does diesel foam as it enters the cylinder

[Stubby]

Are you doing the little bottles or the 5 litre ones?

 

I use the little bottle every 3 or so tanks (when I remember usually). Cleaned up the dirty only ever used in the city TDDI transit we recently bought.

 

No ! Only the small bottles

[greatdane]

Hey folks went and picked up the L200 the other day which had been sat up for seven months according to the seller. Cranked it over for ages but couldn't get it to start. Got it home and pulled the fuel filter off and emptied it into a clear bottle. The diesel had separated into three layers, bottom layer remotely resembled something oil based, a thick layer of curdled milk, and a layer dirty water. Removed the injector pipes and they were full of the same thick creamy gunk, removed the injectors themselves and even they were clogged with it. I disconnected the fuel lines running from the tank to the filter, filter to pump, and pump to injectors, blew them out and re fitted them along with a new diesel filter. I put the main fuel line from the tank to the filter into a 5L tetra can full of fresh diesel and started cranking the engine over with the injectors disconnected from the pipes. Did this in ten second bursts for about half an hour so as not to burn out the starter motor. Thankfully the fuel pump still works as each pipe fired in sequence. Initially what came out of the injector pipes was the same thick creamy gunk but after a while it thinned and started to smell like diesel. However it is still cloudy and i'm just wondering if there is more gunk to be flushed out or does the diesel cloud with oxygenation during its journey to the injectors?

i spent 29 yrs working on diesel motors/injection systems and they work to such fine tolerances lubed by the diesel fuel,hence the large amount of fuel returned to the tank,that any long term usage with water in the fuel system reduces the pressure generated by the pumps,sometimes,180 bar,or 180x 14.7psi,and greater with common rail engines,that they fail to inject fuel into the cylinders from the injectors,which are designed to only open the part that injects fuel into the cylinder at pressures near to the pump pressure under perfect conditions,the water and crud that enters the pump wears the rotors away lowering the pressure generated,any water in a modern diesel system is the kiss of death to it,any water/crud coming out of the injectors pipes is a bad sign and poss wont generate enough pressure once its all built up under cranking over,hope this dont scare.or upset you but years of seeing non starts due to worn pumps killed by water is a regular thing caused by filters not getting changed,and the biggest cause of water in fuel tanks is condensation in the winter caused by hot fuel being returned to the cold tank,in the winter always keep the tank full as poss to keep the fuel cool as poss,hope this helps,spent many years solving pump/injection problems,i see you have fuel coming out of the pipes with no injectors fitted,this will happen,but if the pump pressure is reduced it will not open the injectors,it is designed to do this to prevent premature injection before the piston is in correct position,its all very complex,but any wear will not trigger the injection

Edited October 3, 2016 by greatdane

[TimberCutterDartmoor]

i spent 29 yrs working on diesel motors/injection systems and they work to such fine tolerances lubed by the diesel fuel,hence the large amount of fuel returned to the tank,that any long term usage with water in the fuel system reduces the pressure generated by the pumps,sometimes,180 bar,or 180x 14.7psi,and greater with common rail engines,that they fail to inject fuel into the cylinders from the injectors,which are designed to only open the part that injects fuel into the cylinder at pressures near to the pump pressure under perfect conditions,the water and crud that enters the pump wears the rotors away lowering the pressure generated,any water in a modern diesel system is the kiss of death to it,any water/crud coming out of the injectors pipes is a bad sign and poss wont generate enough pressure once its all built up under cranking over,hope this dont scare.or upset you but years of seeing non starts due to worn pumps killed by water is a regular thing caused by filters not getting changed,and the biggest cause of water in fuel tanks is condensation in the winter caused by hot fuel being returned to the cold tank,in the winter always keep the tank full as poss to keep the fuel cool as poss,hope this helps,spent many years solving pump/injection problems,i see you have fuel coming out of the pipes with no injectors fitted,this will happen,but if the pump pressure is reduced it will not open the injectors,it is designed to do this to prevent premature injection before the piston is in correct position,its all very complex,but any wear will not trigger the injection

 

This is a good post, made even greater by the tragic illustration that is the Penlee Lifeboat disaster. MV Union Star couldn't restart engines for this very reason, with catastrophic and far reaching consequences.

[flatyre]

Much appreciated Greatdane I will refit the injectors to the pipes tomorrow and see if they still work, I found a hole in the top of the diesel tank right between the cab and rear bed, there was a tiny dent which allowed enough water to gather to form a hole, i'm hoping this happened while she was parked up so she didn't run on the polluted diesel, there was no sign of corrosion on the injectors either, very clean considering the age, which makes me think the previous owner was telling the truth when he said it was running when parked up. Failing that I can get a good used pump for £100 from the guy I got the replacement injectors off.

[greatdane]

Much appreciated Greatdane I will refit the injectors to the pipes tomorrow and see if they still work, I found a hole in the top of the diesel tank right between the cab and rear bed, there was a tiny dent which allowed enough water to gather to form a hole, i'm hoping this happened while she was parked up so she didn't run on the polluted diesel, there was no sign of corrosion on the injectors either, very clean considering the age, which makes me think the previous owner was telling the truth when he said it was running when parked up. Failing that I can get a good used pump for £100 from the guy I got the replacement injectors off.

 

just make sure that any replacement pump will match the settings of the injectors,ie the pressures that they operate at,as there can be many variants,so can lead a good pump not having the correct pressure to open the injectors,even tho the pump is fine,its a very complex thing and they must match each other in operating pressures,hope this has helped you in sorting out a bad situation,but you could be very lucky and get away with it if there was not too much water through the pump,regards gdane