D40 rail fuel pressure sensor

[Sami_b]

Hi all

My d40 2.5dci refuses to start.
Fuel filter is new
When trying to start there s no fuel going out from injector.
I don't know how to check if the problem is due to the rail fuel pressure sensor or the pressure relief valve

I used an odb2, but it doesn't found any error.

 

[Old.Tony]

That's not good news. There are a number of things that can get in the way.

Is fuel actually flowing past the filter and into the pump? Easiest way to tell if fuel is even in the line is to squeeze the primer bulb a few times. If you get to 5 squeezes or more, chances are fuel is not even getting to the pump.

If fuel is getting to the pump, it should be making it to the rail. If the injectors aren't opening, my first guess would be to look at the earth connection from the battery to the engine, then the injector harness. If the vehicle has a chip installed, remove the chip, or check the harness for signs of damage - look closely at the connectors for each injector.

There are other possible causes, but let's start with the easy stuff.

 

[Sami_b]

No fuel is going to the injectors.
But today i started it by hitting the rail pressure sensor while trying yo start the engine.
I don't know how this sensor works, i don't know if it can order the pump to stop delivering fuel to the injectors.

 

[jonney]

you might have air in the fuel line, try bleeding / pumping up the fuel filter plunger a few times .

 

[Old.Tony]

Hitting the sensor made it work? That would make sense if:

* The sensor had a spring inside it that had gummed up through some debris or varnish that was deposited by the fuel and hitting the sensor shook it loose

* The sensor had an erratic electrical connection and hitting the sensor made the connection work.

I admit you have an interesting diagnostic technique - if it doesn't work, hit it with a hammer until it does!

 

[jonney]

sounds like the old Holdens etc etc that had a needle and seat on the carbie and when the engine wouldn,t start you just tapped this needle / seat housing a few times and bingo of we go again. maybe this rail unit has a simular type of part inside that gets sticky and needs some tender loving care , or replacing.

 

[Hoody D40]

Hi Guys im Trav just joined good to meet you all Um guys try not to ash it lol a boiling jug of water poored over it will be much more effective and if your in vic i have a spare lol

 

[JLA]

Someone told me this but I have my doubts:

For all common rail diesels you have to change the engine oil quickly.
Within 10 minutes the new oil has to be added and the engine started.
Reason given:
The engine oil pump has multiplier effect for the rail fuel pump and this part of it would need bleeding after an engine oil change if not changed quickly.
Meaning you get no fuel pressure because the "multiplier" needs to be bled.

Does this ring any bells for anyone or is it bull?

 

[Old.Tony]

The fuel pump is a mechanical pump sitting on the right hand side of the YD25 engine driven by the primary timing chain (along with the vacuum pump drive below it). There are two sprockets on the fuel pump shaft, a larger one that the primary chain runs on, and a smaller one that drives the secondary timing chain which in turn drives the camshafts.

The fuel pump is almost a separate unit. Its internal lubrication is provided by the fuel, which is why it's not a good idea to crank the engine for long periods without fuel in the lines.

Because of that, there's no "time limit" on changing the oil that I'm aware of. The pump itself is considered (by Nissan) to be a sealed unit, and itself can produce 1700BAR (about 25,000 psi). It doesn't require a multiplier - the unit is quite a powerful pump.

 

[jonney]

i can not see why you would have to change the engine oil in a hurry [ quickly ] i have done heaps of oil changes on my nav which i will leave the engine fully drain for a good hour before i replace the sump plug and filter and oil.

 

[JLA]

I thought it sounded like BS.

 

[jonney]

what i have noticed on my 2.5 is theres a rubber hose going from the bottom of fuel/ injector pump to the engine sump and what this is for is to feed oil to the pump when the engine is running, it works like a re circulator so oil goes into the pump and back into the sump and so on. so really when the engine is not running i would say the oil in the pump would slowly drain back into engine sump until the engine is started again then the oil will be pumped back into the fuel / injector pump. this is why i can,t see why you would have to quickly change the engine oil to avoid any air pockets etc.

 

[bods]

Someone told me this but I have my doubts:

For all common rail diesels you have to change the engine oil quickly.
Within 10 minutes the new oil has to be added and the engine started.
Reason given:
The engine oil pump has multiplier effect for the rail fuel pump and this part of it would need bleeding after an engine oil change if not changed quickly.
Meaning you get no fuel pressure because the "multiplier" needs to be bled.

Does this ring any bells for anyone or is it bull?

Not on navaras, but I have heard of something similar on the new rangers. Apparently the oil runs out of the oil pump and you can't bleed the oil pump again or something... I don't know how true it is though...

 

[Black_Outlaw]

Service warning: Mazda BT-50 / Ford Ranger new generation 5cyl diesel models UP0YF1 – When draining the oil, ensure that the total drain time does not exceed 10 minutes.

Field reports indicated that there may be an issue with the variable-flow oil pump fitted to Mazda’s new generation BT-50, 5 cylinder common rail diesel engine.


A new feature in the BT-50’s engine is the variable-flow oil pump that helps maximize fuel efficiency. Rather than the conventional fixed-flow gear drive oil pump, it is accomplished with a chain driven oil pump located in the sump that matches the oil supply to the engine load. The variable-flow pump changes its capacity based on the engine’s demand for oil, by rotating the eccentric outer ring. This prevents wasting energy to pump oil that is not required to maintain engine operation.

These variable-flow pumps are much like power steering pumps, using vane elements in their design with the added ability to control flow rates at varied engine speeds. When the vehicle has the oil drained for an extended amount of time, the oil drains not only from the sump, but internally from the pump assembly. The vane type design appears to be less tolerable to being allowed to drain out and recover from that state thereafter.

Reports to Autodata are that if the engine oil and filter are changed in service and the oil is left to drain longer than 10 minutes, the oil pump may fail to prime and leave the engine in a critical no lubrication situation. Attempts to prime the pump by increasing the rpm fails to solve the problem, and will lead to component failure from lack of lubrication.

I think that says it all...

 

[JLA]

Yep, That must be it.