Hi to all
I am a newbie,We had a 1.6 elx for 12years until it finally died when the cam belt snapped.We liked it so much because it ticked all the boxes we bought a 1.9 multijet on a 57 plate which runs well do'snt burn oil 55000 miles on clock,but is very reluctant to start on cold mornings,glow plug light flashing.Today I set out to change the glow plugs and decided to change the faulty plugs first in case I ran out of time,after removing the electrics I checked each plug by shorting each plug to the positive terminal of battery to find the duff plugs which I've been told should not spark,In my case they all sparked so I assume they're ok. I have looked on the forum and I read there that modern diesels should start without the assistance of glow plugs,( quite a few posts of no starting problems with a flashing glow plug light) So now I'm a bit confused and am thinking glow plug relay?compression?mixture? can any of you good people give me any pointers or possible solutions, Thanks in advance

Hi mate,

Whilst it was true of the older JTD's etc that didn't really require the glow plugs in the uk climate, the multijets seem to rely on them more.

The test that you have described is a very basic one, and does not test the glow plugs fully. It will reveal if they are drawing current (ie will spark) so would identify a totally dead glow plug, but will not identify one that is tired and not getting fully up to temp in time. In order to test them properly you should check their resistance with a multimeter.

The flashing glow plug light indicates that their is a fault with the pre-heat system. Normally this is just a failed glow plug or two, but don't forget it could also be a preheat control fault. As you say, could be relay etc.

My advice would be to start with testing the resistance of each glow plug, and then go from there.

Alan

if the plugs are still out - then they should actually GLOW when connected to a power source ( battery itself is best),
if back in the car , do several on -off ignition rounds to pre-heat the plugs / upper cylinder before cranking , if it statrts better then it's a plug /control issue,

if no different look elsewhere,
Charlie

Thanks for replies guys( Alan/charlie)the car definitely starts better with several on -off ignition rounds,the colder the weather the more rounds required.I think my way forward now is to check power supply to each glow plug when ignition turned on(I imagine I'm looking for 12volts+)and I need to find a suitable connector block on the wiring harness to do this.Then Check the resistance on each glow plug a(this I'm gonna have to read up on some where)in the forum I hope.
thanks and best regards george

Can't you just disconnect the plugs from the harness, then put a multimeter across them (i.e on the end connection and the cylinder head) and check their resistances? Anything showing open resistance (infinite ohms) is past it, as is one that shows a complete short. I think the correct value is around 1 ohm.

It might also be worth having a look at this:

https://www.fiatforum.com/stilo-guides/151734-dealing-preheat-fault-message-stilo-jtd.html

Hi to the widemouthfrog
I looked on you tube and that is one way of checking the glow plugs, at the same time I can then check the voltage between the disconnected plug cap and the engine block for the first few seconds after the ignition is turned on.I need to buy a suitable pair of long nosed pliers to make replacing the plug caps back onto the glow plugs a bit less of a fiddle
regards and thanks, george

with my older FIAT diesels,
I used to replace the sets of plugs every couple of years,
having ZERO electrical knowledge - I just tested them on a battery,
they would ALL glow well..,
so I assumed it was cruddy connections on the "busbar" the older engines used,
now the JTD is a MUCH better design ( apart from access!!) with individual cables to each plug - and the plugs aren't on the front of the block - getting doused in road salt everyday,
Charlie