Technical Not starting when hot

[KSD]

Evening All

I have a 2017 Fiat Tipo 1.6 Mjet Diesel and I'm having bad trouble starting the car when it's hot.
No fault codes present in the ECU memory and it starts normally when cold. I have changed the crankshaft sensor today as experience of other vehicles have this issue when hot.

I've been a technician for over 20 years with Fiat main dealer experience also, but without any sort of indication or fault code it's a bit difficult to fathom out.
It started doing this after the spill pipe on injector no.2 burst and leaked on the way to work one morning about 2 months ago. But I haven't checked the injectors yet for leak back quantity which I will do over the weekend. But it doesn't seem to be an injector issue.
Any help would be greatly appreciated

 

[KSD]

Just a quick update,
Done a leak back check on the Injectors and it showed up that 3 of the 4 were spilling back excessively.
So I have changed them and coded them into the car, but it still having starting issues when hot but only when hot. Still no fault codes either.
I have checked the lift pump under the back seat and it seems to have plenty of pressure in it.
When it's cold and it's running I cannot fault the car drives perfect, but as soon as I stop the car when the engine is hot it will not start again. Could this be a shut of valve in the main injection pump!

Any ideas please

 

[chris3234]

Just a quick update,
Done a leak back check on the Injectors and it showed up that 3 of the 4 were spilling back excessively.
So I have changed them and coded them into the car, but it still having starting issues when hot but only when hot. Still no fault codes either.
I have checked the lift pump under the back seat and it seems to have plenty of pressure in it.
When it's cold and it's running I cannot fault the car drives perfect, but as soon as I stop the car when the engine is hot it will not start again. Could this be a shut of valve in the main injection pump!

Any ideas please

What do the fuel pressures look like before starting and during cranking this should show if it's a possible fuel issues

 

[KSD]

Fuel pressure is irrattic during cranking from hot, it can go from 2.0 to -2.0 MPa,

 

[varesecrazy]

Failing pump..

Or pressure bleeding off ?

On the old 1248's people have had bleed off problems

 

[KSD]

When the engine is running, it runs without fault. It just struggles to start when the engine is Hot. I noticed that the car seems to start a little better with the return/spill pipe clamped off. But still not as it should be.
I'm going to get it plugged into WiTech tomorrow to see if this flags up anything other than the normal diagnostic machines can see.
I'll keep you posted.

 

[caoc9]

When the engine is running, it runs without fault. It just struggles to start when the engine is Hot. I noticed that the car seems to start a little better with the return/spill pipe clamped off. But still not as it should be.
I'm going to get it plugged into WiTech tomorrow to see if this flags up anything other than the normal diagnostic machines can see.
I'll keep you posted.

Hi KSD
Did you fix the problem? I have a similar problem, but with a Twinair motor. Not the same, but maybe you solution could apply to mein...
Regards

Per