item

recently had problems with low fuel indicator lamo coming on and flashing when ideling for a short period of time,indicator lamp would flash repeadedly rather than just come on .When starts to give problems also check engine light comes onbcan turn vehicle off and sometimes it corrects problem.usually only occurs after ideling for short periods of timecant afford a phone call..limited income

OK thanks for the extra information this does sound like an issue with the fuel delivery system so try the simple test of loosening off the filler cap 1st as thats an easy fix however as you are getting fuel level errors too then I suspect the issue is with the pump inside the tank as this also contains the fuel level sender So I'd say to be prepared to have to replace the pump the next step should really be to plumb in a fuel pressure gauge at the engine end to confrim that you have low fuel pressure and then check over the pump power supply and consider a new pump

thanks mat,this gives me a place to start,first off ill get autozone to check code on check engine tomm.and i was posibly suspecting fuel pump,but with so many gadgets now and i dont have diagnostic equipt to check with.you have been a great help and ill let you know,could you possibly tell me where fuel pump is on this vehicle

the pump is lcoated inside the fuel tank and accessed by lifiting up the rear passnger seat cushion and removing a little blanking panel if the tank is full then it will need to be drained a little 1st see here for how its done https://www.youtube.com/watch?v=Vu8RSUFlNl8