Technical Help required please

[jamesd84]

Hi,
Car has developed a fault over the last few days which is gradually getting worse, it started as follows:
From cold start would start straight away the revs would drop below 500rpm the after a few seconds would go to just over 1000rpm then settle at 800 ish.
Now it starts and runs for 2 seconds bogs down and stall and brings up a message saying start stop not avialable (probably because there is a fault somewhere)
Once its been running for a few minutes it then runs normal again.
Also ifs its started left running for a few minutes then stopped the next time it starts fine.
Has plenty of diesel and battery is in a good state of charge.
Car is a 2014 1.3 multijet 4x4 30k miles.
My first thoughts would be glowplugs, but it starts straight away with no smoke or lift pump, if it has one?
Any help would be greatly appreciated as dealership service department is closed now until monday

 

[jamesd84]

will add a video shortly

 

[jamesd84]

[ame]https://youtu.be/CZwC3c6F7Fc[/ame]

 

[murphyv310]

Faulty fuel pump, air leak on fuel filter (has it been replaced recently?) Temperature sensor faulty?

 

[jamesd84]

Don't think it would be the temperature sensor as glow plugs are working and temperature gauge works.
Will be testing the fuel pump in a bit as i think that could be the issue, no fuel leaks anywhere and as I can hear a pump umder the seats i'm guessing it has a lift pump. Would explain why it starts and then stop again as there would be fuel at the high pressure pump until it gets starved

 

[Goudrons]

It could be rail pressure related.
I've seen similar problems before.

It's a tight balance starting a modern diesel.
There needs to be a certain crank speed on the starter to create the required rail pressure to sustain a clean start and idle.

It will have different strategies for hot and cold starts due obviously to the temp of the engine and fuel. The up shot is it tries a bit harder to start from cold than warm so it changes perimeters between the two, but everything's got to be right to do either.

Things like injector timings alter, it should hold off slightly when cold to allow the rail pressure to build, glow plug use, from cold it'll hold them on a bit longer.

Also, the returned fuel from the injectors alter, cold and it will pump it back around the hp pump which helps heat up that bit of fuel and aid cold running, but if it detects the fuel returning is hot it sends it back to the tank.

Also sorts of things can effect these things.
Obvious ones this time of year are battery related, it takes a big whack when cold starting, cranking the engine and hp pump, heating the glow plugs, powering the injectors all from a cold battery (yours was "possible icy").

It might appear the battery is ok as it's sounds like it's cranking fast enough (though from the first cold start in the vid, it fired rather quickly) but that's only one part of what it needs to do and it'll dedicate most of what it has to the crank.

You could try charging the battery up or hooking up a jumper battery to see if this is the case, if it starts fine with a jump, the battery is on it's way or it's just too cold to produce the right levels of power.

It's usual to help it out from a really cold start, see if this works next cold start.
Turn on the ignition and allow a few seconds for it to heat the plugs.
Hold the clutch pedal down, this takes some weight off the starter motor as it's not having to spin the gearbox.
Hold the key over a second longer on crank as it fires to help with engine speed.

Other than that, things like a fuel leak (or air entering the fuel system), bunged up fuel filter, excess injector leak off, iffy rail pressure sensor or it's not detecting it's actually a cold engine or fuel could be the issue.

 

[Queenie the green qubo]

Hi I have a Fiat qubo and I want to ask if all qubo have a cabin filter?

 

[jamesd84]

Ok so this morning i decided to connect a piece of pipe to the drain on the top of the fuel filter, open it and turned ignition on. There was quite a lot of air coming out followed by pure diesel.
Closed it off and car started fine, no hesitation or stalling, so suspect that although it has an electric lift pump it is still possible to have an air lock in the bottom of the fuel filter.
Also worth noting that i changed the filter about a month ago but it had been fine up until now.
Thanks for everyones advice
James

 

[Goudrons]

If it returns, it could be drawing in air around the filter housing.

If it gets bad, it could air lock the rail and fail to start.
So crack open the injector union on the end injector and flick it over on the starter until it spits out fuel.

 

[murphyv310]

If it returns, it could be drawing in air around the filter housing.

If it gets bad, it could air lock the rail and fail to start.
So crack open the injector union on the end injector and flick it over on the starter until it spits out fuel.

Yes that's what I thought. The 62 plate MJ Doblo van did this a couple of weeks after a service, when it went back the dealer told us the filter was a bit loose?? Was fine after so may have been drawing a tiny bit of air, enough to build up after a couple of weeks to effect starting.

