Window stops engine!

[Chocolate teaspoon]

I have owned a 2007 1.4 petrol Berlingo van from new. It has done 95000 miles. Mostly trouble-free.
In the last week the engine has stopped several times.
It happens on idle (so far!) and when the engine is hot. Usually hotter than normal due to the weather.
Switching in almost any electrical load, but especially operating the electric windows, causes this to happen.
The revs always drop, but sometimes recover.
When they recover the engine ticks over normally, even if the load is still there. For example, if I switch on the headlights the revs will drop, perhaps to 400rpm, then if they recover everything will be fine with the headlights on until I switch in another load when they will drop again.
It is only the switching in of the electrical load that does it. Perhaps because of the current surge?
The worst offender seems to be the driver's window, when everything seems fine until the window hits bottom and the limit switch opens. At this point the engine revs usually drop below 400rpm and it stops.
It always starts again with no bother.

Is there anything in the electrical system that is supposed to smooth out the voltage? Something that isn't mentioned in any manual I have looked at? Something that isn't working any more?

Otherwise I think there must be a high resistance at a circuit junction/fuse somewhere that is reducing the voltage supplied to the ignition or injection systems, or to the ECU.

But I have no idea where to start. Any advice gratefully received.

[jj9]

I would start by getting the battery checked.

If you have a spare battery or one on a different vehicle try that one on and see if the problem is still there.


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[Chocolate teaspoon]

I would start by getting the battery checked.

If you have a spare battery or one on a different vehicle try that one on and see if the problem is still there.


.

The battery checked out fine, and the problem is still there.
The engine stopped a couple of times last week when I came up to road junctions, so I took it to a garage, and all they could find was an intermittent misfire on No 1 cylinder. This didn't even bring on the orange light, but now it has been pointed out I can feel it (can't think how I missed it before!).
They replaced the plugs, then No 1 injector, but no improvement.
I took the van back to have a think myself, and today when I started it the orange light came on & stayed on.

I borrowed a friend's Launch scanner, which told me there was a problem with No 1, and it was the secondary & primary sides of the coil.
I cancelled the code, and it hasn't reappeared.

If it's one of the coils I don't understand why 2 cylinders aren't affected - No 4 as well, according to the Haynes Manual.

Before I buy a new pack, is it possible for a fault to affect only one cylinder rather than two?

[Tomcat3]

Do you have the coil pack across the top of the plugs or the older separate coil pack and leads? if its the former dont buy the cheapest as these are usually rubbish and faulty from the start or dont last long. Go for a decent make from a reputable supplier. Coil packs on these engines are quite common failures.

[Chocolate teaspoon]

Do you have the coil pack across the top of the plugs or the older separate coil pack and leads? if its the former dont buy the cheapest as these are usually rubbish and faulty from the start or dont last long. Go for a decent make from a reputable supplier. Coil packs on these engines are quite common failures.

I think I have sorted the problem, but not without a lot of faffing.

First the original problem of the idling engine often stopping when the window is opened: I took out the injector rail and put a 9V battery across each injector in turn while blowing into the petrol inlet. Three produced a jet of petrol, but one didn't. This last one only worked when the voltage applied was about 12V.
I replaced it with a new one and cured the problem.
I think that the defective injector was only working intermittently with the full 12V when the engine was running, and any electrical load dropped the voltage momentarily (until the voltage regulator did its stuff) so it stopped working completely for a short time.

Then the misfire on No 1 cylinder that wasn't cured by the garage replacing that injector: the injector they replaced was the one on the far left (the driver's side of my RHD van)) as you open the bonnet. This one was the obvious new one when I got the car back.
But the Haynes manual says that No 1 is at the transmission end of the engine, and this was the one I found to be faulty. So I think the garage replaced a good injector.

The idling is still a bit rough, which I think may be down to the need for new bottom seals on the injectors, as I didn't replace them, but the car runs much better with no misfire felt or shown by the scanner.

But, do I have to pay over £40 for a set of seals????

[Sol]

The injectors have to be coded to the ECU using DiagBox so it (ECU) knows the calibration data for that injector. It may be worth doing now. You enter the numbers on top of the injector for the relevant position. Do the coding, then ignition off and back on again once it tells you too.

[Chocolate teaspoon]

I had not heard of DiagBox, but looking on the internet for info I see that it has been around for some time.
What I can't find is how the connection is made between the device to which it is downloaded and the car.
I assume it has to be done via a code reader, although I can't find a mention of this.
I only have access to a Launch 529 scanner. Can this be used?

[Sol]

No, the kit consists of a Lexia 3 interface and the DiagBox software to go with it. Search eBay for "Lexia 3 full chip" as it comes with the software. This is Citroen factory kit that's been cloned. If you're not pc savvy you may struggle but if confident installing software in windows, and remember it needs to run on a win 7 laptop or notebook, then you'll be fine.

[Sol]

https://www.ebay.co.uk/itm/362696199712

Or even better


https://www.ebay.co.uk/itm/303298936146

[Chocolate teaspoon]

OK, thanks.
I have Windows 10 on my laptop, so I assume it will run on that?