Technical Intermittent starting

[Benscott]

I have an issue with my ducato
2002 motorhome 2.8jtd
It has an intermittent starting problem
Engine turns but won’t fire up
Then the next minute it’s perfect
I had the ecu re programmed to remove the imobiliser to a free run ecu as that’s what I was advised to do but still have the same intermittent starting problem
Was told it cool be a relay under fuse box but I don’t know what all the relays do
Any help would be greatly received
Picture of relays if anyone can help identiy any
Thanks

 

[Communicator]

Hi Ben.

At the top of the post entry window, there ia a capital letter 'B'. If this button is pressed inadvertantly, your post will all be in bold typeface. This can be corrected by marking the relevant text and then pressing the 'B' button.

After a many years of working with relays, I tend to be sceptical when relays are blamed for faults, but perhaps this is because they are easy to eliminate, however poor connections to the relay can also cause problems. Unfortunately there is a lack of published electrical information relating to your x230 2.8jtd

If I understand correctly, your emgine sometimes cranks OK, but is reluctant to start, then once started runs OK. This does not sound like a relay problem. Have you considered the camshaft sensor? On the 2.8jtd the camshaft sensor is only used when starting, to determine the stroke, with all subsequent timing being taken from the crankshaft sensor.

If you wish to identify the relays for your present, and any future problem perhaps a "pull and see" approach may work. To do this you will need to pull a relay, and than with ignition on, attempt to find what does not work.

For a start the blue relay in your picture is the probably direction indicator/emergency flasher.
I have seen used versions of the yellow relay descibed as a "comfort module" which means the seller does not know its function. I suspect that it contains an electronic timer and/or an end of travel current operated trip circuit, e.g. for windows.

Other functions using relays on pre 2000 x230s are:-

Dipped headlghts
Main beam headlights
Starter (diagrams for pre 2000 x230 show this)
Heater fan
Heated rear window (probably not on a MH).

The above are probably the grey coloured relays in your picture, then also.

Electric cab windows if fitted
Horn is commonly controlled via a relay, but may not be on x230.
Cooling fans?
The above list does not include relays directly associated with the 2.8jtd engine, which on my x244 are:-

Main injection relay
Fuel pump relay
Diesel heater relay
Flame starter valve relay
(On the x244 these four relays are housed with other essential relays in an engine bay fusebox.)
Also separately in the engine bay is a larger relay for the flame starter glowplug.
Please note that the flame starter is only used below about zero centigrade.

 

[Benscott]

Hi Ben.

At the top of the post entry window, there ia a capital letter 'B'. If this button is pressed inadvertantly, your post will all be in bold typeface. This can be corrected by marking the relevant text and then pressing the 'B' button.

After a many years of working with relays, I tend to be sceptical when relays are blamed for faults, but perhaps this is because they are easy to eliminate, however poor connections to the relay can also cause problems. Unfortunately there is a lack of published electrical information relating to your x230 2.8jtd

If I understand correctly, your emgine sometimes cranks OK, but is reluctant to start, then once started runs OK. This does not sound like a relay problem. Have you considered the camshaft sensor? On the 2.8jtd the camshaft sensor is only used when starting, to determine the stroke, with all subsequent timing being taken from the crankshaft sensor.

If you wish to identify the relays for your present, and any future problem perhaps a "pull and see" approach may work. To do this you will need to pull a relay, and than with ignition on, attempt to find what does not work.

For a start the blue relay in your picture is the probably direction indicator/emergency flasher.
I have seen used versions of the yellow relay descibed as a "comfort module" which means the seller does not know its function. I suspect that it contains an electronic timer and/or an end of travel current operated trip circuit, e.g. for windows.

Other functions using relays on pre 2000 x230s are:-

Dipped headlghts
Main beam headlights
Starter (diagrams for pre 2000 x230 show this)
Heater fan
Heated rear window (probably not on a MH).

The above are probably the grey coloured relays in your picture, then also.

Electric cab windows if fitted
Horn is commonly controlled via a relay, but may not be on x230.
Cooling fans?
The above list does not include relays directly associated with the 2.8jtd engine, which on my x244 are:-

Main injection relay
Fuel pump relay
Diesel heater relay
Flame starter valve relay
(On the x244 these four relays are housed with other essential relays in an engine bay fusebox.)
Also separately in the engine bay is a larger relay for the flame starter glowplug.
Please note that the flame starter is only used below about zero centigrade.

Is there a way of checking camshaft sensor ???
But yes turns over perfect but only fires up every 10th turn
Once started runs like a dream

 

[Communicator]

Possibly via Multiecuscan, or by substitution. Adjustment is critical, and I remember reading about problems with incorrect spacing on some engines, when new. T think that Fiat supplied special packing washers for a recall. Perhaps a forum ao internet search would reveal something?

See attached extract from x244 eLearn for description and adjustment details.

 

[Benscott]

Possibly via Multiecuscan, or by substitution. Adjustment is critical, and I remember reading about problems with incorrect spacing on some engines, when new. T think that Fiat supplied special packing washers for a recall. Perhaps a forum ao internet search would reveal something?

See attached extract from x244 eLearn for description and adjustment details.

Would this stop it starting 1 in 10 then when running runs perfect

 

[Communicator]

A failure rate of 1 in 10 seems very precise, or is that just a figure of speech? All that can be said is that a failing or badly adjusted camshaft sensor could be the cause of you problems. Given the age of your vehicle, the cambelt should have been replaced several times. It is possible that the sensor may have been disturbed during these operations.

 

[Benscott]

A failure rate of 1 in 10 seems very precise, or is that just a figure of speech? All that can be said is that a failing or badly adjusted camshaft sensor could be the cause of you problems. Given the age of your vehicle, the cambelt should have been replaced several times. It is possible that the sensor may have been disturbed during these operations.

Thank you I will get to have a look

 

[Benscott]

Thank you I will get to have a look

I’m thinking the relay circled is faulty
On 1st start it makes 2 clicks and starts straight away
After 1st start it only clicks once then turns over but won’t start
Would anyone know what this relay is

 

[Communicator]

I cannot help with the function of the relay, but as to being faulty that is not proven. Have you monitored the 12V supply to the relay coil?
The relay is quite possibly responding to the signal applied to its coil. The relay is a 20A Normally Open (N/O) micro automotive relay, and is likely to have a surge absorbing resistor internally connected across the coil.

When starting power is of course supplied by the battery, and all equipment earthed to chassis which includes the ECU, will have to return current to the battery via this earth point.

Given the age of the vehicle, it will be wise to inspect the condition of the main chassis earth point situated on the RH inner wing, and forward of the engine mounting. While not as notorious as the x250 earth strap, internal corrosion of the flag terminal has been reported. See attached photos of good and poor condition main earth points.

 

[Benscott]

I cannot help with the function of the relay, but as to being faulty that is not proven. Have you monitored the 12V supply to the relay coil?
The relay is quite possibly responding to the signal applied to its coil. The relay is a 20A Normally Open (N/O) micro automotive relay, and is likely to have a surge absorbing resistor internally connected across the coil.

When starting power is of course supplied by the battery, and all equipment earthed to chassis which includes the ECU, will have to return current to the battery via this earth point.

Given the age of the vehicle, it will be wise to inspect the condition of the main chassis earth point situated on the RH inner wing, and forward of the engine mounting. While not as notorious as the x250 earth strap, internal corrosion of the flag terminal has been reported. See attached photos of good and poor condition main earth points.

 

[Benscott]

Thank you so much for your reply
My earth strap is Definately rusty
I will runn a new earth tomorrow

Thanks for all the advice