Technical Multijet no start.

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Technical Multijet no start.

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When I rebuilt my engine I rushed the cylinder head and pretty quickly ran into difficult starting with white smoke etc etc.

So I’ve bitten the bullet, bought a replacement head and fully prepped that before taking car off the road. Two new inlet valves were needed spotted when trying to lap the seats.

I did the job with engine in car. However this is by far not the best option. Access is abysmal and the time to pull the engine & box would have been time well spent.

Anyhow the engine is back together but it (usually) won’t start. When it does, a touch of throttle stops it.

(1) my glow plugs are not working I believe it’s the plugs (11 volt type) as they don’t heat when connected with jump leads. However the weather is warm so it should start.

(2) My OBD connector is the right type but MES can’t see it. Probably faulty. Bugsy Mike came over with his professional kit which connected fine.

Immobiliser light goes out immediately.

We suspected lift pump pressure was low but get good pressure. So good that a leak test nearly had diesel everywhere!

When it starts, injection pump pressure rises fast to 270bar. Engine idles very nicely but stops when you touch the accelerator pedal. It then refuses to start.

We had an intermittent fuel rail temperature sensor but don’t know where that is.

We have not swapped the crank position sensor - don't believe in simply swapping parts.

I need to get a set of glow plugs and possibly a glow plug relay. Latter can wait until new plugs arrive. None of that should cause the problems.

Any ideas?
 
When it starts, injection pump pressure rises fast to 270bar. Engine idles very nicely but stops when you touch the accelerator pedal. It then refuses to start.
Is this enough on the Multijet ? I am sure it should be higher? I might be wrong but I thought it should be more.

Do I remember correctly that you did have an issue with the pump before? I can't remember if you replaced it or reconditioned it?

Did the new head come with a new pump.

The symptoms do make me think it is a fueling issue and I agree the glow plugs shouldn't matter all that much, even in very cold weather I could get my 1.3 multi to fire if you cranked it long enough.
 
Does it start on starting fluid

Be careful, not to cause a blowback, let the plugs finish their cycle and keep the ignition on
 
It starts on starting fluid. I give it only a sniff but it fires immediately.

The old injection pump leaked. This one is a complete replacement that has just 7000 miles since I installed it on this engine.

The pressure trace rises then levels off sharply and stays there. It looks like it’s being controlled at that pressure.

Before doing this work, the engine had white smoke on start and galloping starter sound. I have replaced the head but the fuel system is unchanged. I even labelled each pressure pipe and injector so they went back as before.

I don’t have a diesel compression tester. But each valve was lapped and “blued” and checked with lupe magnifier. The rockers and lifters were taken from the old head and kept in pairs as they have so few miles.

When it has started there is no smoke and virtually no smell. A massive improvement over the previous head. It sounds very smooth but stalls when you try to rev it. Then no start.

The fuel rail pressure controller and pressure sensor are untouched. Still has the paint seals.

Lift pump in tank runs longer than I’d expect. I clipped some 8mm fuel hose to the filter supply pipe and pegged the open end with a bolt and clip. The pressure nearly pushed out the bolt. Fuel filter element has 7000 miles so I’m assuming it’s ok as engine ran previously.

Crank position sensor looks scruffy (it’s the original). Clutching at straws has me tempted to replace.
Edit. I have just tested the CPS it creates a voltage when you move iron across the face. It’s looking ok.

The original list of fault codes were consistent with air in the fuel system and I had not connected MAF sensor. They all cleared and stayed clear.

P0683 (glow plugs) persists but that’s expected. Plugs are not glowing.
P0180 fuel rail temperature is odd. I cannot see a temperature sensor. It was not on the original list.
I can’t find what D60220 is. It might be a clue.

When it won’t start, fuel pressure does not rise at all. immobiliser icon goes out immediately. Cranking speed sounds good. I jump leaded another good battery in parallel. Starter speed not changed.
 
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In device manager what's the interface called

Screenshot_20240707-195958.png
 
You need diagnostics to read the proper rpm and fuel pressure, I have posted the correct procedure within the last few weeks, and minimum pressure and rpm

It's possible being a small engine, the heat from the compression is soaking away to the atmosphere to quickly to start without glow plugs

Some engines do, some don't, I never tried starting this engine without glow plugs

It's a variable, that needs eliminating.

I probably start here, seeing starter fluid ignition is lower
 
I’ve just ordered the connector/interface shown on the MES Guide.
I sorted the Com 1 error in Device Manager. The interface shows a red LED. Nothing else lights up. MES says cannot communicate with ECU.
I’ll look at the drivers later today.
 
It starts on fluid but won’t continue to run. New glow plugs are on order, but it always started previously (complete with white smoke due to low compression).
 
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It starts on fluid but won’t continue to run. New glow plugs are on order, but it always started previously (complete with white smoke due to low compression).
It does seem like a fueling issue, either injectors not firing or not firing enough ?

the pump on these is on the back of the exhaust cam? is it possible the high pressure pump is 180 degrees out of phase?
Just trying to think of things you could try while you sort out diagnostics?
 
The pump is a three cylinder swash plate type. The drive coupling could be put in two positions but it doesn’t matter because there is no timing at the pump. It’s all done electronically at the injectors.
 
My instincts are that given the pump in tank was powerful at filter when we blocked it, but every time the ignition is turned on the tank pump restarts I suspect somewhere between fuel filter and common rail it is losing that pressure, possibly around the high pressure side Fuel Pressure Regulator allowing pressure to be lost back to tank via return system. As most systems once tank pump has built up line pressure to high pressure pump then tank pump stops or only runs for a short time.
So either dirt or a sticking valve in regulator most likely. I would have said a possible issue with return pipes but it does seem to be intermittent , where as that would be constant.
We did get roughly 260-270 Bar on cranking at around 400Bar plus when it was idling at one point, which I am quite happy is enough pressure for injectors to be triggered via ECU.
When it wasn't starting up Bar reading on MaxiECU was 7Bar, so I tend to think it is a loss of pressure due to mechanical issue rather than electrical.
There was no visible external fuel leaks.
Also once other previous faults cleared the only constant one was the P0683 whether glow plug control unit or just the heater plugs, though voltage from control unit seemed suspect as well as heater plugs not glowing.
Either way I don't believe that issue was the cause of non starting, more the failure to maintain rail pressure.
Can you remove Fuel Rail Pressure valve and Ultrasonically clean it maybe or test it in some way. I know different types are live open or live closed.
The times it did start there was no hint of smoke so I don't think it a compression issue needing easy start, as when running engine sounded fine.:)
 
Is that a terminal error code issue or just a warning, as the only code showing continuous was the P0683 which it did run with?
Terminal who knows

Depends what's causing it, if diesel isn't flowing correctly then yes

Error P0683 and/or P0380 present normally is though, comes under no start under any circumstances,

Fix the obvious bits first then rest often fall into place
 
Terminal who knows

Depends what's causing it, if diesel isn't flowing correctly then yes

Error P0683 and/or P0380 present normally is though, comes under no start under any circumstances,

Fix the obvious bits first then rest often fall into place
Sorry, what I meant was the only code showing related to heater plugs and it was able to run with that.
However if the filter has some kind of flow diversion inside when temp code is showing or even if code not showing but faulty, can it restrict the fuel supply to the high pressure pump by diverting it to return to tank?
It is not a filter design I am familiar with.
I see that filter has one inlet, one supply to high pressure pump and one presumably return to tank to assist with keeping cool fuel flow.
My thoughts are that the problem is lack of a good supply to the high pressure pump, although felt the regulator the most likely area, so curious as to filters job apart from the obvious:)
 
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