Help - engine died and won't start

[kiwi1973]

It was driving fine earlier today, then the first indication I had that something wasn't right was taking a corner and going back on the accelerator, but there was an unusual lag before acceleration took place. I stopped and restarted the engine but it took quite a few more turns than usual before it fired up (not glow plug related as engine was already warm). I then went for another drive but it was by then obvious that it was dying - it became difficult to maintain revs and Torque showed my fuel rail pressure was erratic.

There are no fault codes, which doesn't help. I believe it must be related to either the engine being starved of fuel or air. Off the top of my head the places to begin diagnosis might be:

1. Check if the throttle plate is actually opening, or whether it's gunked up and sticking. Torque shows the throttle fully open, but this presumably reflects what is being commanded by the ECU rather than what may actually be happening.
   
2. Throttle position sensor failed. Where exactly is this - is it on the throttle body?
   
3. Crank angle or cam angle sensors failed.
   
4. EGR? Seems unlikely. I have my own mod at the MAF sensor that keeps EGR closed.
   
5. A fuel starvation related issue. This shouldn't be likely to be the issue - as some of you will know I had my entire fuel injection system replaced about 4 months ago, including a new fuel filter then.

Any other ideas of where to begin with diagnosing this would be greatly appreciated. Lucky this happened just down the road from home.

[Travel Tragic]

Sounds like fuel, maybe a blocked filter. It only takes one load of dodgy fuel to block things up. Have you filled up recently? John

[NJV6]

Oh no! You will begin to think it’s posessed.

[christopher]

Do you have more than a 1/4 tank of fuel, if not the lower fuel pickup may be blocked

[Keithyv]

'Entire fuel system replaced recently' did this include the high pressure pump?
'Fuel pressure all over the place' means that it actually is all over the place (so maybe bad pump / blocked filter etc.) or a pressure sensor failure.

[kiwi1973]

Do you have more than a 1/4 tank of fuel, if not the lower fuel pickup may be blocked

I was initially minded to dismiss this because whilst my fuel is below 1/4 of a tank it's not that low - i.e. fuel light is not on. However, it then occurred to me that this is possibly about the lowest I've had it since all the fuel injection was replaced and fuel tank removed for cleaning etc. I wonder if anything could be different since they put it all back together - either in terms of the fuel gauge accuracy having been upset, or the pickup tube position altered. I happen to have a small jerry with diesel and I'll go ahead and add this to the tank just to eliminate the possibility that something as simple as having run out of diesel (even if not reflected on the fuel gauge) is the cause.

I will keep the thread updated with the final outcome - whatever and whenever that may be.

[kiwi1973]

I just ran down the road to where I abandoned the car earlier today. Sure enough the primer on top of the fuel filter assembly was completely soft and easy to pump. So I added the contents of my small jerry of diesel into the fuel tank and furiously pumped the primer until I could get fuel through. I got the engine started and just now drove the car home. It drove fine with none of the hesitation it was suffering from immediately ahead of dying this morning. So I think you can see where this is going - it just ran out of fuel! Yet the fuel needle isn't low enough to even bring on the fuel warning lamp. This simply must be related to the work done earlier in the year cleaning out my fuel tank and replacing all the injection components (due to a fuel contamination issue that I detailed in a separate thread). Either they've upset the accuracy of the fuel sender, or the pickup hose has been upset.

I know how much fuel I just added from the jerry and so I'll go and do a complete fill to the brim with diesel to see how much diesel I can add. This will tell me whether it is the fuel gauge inaccurate or the depth of the fuel pickup tube that is the issue. And then I'll have this rectified by the firm that carried out the fuel injection repairs. I suspect it will be the fuel pickup tube that is the issue - allowing the engine to run out of fuel whilst there is still actually sufficient fuel in the fuel tank. I don''t want this. We go touring to remote places and want to know that in a pinch we can access all the usable fuel in the tank (notwithstanding I'm aware you don't want too run to low, or allow diesel to get too hot).

In case any of you missed this in the video/photo section here's a short video from our most recent offroad trip - and it shows exactly the sort of places we don't want to have today's sort of issues arising.

https://youtu.be/qQjMAsLsdQg

[benckj]

My guess is the altered pick up level in tank. The sender and light work off different circuits so its unlikely they are both faulty.

Having replaced fuel pumps in other cars I know how the pick-up level can be changed by a few cm's due to position of the hanger & rubber mount. This is more likely if they installed an aftermarket FP rather than OEM. Might pay to ask.

