Hi,

For the past 2 or 3 years it my Doblo1.9 Multijet 2006 has developed a starting problem when left for 2 hours.

It always starts first time when the engine is cold, whatever the weather. BUT....when I go to start it an hour or so after doing a short journey, it doesn't start as well and needs a couple or three attempts.

It's puzzling as generally the car runs really well, I've cleaned the EGR, replaced the crank sensor and checked the earth strap is making good contact, but, I've also read that it's a common problem which one has to live with.

Can anyone help me fix this, any advice is much appreciated.

Thanks

Ron.

I posted a similar message on the Doblo forum but I haven't received any replies.

Does it crank for ages when trying to start?
Could be loosing pressure from the injection system from excessive injectors leak back or drawing in air from other parts of the system

Hi,

Thanks.

At cold start it fires up after turning over a few times, so when it doesn't start (after the couple of hours) I tend to let it crank over the same as when cold, if it doesn't fire up then I switch it off and then immediately have another go. Letting it crank over for longer doesn't make it start sooner.

So how to I test the injectors or find leaks? Can multiecuscan help with this?

Cheers

Ron

Injector leak off test would show if they are leaking excessively

Also you should be able to monitor the fuel rail pressure using Mrs both when the car has been sat for while and when the engine is running to compare the two values
Shouldn't be massive difference between then two I'd think

Edit just read first post again you said it starts fine when it's been sat overnight or longer periods so less likely to be a fuel pressure issues as it would also drop very low after this length of time if the engines still warm when trying to restart could be a sensor issue caused by the heat?

Pull the glow plugs and check all are in good condtition.

Rig up a temporary bypass wire and switch for the glow plugs. If it starts better with that, you need to check the glow plug controller is cutting in soon enough.

A long shot - how old is the fuel filter cartridge?

Hi,

Thanks.

I've had a reply on the Doblo forum. Suggestion is that it could be temperature related. My plan (over the weekend) is to measure various temperatures (engine atmospheric etc) with Multiecuscan and an IR thermometer and see if there any any obvious inconsistencies.

I'm thinking water temperature sensor on the blink, does this happen?

Cheers

Ron

Water temperature sensor could cause problems but I think it's more likely to affect petrols than diesels. At low temperature the petrol ECU ignores the O2 sensor so the mixture runs rich. It corrects when the O2 sensors signal cuts in as temperature rises.

Diesels probably use the same low temp reading to trigger the glow plugs but a faulty low reading would over-use the plugs rather than the opposite.

My temporary wire suggestion is to see it the engine starts ok when direct power is used on the glow plugs. If it does, the glow plug control circuit is in the frame.

Thanks, I think I get it.

About 2 years ago the local dealership replaced 2 glowplugs that had gone down after the warning light came on. I'll test it as you suggested.

Thanks

Ron