Technical westray

[westray7]

Advice please. X reg jtd multipla, will not start.
Have studied all I can find on the forum but a bit stuck now with how to proceed.
We are on an outer island in Orkney, no fiat dealer for 150 miles. Might manage to borrow a ODB2 reader but at this age it may not tell us much. Experienced with pre electronics etc diesels.
Car history is:
Last 10,000 miles on our own quality biodiesel. A very useful and much loved car.
Injector symbol for some time, low power (EGR or throttle pot/ connections perhaps) but useable then laid up for a year with a broken sump. Repaired with Isopon. Started OK after repair. Used for a week, always started but sometimes slow to start. No misfire on starting, no smoke, behaved like it was having to pump fuel through. Once running, ran as usual, low on total power but no misfire and perfectly useable. never failed after starting.
Now will not start at all.
Wondering if the high pressure pump has been doing the sucking from the tank?
I assume there is a tank pump? Should I be able to find a resettable cut off valve? (referred to in some posts) If so where? How do I check if the tank pump is delivering to the high pressure pump?
More advice and suggestions please. Thanks in advance

 

[MultiPa]

There is a tank pump - item 4 on this link. Not sure if the high pressure pump would be strong enough to pull fule through on its own though.

You can check fuel is coming from the tank by disconnecting the fuel line before the fuel filter and trying to start it - if fuel comes through then you know it's definitely not the pump.

If it doesn't it still might not be the pump - is there any chance the fuel lines have got clogged with biodiesel sitting in them for 12 monhts? Does bio settle?

If the fuel is coming through to before the filter then my bet is that the filter has got clogged. Fingers crossed it's as simple as that - let us know!

 

[westray7]

Hi
Fuel pump in the tank is definately working well! big spray of fuel if I slacken the delivery to filter pipe.
Fuel filter is not blocked as fuel comes through the filter fine to the outlet. Again a good spray.
If I close that and open the return to the top of the filter then it comes fine from there too.
I assume that means the high pressure pump is filled.
Now what?

 

[MultiPa]

Hmm - not sure really. Do you think the loss of power is related to the not starting? It'd be good to know what the scanner says, if you can get hold of one.

I'm not an expert by any means, but I did have a 2.4 JTD that wouldn't start once and it turned out it was the top dead centre sensor that had failed. The car turned over as normal and sounded like it was going to start, but never did - I presume because the electronics wouldn't let it. It was down on power at the time because it needed a new MAF, but that was unrelated.

Not sure that helps really - the TDC was only £30 or so.

If fuel is getting through, and there is nothing mechanical that is wrong then I guess it must be electrical though?

 

[MultiPa]

Any luck with fixing it westray7?

 

[westray7]

Hi
No not yet. Do not think it is a fuel issue. Hoping it is the crank sensor but there were no cutting out when hot signs, just either willing to start easily or not at all so hoping it is a connection issue on the crank sensor. Have to jack it up and try to sort. Will post re progress.
Cheers

 

[MultiPa]

My 2.4 JTD didn't cut out when it was hot when the TDC sensor went, it just either started or didn't start. You could get it to start eventually with a big enough push, I presume because once the pistons are moving it assumed everything must be ok - I don't know - typing that it doesn't sound like there is much point in the sensor if it ignores it when it is running, and if some cut out when it gets hot it can't be the case?

If everything else seems ok but it sometimes starts and sometimes doesn't I'd definitely try a new TDC assuming they are as cheap for the 1.9 as they are for the 2.4.

 

[Jagernaughty]

Check for exhaust leaks on the front section. a smal leak would explain the earlier lack of grunt, a bigger leak might explain the non starting. (currently replacing my frint section due to the B.S. flexi pipe bit leaking.)

 

[jwmultipla]

my old multi used to stall at lights and then would not start, turned out to be crank sensor. there is a modyfied sensor out that is all plastic. the old ones were or had some metal parts to the body and if you have had it layed up for a year then it may be that the sensor has failed. with electronic components they usually the work or they don't. if you also have a lack of power then that will be something else, usually the maf or mass sensor located on the inlet side near the air filter. again if not used it could have deteriorated. try disconnect the maf sensor and see if that improves things on the power side. it should have reasonable power up to about 3000 rpm as the ecu detects a fault on the maf and sets things to a 'default' setting, after 3000 it will probably be a bit numb but is a good place to start.

Justin

 

[Moriarty the mundane]

Pre heaters all working? I have heard of Multis starting with no preheaters working (disconnected for diagnostics) but perhaps that is the answer?
Moriarty
P.s. Is/was there a flashin light on your dash once started? I just cant picture the logo but think its yellow from memory...if so its a pointer in the right direction.

 

[westray7]

Crank sensor changed today. Still not starting. I assume preheaters are fine as there were not the usual misfiring start up and white smoke symptoms when it was working.
Now about to scrap an otherwise good car as any major guesswork component swopouts will cost more than the car is worth.
Is there any home spun way to test the high pressure rail fuel pressure? I understand you can get a leaking injector so the pressure cannot rise enough. Is there any sensor that can be bypassed to con it there is enough pressure there?
Any more ideas please?

 

[Bucksbeekeeper]

Crank sensor changed today. Still not starting. I assume preheaters are fine as there were not the usual misfiring start up and white smoke symptoms when it was working.
Now about to scrap an otherwise good car as any major guesswork component swopouts will cost more than the car is worth.
Is there any home spun way to test the high pressure rail fuel pressure? I understand you can get a leaking injector so the pressure cannot rise enough. Is there any sensor that can be bypassed to con it there is enough pressure there?
Any more ideas please?

Hi all,
I have a1.9 JDT Doblo which I was running on good quality Biodiesel for a year. Changed the fuel filter every three months and all was well. One day it refused to start. Just like the posts above , it nearly starts but not quite. I can start it by towing it. Fuel going on and out of the fuel filter so no problems there. The car has been laid up now for 6 months now while I drive another 1.9 Doblo but with only 50% Biodiesel. Would love the fix the old one as it is such a nice car.
Have read all the posts. The answer is nearly there but not quite. Any advise?
ps. No warning signs on the dashboard.

While I am at it, the hand break light on the new one is intermittent. I have cleaned the sensor switch and sprayed it. How do I fix this as I fear that is a MOT failiar.

Bucks Beekeeper