Technical No start

[Punto Pro]

Hi FIAT people
1.3Mjet 2007 Manual
Engine just cut off diesel while driving and I want it back on rails ASAP
Please help !
Symptoms:
- Key in first position dash lights up, no fuelpump buzz, key in start position , no turn over, right after key back to zero. Then again key to first fuelpump buzz, engine turns over fine.
But no start.
- coils on injetornozzles hum, chatters like digitally sound all four, in first key position.

? What have been done ?

- All ground connections cleaned
- ECU off mount and connections to ground cleaned
- newish fuelfilter (2mounths)
- feed fuelpump gives sufficient fuel at 2bar+ /12Vdc
- no air in fuellines and these are tight
- fuelvalve at rail interchanged
- fuelpressure sensor at fuelrail shows 306bar at 350rpm, cranked with starter.
- injectornozzles returnbleed seems little of amound but are messured equal
- EGR valve is checked shut
- when starter goes for 15 sec. it smells of unburned fuel from exhaust
- it runs fine on brake cleaner
- Fusebox have been disassembled , all fuses checked, big connections underneath have been checked too.
- fuel relay works fine when it gets the signal
- accumulator/battery interchanged
- ECU reset over night without power
- fuelcutoff button pushed
- inductive cam lube count Ohm 784
- inductive Crank/flywheel count Ohm 780, but replaced with new.
- start attemted with my 4 keys
- no fault codes
- freash 15L of diesel in tank

 

[bugsymike]

I see you have checked the fuel pump relay, but this is what we had.
May be unrelated but had this with daughters 06 Grande Punto:- No fuel pump buzz in tank and no starter motor operation, powered up the relay for fuel pump at fusebox under bonnet , car then started and ran.
Cause was the trigger feed from the ECU to operate the relay.
The signal feed from the ECU pinout was good, but the wire a few cm from the ECU had rotted through!
I bought the car as a non runner as the previous owners mechanic had dragged it around on a tow rope trying to start it and broke the timing chain!
So after fixing the chain I then had to find the cause of the original non starting, which was as I have mentioned above.

 

[Punto Pro]

I see you have checked the fuel pump relay, but this is what we had.
May be unrelated but had this with daughters 06 Grande Punto:- No fuel pump buzz in tank and no starter motor operation, powered up the relay for fuel pump at fusebox under bonnet , car then started and ran.
Cause was the trigger feed from the ECU to operate the relay.
The signal feed from the ECU pinout was good, but the wire a few cm from the ECU had rotted through!
I bought the car as a non runner as the previous owners mechanic had dragged it around on a tow rope trying to start it and broke the timing chain!
So after fixing the chain I then had to find the cause of the original non starting, which was as I have mentioned above.

Thnx ! Input is sorely appreciated.
I am surely going to check wireing around.
While the issue it is not running the symptom is, engine is only turning over, every second time the key is turned. So could be wireing though, if current needs to build up to pass resistance/damaged wireing signal 86 on relay, this then happens the second time key is turned.
So I tried to bypass pumperely with wire from 30 to 87 relaypin, to run feed pump continiously while testing pump voltage and pressure ( 2bar× @12Vdc) ,on analog manometer, for 30min. This continiously feed of fuel cycle, was also, to ensure all air was bled out. I've tried last night to let it run for a 2-3 minutes on brake cleaner, and it sound surpriceingly fine, so I thourght now its running, but no reation from accellerator, so no diesel. This is strange because when i turn engine for 15sec. or so, it smells of fuel fumes from exhaust.
Would there be a wrong timing from nozzels ?
Be with fuel in exhaust it would surely fire up cylinders ?
Wrong valve timing ? Then it would run nice on brake cleaner.
AFM ?
I need to check Crank timing sensor wireing to.
Its also weird about the current noise from injector coils, only present with key in sec. position.

 

[bugsymike]

Seem to recall used powered and fused test probe from battery straight to 87 on at fusebox, make sure fused though .
When running on brake cleaner etc. it can't really be "fine" as fuel would ignite when enough compression and not at correct timing position via injection and ECU triggering it. So in other words it is being forced to run and not happy, very harsh.
Re the intermittant cranking of the starter, if fuel relay removed will it crank at all? Just to see if it is the same setup as my daughters one was.

