Om651 not starting

[alexanderfoti]

16.3:1 compression ratio ends up at around 250 psi.

You ideally want less than 10% variation between them. They all seem to have enough compression for the engine to run though.

 

[Kev555]

Thanks Alexander, thought there was enought to make the engine run but unsure with this type of engine and all

 

[LostKiwi]

I suspect air in the fuel lines is your issue. As Star said it needs bleeding properly.

 

[Kev555]

I havent disregarded Star and mr mb recommendations Lostkiwi, but im unsure what to look at next. The non starting symptoms before and after i replaced fuel and filter are the same. Just thinking something is wrong somewhere other than the bleeding issue. but at least if the compression ratios are passable i can look for a star diagnosis but nobody within 40 miles of me with that equipment. prepared to test as much as i can myself if possible for now. Of all the engines i had to get the om651

 

[Steve@Avantgarde]

Steve I have 1 bar pressure when ignition on and 3 bar when cranking engine iirc, Does this sound right? Everything i checked on the scanner last night all seem to be working as they should but im not up on what the value of the sensors should be if i got that correct?

Nope doesnt sound right at all.

You should 3.8-4.2 delivery pressure from the pump and then 150+ bar on crank and 300bar at the fuel rail running.

You have no fuel pressure.

I would start by measuring the delivery pressure somewhere after the fuel pump in the tank. Make sure the system is leak tight or you will get a false reading. If you have anything less than 3 bar I would say the fuel pump in the tank is the issue. If you have 3+ bar then I would say the issue is the high pressure pump.

 

[star]

How old is you fuel filter and check you haven’t put petrol in it.

 

[Kev555]

Nope doesnt sound right at all.

You should 3.8-4.2 delivery pressure from the pump and then 150+ bar on crank and 300bar at the fuel rail running.

You have no fuel pressure.

I would start by measuring the delivery pressure somewhere after the fuel pump in the tank. Make sure the system is leak tight or you will get a false reading. If you have anything less than 3 bar I would say the fuel pump in the tank is the issue. If you have 3+ bar then I would say the issue is the high pressure pump.

Sorry Steve my bad, that should have been on cranking the engine the fuel pressure started off about 250 rising to 300 after about 5-10 seconds of cranking. the tank pump reading at 1 bar is right iirc. i will check the fuel pressures again just to confirm. The tank pump is buggered then if it was only showing 1 bar and you say it should be 3.8 to 4.2 bar

 

[Kev555]

Hi Star i replaced the fuel filter last week after i drained the tank for fear of contaminated diesel or petrol traces in it

 

[Kev555]

Sorry Steve my bad, that should have been on cranking the engine the fuel pressure started off about 250 rising to 300 after about 5-10 seconds of cranking. the tank pump reading at 1 bar is right iirc. i will check the fuel pressures again just to confirm. The tank pump is buggered then if it was only showing 1 bar and you say it should be 3.8 to 4.2 bar

Sorry Steve i got it wrong must have been looking at the rail pressure when ignition was on. eventually after searching through scan tool i got the tank put pressure in the sprinter diagnostics section.Tank pump pressure is 4.25 bar when ingnition on so i think all is good there. really sorry for posting incorrect info on that, i will be more careful in future with accuracy and not go from 2 week old memorys lol . Rail pressure is 1 bar when ignition is on and rising to 250-300 when cranking. going to check with a manual meter this incoming week to be sure.

 

[Kev555]

Going to check for air in fuel line as i got a piece of clear plastic tubing and metal splice pipe from an old donor filter lying around shed today. just need to pick up a extra jubilee clip tomorrow and i will post back results. At least then i can rule any problems down to the general engine area. With all you guys knowledge i will hopefully get there in the end if you havent all done a runner lol

 

[Kev555]

Had a snow day from work today so started on the vito again. checked for air in fuel lines and none to report so tried a sniff of easy start (Thanks uncle benz ) and after a few trys she fired and what a relief that was happy days but all is not completely well. once started when i give the van a rev or two theres lots of grey-white smoke same as the day it broke down which smells more of exhaust fumes rather than strong fuel smell. once i start the van i can rev her as normal but if i let her sit a minute she wont rev past 1500 and very sluggish to get to it. egr malfuntion fault has shown up once again on fault codes. i know some of you guys mentioned Egr could be choking the engine think it was uncle benz iirc . so just wondering is that the cause of all the smoke as engine is running smooth enough

 

[star]

Classic of symtom of fuel system needs bleeding. You cannot do this properly by undoing a few fuel lines.

 

[Kev555]

thanks Star, that would be handy if its just that. I wouldnt chance undoing anything on high pressure side of pump anyways with the pressures involved. Just going to put up a few screenshots of codes and datastreams of vito at idle if i can figure out how to do this just so we can narrow this down to definate bleeding problem. took van for 1/2 mile drive, van felt like it was choking itself couldnt get more than 20-30mph and medium grey smoke from exhaust. there was 5 fault codes logged after this run.
1 the soot content of the particulaten filter is too high. there is a component fault
2 communication with the starter or alternater has a malfunction(this code has been there since i bought the van)
3 component relais klemme 87 has an electrical fault or open circuit ( new one to me never seen this one before)
4 the teach in of the operating parameters for cylinder 1 has a malfunction( seen this code before regular on the van( prob because the injectors need coded to brain?)
5 the soot content of the particulate filter is too high

 

[Kev555]

These are the datastream imges with van running at idle if any techs spot anything not right as i dont have a clue what the proper values should be

 

[Kev555]

More images below these are of the EGR circuit datastream at idle. If any techs spot something amiss. sorry one of them is sideways

 

[Kev555]

If any more images are required please let me know and i can post them up. found a good indie not that far from me. dont know if he has star but he is excellent at diagnostics from what i gather and has worked on mercedes vans. If i cant make any more headway i will bite the bullet and send her his way

 

[Uncle Benz]

Exhaust back pressure is the only thing that stands out to me. Seems high, but I'd welcome comment from others.

 

[LostKiwi]

Exhaust back pressure is the only thing that stands out to me. Seems high, but I'd welcome comment from others.

The value of running smoothness for cylinder 1 is vastly out of kilter with the other three.

 

[Kev555]

Thanks guys, dont know about the exhaust back pressure uncle benz but ive seen that injector out of balance reading before Lostkiwi but it was on cylinder 4 before the injectors were replaced. can only assume its because they havent been coded to the ecu yet but not entirely sure as to that reading. The time i replaced number 3 injector because of black death and destroying it while removing it number 4 then started showing a similar reading. Still a possibility number one is faulty reconditioning but highly unlikely or as STAR said system isnt bled properly( just confirmed with supplier last week that injectors are solenoid reconditioned injectors not new and are replacements for the ones i left in). I have to take van to the firm who reconditioned the injectors to get the new codes in the ecu before i suppose i know if theres a fault unless any techs see a problem here. I for some reason am starting to get sceptical of the ecu throwing up so many codes in different ways since i bought the van. Has there been any issues with faulty ecu,s or main harness wiring on these models?

 

[Uncle Benz]

Didn't see the first set of pictures! Injector 1 looks potentially dodgy, but I'd check the coding first, if you haven't done it. As Star says, there is a proceedure for bleeding the system, but I've no experience of that fixing anything for me. It's difficult without seeing it, but it could be excessive fuel from one or more injectors causing the smoke or egr entering the intake when it shouldn't be. Are these Piezo type injectors? Show us a picture of one please.