Technical Starting problem when warm.

[Poperon]

Hi,

For the past 2 or 3 years it (1.9 Multijet, 2006) has developed a starting problem when warm.

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 of attempts.

It's puzzling as generally the car runs really well, I've cleaned the EGR and replaced the crank sensor 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

 

[Poperon]

Hi,

I'm still puzzling this one but no joy in finding out what is causing it.

A bad connection of the earth strap is often mentioned as causing this sort of problem, so I took out the battery and had a good prod at where it bolts to the bodywork and gearbox. All looks good. As a double check I connected a 10mm² cable from the battery to the engine casting and took it for a drive, it made no difference.

Any ideas much appreciated

Ron

 

[varesecrazy]

What temps are the sensors reporting at restart?

If it thinks its stone cold.. ( but is actally still warm) it may be overfuelling

 

[Poperon]

Hi,

Now that sounds a possibility, I had noticed on a couple of occasions a puff of light grey smoke from the exhaust after it was doing it's difficult to start thing. Would that also be a sign of overfuelling?

I see on Multiecuscan it records air temperature, fuel temperature and engine temperature. Presumably the suspect one is engine temperature and it should read about the same as the temperature of the block (which I could measure with an IR thermometer)?

Cheers

Ron

 

[varesecrazy]

More like 2 sensors showing 16'c

And the other showing -20'c..

 

[geegee123]

Having the same problem with mine-sometimes starts A-OK, randomly takes really long to turn over.

Have replaced Crank sensor too, no difference. Temp sensor sounds a good shout....

Any other hints would be welcome !

 

[geddy1972]

has anyone got any updates on this as mine is now doing exactly the same.

its a 57 plate 1.9 multijet aswell.

i bet if its the temp sensor then it has to be hidden and will involve taking half the engine apart !

 

[geddy1972]

also if the temp sender is playing up will this effect the reading on the temp gauge ?

i can only find one sender on the fiat EPC in the back of the thermostat housing.

 

[Poperon]

Hi,
I don't think it's the temperature sensor, I replaced mine recently and problem still there. Baffling.....
Cheers
Ron

 

[geddy1972]

Hi,
I don't think it's the temperature sensor, I replaced mine recently and problem still there. Baffling.....
Cheers
Ron

thats one thing off my list then.

my other thoughts are fuel pressure sender, crank sensor and camshaft sensor.

i hope its not cam sensor as thats hidden behind the cambelt and i would need to get a garage to do that.

crank sensor seems an easy job.

fuel pressure sensor doesnt seem too bad either.

trouble is im not sure any of them is the problem !

 

[geddy1972]

just been chatting to my workshop guys and they think it could be a crankshaft sensor or map sensor.

i work at a volvo penta marine engine main dealer and they work on big 6cyl diesel engines and they use their vodia machine things to look at temp readings from senders.

also if the engine takes longer to start then the crank sender could be at fault as the ecu reads the camshaft sender and the cam spins at half the speed of the crank.

need to load ecumultiscan onto my laptop and see ifi can use that to diagnose the problem.

 

[Poperon]

Hi,
Well, if it helps.....
Replaced the crank sensor, camshaft sensor (same time as cambelt change) and MAP sensor....problem still there. Totally baffling!!
Also replaced the diesel high pressure regulator (on the pump)....same result.
@geddy1972 what is the fuel pressure sender?
Hopefully we can get to the bottom of this problem (b**** nuisance).
Cheers
Ron

 

[geddy1972]

Hi,
Well, if it helps.....
Replaced the crank sensor, camshaft sensor (same time as cambelt change) and MAP sensor....problem still there. Totally baffling!!
Also replaced the diesel high pressure regulator (on the pump)....same result.
@geddy1972 what is the fuel pressure sender?
Hopefully we can get to the bottom of this problem (b**** nuisance).
Cheers
Ron

the fuel pressure sensor sits in the end of the fuel rail that feeds the injectors.

they are electronically controlled (common rail) type of system.

I wont bother changing all those other sensors now, thanks for the advice.

might have to take it to Dean at small car services near where i live. he is ex fiat Mechanic and used to work at the same place as me when i was a parts manager at a fiat dealership in swanwick hampshire.

i got him to solve a limp mode, cutting out problem and to do my cambelt.

Small Car Services

smallcarservices.co.uk

 

[Poperon]

Hi,
I did check out fuel pressure on MES a few times recently, the "Fuel pressure" and "Desired fuel pressure" were pretty much in sync.
Cheers
Ron

 

[geddy1972]

can i do this using the free version of the MES or do i need the licence ?

 

[Poperon]

can i do this using the free version of the MES or do i need the licence ?

I'll guess, yes but possibly check it out on their website.
Ron

 

[geddy1972]

Managed to run the latest version of the multiscanecu and it's given me an error code.

Not sure if it helps as I have been getting a glow plug failure warning as well.

The code is P0683 preheating control unit (feedback) signal low.

Error details...
Engine temp 23.7 c
Engine speed 828 rpm
Fuel quantity 15.0 mm3/l
Gas pedal position 0.00 %
Fuel pressure 5990 psi
Boost pressure 15.49 psi.

Also the engine temp reading was something like -299 degrees !

If the temp sender is faulty is it causing the glow plug problem and the starting issue.

Took 6 trys this morning to start.

Once warm it seems ok.

Think it only plays up when the weather is warm.

Any ideas anyone ?