 

[Punto Pro]

Seem to recall used powered and fused test probe from battery straight to 87 on at fusebox, make sure fused though .
When running on brake cleaner etc. it can't really be "fine" as fuel would ignite when enough compression and not at correct timing position via injection and ECU triggering it. So in other words it is being forced to run and not happy, very harsh.
Re the intermittant cranking of the starter, if fuel relay removed will it crank at all? Just to see if it is the same setup as my daughters one was.

Hi , thank you for input !
Yea, it cranks fine without the fuel pump relay.
So today I got ECU , ECM , transponder and key from chopshop, installed it all and it cranks fine , all same as before. No startup of engine..

 

[bugsymike]

So exact same faults with different ecu etc.?
I know you did a leak test on injectors, any chance a duff injector leaking into engine, with common rail system if one injector faulty even, none will function.
If you are going all out!!! pull out all injectors , do a proper compression test whilst out then refit injectors to fuel rail and crank engine to see if injectors spraying.
BEWARE THIS IS DANGEROUS AS INJECTOR SPRAY MIST IS EXTREMELY HIGH PRESSURE AND CAN GO RIGHT THROUGH YOUR FINGER OR WHAT EVER PART OF YOUR BODY GETS IN THE WAY!!!!! When at college 50 years ago when diesel pump pressure was much lower the "mist" could punch a hole through a sheet of paper when held up to the light!!! So easily a hospital job if careless!!!
Safest is to take the injectors to a diesel specialist to test them for you.
Important if you take injectors out mark them clearly so you refit them in their original cylinders.

 

[Punto Pro]

So exact same faults with different ecu etc.?
I know you did a leak test on injectors, any chance a duff injector leaking into engine, with common rail system if one injector faulty even, none will function.
If you are going all out!!! pull out all injectors , do a proper compression test whilst out then refit injectors to fuel rail and crank engine to see if injectors spraying.
BEWARE THIS IS DANGEROUS AS INJECTOR SPRAY MIST IS EXTREMELY HIGH PRESSURE AND CAN GO RIGHT THROUGH YOUR FINGER OR WHAT EVER PART OF YOUR BODY GETS IN THE WAY!!!!! When at college 50 years ago when diesel pump pressure was much lower the "mist" could punch a hole through a sheet of paper when held up to the light!!! So easily a hospital job if careless!!!
Safest is to take the injectors to a diesel specialist to test them for you.
Important if you take injectors out mark them clearly so you refit them in their original cylinders.

Hi
Surely there can a spraypattern issues on top, but would it cause the key / feedpump preload issue ?
I know a few diesel workshops that can do a complete injector job.
Yes, a all Punto's management systems is replaced.
So i guess is all about wireing know.
Any suggestions where to begin ?
I have no overview over PINS or schmatics or diagrams at all.
Thanks !!

 

[bugsymike]

Hi
Surely there can a spraypattern issues on top, but would it cause the key / feedpump preload issue ?
I know a few diesel workshops that can do a complete injector job.
Yes, a all Punto's management systems is replaced.
So i guess is all about wireing know.
Any suggestions where to begin ?
I have no overview over PINS or schmatics or diagrams at all.
Thanks !!

I wasn't thinking so much about the quality of spray pattern , but more of a faulty injector releasing line pressure so the whole system wouldn't have sufficient pressure for the ECU to activate injection in the first place. So there would be more of a "dribble" from the nozzle on one injector.
The "leak off test" will show leak via the low pressure return, I was thinking more along the line of a leak into the cylinder. Is the engine oil level higher than normal or smell of diesel?
I was throwing a few odd suggestions into the mix as you have tried most of the likely ones.
I don't have any pinouts or wiring diagrams, hopefully someone else on Forum does.

 

[Punto Pro]

Fuse box failure!

 

[Punto Pro]

I wasn't thinking so much about the quality of spray pattern , but more of a faulty injector releasing line pressure so the whole system wouldn't have sufficient pressure for the ECU to activate injection in the first place. So there would be more of a "dribble" from the nozzle on one injector.
The "leak off test" will show leak via the low pressure return, I was thinking more along the line of a leak into the cylinder. Is the engine oil level higher than normal or smell of diesel?
I was throwing a few odd suggestions into the mix as you have tried most of the likely ones.
I don't have any pinouts or wiring diagrams, hopefully someone else on Forum does.

Hi
Thank you for advice and help.
Punto Pro is flying again !