Jim

[christopher]

This is what you are looking for

First pic is lower pickup filter 2nd is how you want it to look after cleaning.

This happened to me, that's how I know

[KiwiNTPajero]

i am guilty of going from full to empty al lthe time.I never get fuel until the light comes on,often well after the range has already gome to zero.I will check the ammount i put in as soon as the light comes on next time for reference.

[erad]

If your pre-filter in the tank is choked with gunk, this could cause you problems. The fuel level in the tank is always lower that the main filter, and therefore the main filter is always under slight negative pressure. Negative pressures equals air leaks, equals soft hand primer pump. Since someone obviously has had your Pajero fuel system apart, this is a good place to start looking.

I fitted a pre-filter to my NW Pajero, and the filter mount leaked air. I tried double clamps on the rubber to steel fittings, but no difference - it still leaked air. Eventually I took it to a mechanic and he removed the pre-filter and tested it with a vacuum pump. Bingo - it leaked. He put a new gasket/washer in the top if the filter body (where a hand pump would normally go, it was blanked off with a plug and that plug was leaking. Eventually he reduced the air leaks, but could not eliminate them. He got to about 20 inches of mercury. but could not make it tight beyond that level of vacuum. I reasoned that at most the difference between the bottom of the fuel tank and the pre-filter was about 500 mm, which would equate to about 1.5 inches of mercury. so that was well within normal operating range. I never had any problems after that event.

So if your pre-filter in the tank is choked, it could cause losses such that air will get sucked in. The possible symptoms of this problem could be that the engine will run but not go very fast. At slow engine speeds (eg idle) the main fuel pump will suck fuel into the common rail as fast as it can, but because you have low engine speed, it won't be pulling that much fuel from the tank. What fuel is not needed for the engine is returned to the tank. As you increase engine speed, the main fuel pump will pull more fuel from the tank, causing more losses at the in-tank filter, and if you have an air leak, it will not like it and the engine will stop Since someone has been paddling around with your fuel system, it is possible that they may have induced an air leak somewhere in the system. And as your fuel level goes down, you get more negative pressures (more air leaks).

[Piet Potjie]

I opened my fuel pick up up as a preventative measure. Found a post where some one found the valve contraption in the white plastic housing had fallen apart. Mine had also fallen apart. Not a very well made item / cheap. Some contention as to what exactly this valve is supposed to be for. My thoughts are it directs the draw of fuel from a higher level / away from the bottom of the tank and only once the level drops, allows fuel to be drawn from the lowest level. Either way this could cause a problem as it is not well made. I like the other poster decided to opt for reliability rather and disconnected it and my tank draws from the bottom.

[kiwi1973]

Update

Thanks for all the assistance and ideas. I could so easily have wasted a whole day following my initially intended hierarchy of diagnosis, which I set out in the first post, and none of it would have worked given there was no fault and the car had simply run out of diesel (I went for a good drive today and all is well).

Today I filled up with diesel to the very brim to see how much it would take. It took 81 litres and there would have been about 5 litres in there from the jerry can. There is something not quite right with this. I should have been able to add about 84 litres (i.e. 83 litres would get to the 88 litre limit of the tank + say 1 litre to fill to the 'brim').

I phoned the fuel injection firm to discuss and they asked if I'd hit anything on the bottom and dented the fuel tank..... this reminded me that indeed we did in July. A non serious rock impact to the fuel tank, but nonetheless enough to put a small dent in it. I didn't think too much of it at the time.

So the issues with the car now able to run out of fuel despite the fuel level not all out and fuel light not 'on' could be due to the dent in the tank as opposed to something done by the fuel injection specialists in March. It doesn't look like a 3 litre dent, so I'm not fully subscribed to this conclusion just yet. I guess I need to remove the plastic protector and get a better look at the dent.

How to remove a dent from a fuel tank? To any of you who have opened the top of your tanks would it be possible to access from there - bit of wood and hammer perhaps? Alternatively I have a spot welder specifically for use in repairing dents in automotive sheet metal. You just instantly spot weld to the metal and then are able to pull dents out. I'm not sure what the thickness of the fuel tank is and whether this would likely work.

An important point of note though is that this wasn't actually a breakdown - just out of fuel.

[KiwiNTPajero]

paintless dent removal outfit?

[NJV6]

What sort of dent is it do you know? If it doesn’t have a crease in it then compressed air works well.