 

[jamesd84]

Update; car started fine this morning after sitting for 24 hours and it was -2 and snowing heavily.
Did notice that on turning on the heated windscreen that the lights dimmed quite a bit and the idle speed increased so suspect battery isn't fully charged (I was going to charge it but it was below freezing, so didn't want to risk it)
Did 80 miles today in the snow so it should have got a decent charge.
On a side note I was surprised how great the panda was in the snow and ice, there were a couple of icy slopes that other cars were struggling with and the panda just went up them without any drama. Running Michelin cross climates and to be honest wasn't expecting that much out of them

 

[jamesd84]

Unfortunately the problem has returned and its ever worse now, once the car starts again the idle speed is over 1000rpm and hunting very slightly.
I think it might be stalling the first time it starts as soon as the alternator clutch activates.
Going to ring the dealer in the morning and see if they can book it in as at the rate its getting worse it won't be running at all by Christmas.
Doesn't appear to be any air in the LP fuel lines

 

[Goudrons]

Have you tried to bleed the fuel filter again?

What tends to happen when cold, is the injector spill off fuel recirculates around the hp pump, rail and back to the hp pump (or fuel filter).

This saves the lift pump pushing and the hp pump dragging lots of cold fuel up from the tank and helps warm/thin the fuel up already in the injection system.

Once it's all warm, it then diverts this spill off fuel back to the tank, which will add a little heat to the cold fuel in the tank.

So now when starting from cold, any air trapped can't vent in the tank, it just gets stuck going around and around this closed loop.

I suspect it's drawing in air around the fuel filter housing as the issue started soon after the filter change.

There have been similar posts regarding these filters.
There is a special tool to undo and tighten the tops, hand tight isn't quite enough to seal them properly.
Also the seal might require changing.

Another suspect is the hp pump, they have been know to leak from one or more of the three oblong cover plates, they usually leak out, but a leaks a leak and air could enter.

 

[jamesd84]

The filter on mine has 6 torx bolts on the top and is all metal, it is the element that has the seal on it, this is trapped between the bowl and the lid.
I have checked there was no air present this time. It does seem like air that is trapped in the HP circuit though I suppose it could even be drawing air through the leak off pipes if it is then being recirculated, depending when the garage can have a look I might remove the air filter and have a look at the leak off pipes etc when I get home from work.
Thanks for your help

 

[jamesd84]

I've had a bit of a breakthrough on this; If I start the car without depressing the clutch it starts fine with no cutting out, If I press the clutch whilst starting it cuts out and says start&stop unavailable.
when in 1st gear the car revs itself when releasing the clutch to pull off (which is normal)
seems really odd to me but thinking about it the problem started when I decided to dip the clutch to give the starter a bit of a break.
Can anyone shed any light on this?

 

[AB100]

I've had a bit of a breakthrough on this; If I start the car without depressing the clutch it starts fine with no cutting out, If I press the clutch whilst starting it cuts out and says start&stop unavailable.
when in 1st gear the car revs itself when releasing the clutch to pull off (which is normal)
seems really odd to me but thinking about it the problem started when I decided to dip the clutch to give the starter a bit of a break.
Can anyone shed any light on this?

You know there's a switch on the clutch pedal that causes the annoying rev-rise effect right? This is something a few of us have disabled. Perhaps it's time you executed the Murphymod.

 

[jamesd84]

Yeah I know about the switch; how does it restart the engine if it stops due to start and stop if it doesn't know the clutch is depressed?
If it still works I will remove when I get the car back, as its bloomin annoying.
Car is with Motorvogue Kings Lynn at the moment to look at the issue (along with the clutch clattering/vibration), they've given me a Tipo to borrow

 

[jamesd84]

Just got car back from dealer, they found a fault with the fuel filter housing and have replaced that. Seems fine so far, must have just been coincidence with the clutch I guess as it cut out on them. Just goes to show that air can leak in through a small gap but diesel won't necessarily leak when under pressure.

 

[jamesd84]

Have you tried to bleed the fuel filter again?

What tends to happen when cold, is the injector spill off fuel recirculates around the hp pump, rail and back to the hp pump (or fuel filter).

This saves the lift pump pushing and the hp pump dragging lots of cold fuel up from the tank and helps warm/thin the fuel up already in the injection system.

Once it's all warm, it then diverts this spill off fuel back to the tank, which will add a little heat to the cold fuel in the tank.

So now when starting from cold, any air trapped can't vent in the tank, it just gets stuck going around and around this closed loop.

I suspect it's drawing in air around the fuel filter housing as the issue started soon after the filter change.

There have been similar posts regarding these filters.
There is a special tool to undo and tighten the tops, hand tight isn't quite enough to seal them properly.
Also the seal might require changing.

Another suspect is the hp pump, they have been know to leak from one or more of the three oblong cover plates, they usually leak out, but a leaks a leak and air could enter.

Credit where credits due it looks like you were correct, I heinsight I should have spent a bit more time looking at the filter, but it's been bloomin cold
Thanks

 

[murphyv310]

Hi.
After 8 years of repairing industrial cleaning equipment and the majority pressure washers, i can assure you that air is an awful lot harder to "suck" than a liquid, any tiny air leak will cause all sorts of issues. Same goes for fuel filters, pumps and pipework even more of an issue with diesel in the cold when the fuel viscosity gets thicker.