Leaking JTD Multipla injectors. Advice req

[Danblez]

Tim, is it worth sticking all the original injectors back in to see what happens? If you could get to the original situation and then swap one injector at a time?

 

I feel your pain!

[cort16]

[Lankytim]

It's got the original injectors back in, all tested and calibrated. So I'm back to square one but a few £££ lighter

 

I thought Fiats were a paragon of reliability. I must have a friday afternoon one.

[Lankytim]

Right. I found the bypass hose, that goes back to the tank from the pump. It seems to have that round valve thing controlling it. When I turn the engine over diesel comes out of the pipe at a fair rate, would this prevent the rail getting the right pressure?

[jonathan_dyane]

Put mole grips on hose (not too tightly) and attempt start?

[Lankytim]

No, the rubber hose wont take 4000000 bar and will blow up

[Mr_Bo11ox]

good idea apart from that though

[Mr_Bo11ox]

When I worked at Perkins a photo came round of some lad whose arm had been LITERALLY flayed to fuck by a jet of mega high-pressure common-rail diesel, it was horrendous, flayed was defo the right word, the skin was hanging off his arm in bacon-rasher-sized strips. If that wasnt bad enough the idea of having loads of diesel in a massive open wound was enough to make anyone heave. Awful. Be careful out there kids!

[twosmoke300]

Some of the newer cr stuff is 3000 bar ! Mental when a normal Xud type injector was 130 bar

[cort16]

At one point in time computer processors became so complex that not one person on the planet understood them. As in within intel even the biggest tefal heads in the company has no idea how it all works as it's so complex. They can sell you the concept but don't know detail of all the processes .

 

This is now the same for common rail diesels

[Lankytim]

I bet CR diesels become self aware soon and try to destroy mankind by turning them into flayed bacon.

[cort16]

lets hope so

[Lankytim]

Right, got stuck in to this, on my day off work.

 

Swapped the pressure regulator- DID NOT WORK.

 

Decided to change the whole HP pump- I found this can be done pretty quickly as you can bolt the pulley to the backplate through a couple of holes and this negates the need to take the cam belt off. Of course I  fucked this right up by turning the engine over the wrong way on the cam pulley bolt and causing the cam belt to slip over the crank pulley. MOTHAFUKKA!!

 

After taking everything to bits I found the pump came off very easily, I wasn't looking forward to this job but it's all very straightforward.

 

Stuck it all together again and guess what? It still doesn't  bastarding work!

 

I have no idea what the problem is now, but it seems like I've swapped the pump for no reason.

[Lankytim]

Ok peeps, Today I got down to Halfords and bought a deep 27mm socket with which I removed the fuel rail pressure sensor. I have a good spare, but it turned out to be the wrong size (too small) Before I replaced the sensor I stuffed some rags under the hole in the fuel rail and cranked the engine over, the idea being that any crud in the rail would be purged from the hole.

 

Nothing came out, not even a dribble. There seems to be NO fuel AT ALL coming from the HP pump! I cleaned the original sensor up, which had some odd yellow shite on the end of it and stuck it back in.

 

Could the HP pump be air locked? Everything i've read says they self prime but I honestly have no idea.

[Richard]

This thread makes me feel better about the C5's problems, and also strengthens my view that 21st century cars can eff off.

 

Is the low pressure pump at the tank end working? 

[Lankytim]

Yep, loads of fuel getting to the HP pump.

[alf892]

So you have lots of lp fuel actually getting to the hp pump? And then nothing out the hp side?

 

There isn't a relief valve on the hp anywhere is there ?

 

Just thinking as it seems odd.....and if no valve then hp pump must be fkd ? Mind you I don't think there would be much volume from the hp....just pressure

[alf892]

A proper gauge test still seems the only way to go though.....otherwise it is guess and spend

[twosmoke300]

Try disconnecting the control valve /solenoid on the pump and cranking . If you have pressure then its a control circuit problem. This test only works on normally open solenoids though.

 

Sorry if im teaching granny etc but go online and have a good read of how that particular system works . Much easier to diagnose faults if you fully understand how it works.

[Lacquer Peel]

[Lankytim]

The control valve on the side of the pump is normally closed and allows fuel to enter the pump when opened, otherwise it just goes back to the tank. I think this is where the problem is, this valve isn't allowing fuel to get through. I've half a mind to cut the plunger off the spare one and fit it so the pump is getting fuel into it. However, if it ran at all it would over pressurise and blow up I expect.

 

A proper gauge pressure test wouldn't work in this instance as there is FA entering the fuel rail from the pump.

[Bren]

Diesels - too clever for their own good.

 

Get a petrol - I will never buy another diesel.

 

Remember the scrappage scheme - the next motoring fatwa will be older diesels.

 

You heard it here first.

[Mr_Bo11ox]

Can you fiddle with the spare valve and see if 12v on its contacts makes it open? If so hardwire it open direct from the battery perhaps? For trial purposes obv

[twosmoke300]

What he said .

 

Shouldn't overpressure on tickover or cranking either

[Lankytim]

I put voltage across both valves and nothing discernible happened, to be fair they may be low voltage for all I know.

[cort16]

I saw one of these today smoking like an absolute bastard. Not a puff but the full smoke screen job.

No use obvz but it might make you feel better to know there's someone else facing multipla misery .

[Mr_Bo11ox]

'Multipla Sclerosis'

[twosmoke300]

Smoking is just showing off cos he has fuel

[Lankytim]

Right, this naught Mankipla has been replaced. We don't tolerate failure here at Lanky towers. 

 

We've got another Multipla. but this one runs. apart from being red, it's identical.

[dave21478]

If you are confident / brave, swap parts one at a time from the new one to the old one until the new one doesnt work and the old one does. This should identify what needs repaired so you can get the right parts and repair it.

 

I dont see how anything could possibly go wrong with this, and it will in no way leave you with two dead cars.