My 2006 1.8TDCi S-max is having trouble start in the cold mornings. Starts ok with temps over 5c but bellow its hit and miss. bellow 0 it takes around 5 starts to reach idle speed. after that it will start every time.

It has new calcium battery, new starter, new glow plugs. also new fuel filter in the last service.

The old starter was bit tired, but had no shavings inside so I would rule out DMF.

The IDS diagnostic does not log any fault codes on PCM. Only strange value I could find in data logger is CylBal_3 value on idle is double to 3 other cylinders. 3 cylinders at 0.6-0.7 and 3rd cylinder is at 1.4. If I'm correct the cylinder 3 in IDS is in fact cylinder 4 due to firing order.

That led me to injectors, so I have done leak off test but all the injectors are leaking back exactly the same amount.

Is there a specific leak off test for siemens injectors?

I have connected test lamp to glow plug wiring, even in sub 0 temps the glow plugs cut out after a second. Could anyone tell me which sensor tells ecu the temperature to activate pre-heat and what controls the duration of the pre-heat. I will take them out to test them on battery, but i'm quite sure they wont get hot within 1s.

I'm trying to exhaust all the cheaper options before having to take out the injectors and have them tested and having compression test done at the same time.

thanks for help

FFS how many times does this get asked....

It's your DMF. Live with it. Unless you have VERY deep pockets.

Most owners don't so just live with it.

FFS how many times does this get asked....

It's your DMF. Live with it. Unless you have VERY deep pockets.

Most owners don't so just live with it.

well thanks, that's very helpful... No shavings in original starter taken out 3 months ago suggest otherwise. Also if DMF was going it would affect starting on warm days too, which it does not. The car has done 130k miles, the compression could be lower so it needs pre-heat when cold.

Why every starting problem has to be DMF related for you?

Update: this morning 2 degrees outside and car decided to pre heat and started fine. Connected test lamp, pre-heat lasted 6-7s as it normally should.

So i'm looking at intermittent pre-heat problem, can anyone please tell me what sensor supplies the temp reading to ecu and where is it located?

It doesn't have to be break up of the DMF that causes the issue so no shavings does not rule it out.

I have a friend who works for ford on engine design and he basically says TDCi plus cold start issues = DMF. Every time.

Go ahead. Waste money on changing this that or the other, you'll come back to the same issue.

I just cant agree with that, saying that every cold start problem=DMF fail is just not right, there are few other options(electrics, fuel, air).

Lets say sticking injector could cause low fuel rail pressure and therefore the injectors will not inject diesel when you turn it over first time.You need to crank it first to build up the pressure.

I do not swap parts just to hope it cures something.

The car does not pre-heat most of the time and I'm trying to cure that. The pre-heat has nothing to do with DMF

I didn't come here to argue, I came here for help

Found the problem, swapped the glow plug wire assy (ford part number 1745678 @ £16). Starting every time, preheats and start first turn.

The black terminal connection inside was loose, causing excess resistance and I found it because there was melted plastic around.

The local ford had it in stock which means its common problem.

If your car is not preheating whatever the temperature have a look at the connection, if the nut will turn with the stud replace it.