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Fiat Panda 1.2 MPi 2005 - Intermittent non start - Fixed #

Posted by James Mccallum on October 14, 2012, 8:20 pm

Year of Manufacture *: 2005
Engine Size and Code *: 1242
( Optional ) Scanner Used: Sykes
( Optional) Fault Codes: None

Hi everyone, intermitent non start. Seems to be getting worse.
No injector switching
Doesnt always prime.
Tested CKP gives good signal.
Fuel pump relay clicks, swapped relay to check operation.
Main relay does not provide supply to injectors, coil or CMP, if I bridge relay supply present but still no start. Relay is ok and ECU is switching to earth, tested with noid light.
No continuity to fuel pump from battery earth, not sure where inertia switch is.
The car is intermittent non start so cant see how it could be inertia.

If I give supply from main by bridging why is voltage present but not when relay in position?
Wiring must be intact.
I swapped main relay to remove from equation.
Am i missing something here?
TIA
James

Re: Fiat Panda 1.2 MPI Intermittent non start

Posted by lee mackintosh <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1348' width='330' height='300' border=0 style='border:none;'> on October 14, 2012, 9:32 pm, in reply to "Fiat Panda 1.2 MPI Intermittent non start"
Lee Mackintosh

Is this the engine with ecu on throttle body, if so I'd double check the earth ring terminal as they are a common failure or add your own.

Re: Fiat Panda 1.2 MPI Intermittent non start

Posted by James Eardley <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3143' width='330' height='300' border=0 style='border:none;'> on October 15, 2012, 12:25 am, in reply to "Fiat Panda 1.2 MPI Intermittent non start"

Hi James

Are you checking the crank signal at the ecu?

Voltage drop testing should be used to varify relays and connected circuits.

'If I give supply from main by bridging why is voltage present but not when relay in position?
Wiring must be intact.
I swapped main relay to remove from equation.
Am i missing something here?'

Im not sure exactly what you are saying here (Im tired)

If I have read it correctly I would be checking the control side of the relay

hth
James

Re: Fiat Panda 1.2 MPI Intermittent non start

Posted by james mccallum <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat5583' width='330' height='300' border=0 style='border:none;'> on October 15, 2012, 10:27 pm, in reply to "Re: Fiat Panda 1.2 MPI Intermittent non start"
James McCallum

Hi James, sorry your tired.

I checked output from crank sensor but not at ecu.
I checked for voltage at injectors, there was none so I bridged relay and voltage appeared.
I swapped relay but no difference.
I checked Relay switching using noid light and also using multimeter, it switched ok.
The pump sometimes primes and somwetimes does not, but the intermitent starting does not seem to relate to priming.
I tested continuity to fuel pump, it does not seem to have any so I wanted to know where inertia switch was, to eliminate from my investigation.
I wanted to know why injectors are not getting frrd, static and cranking and yet all components seem to be working as they should. Hence, What am I missing?
Thanks in advance James

Re: Fiat Panda 1.2 MPI Intermittent non start

Posted by James Eardley <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3143' width='330' height='300' border=0 style='border:none;'> on October 16, 2012, 7:45 pm, in reply to "Re: Fiat Panda 1.2 MPI Intermittent non start"

Hi James

'I checked for voltage at injectors, there was none so I bridged relay and voltage appeared.
I swapped relay but no difference.
I checked Relay switching using noid light and also using multimeter, it switched ok.'

What happens if you ground the relay control curcuit manually?

'I tested continuity to fuel pump, it does not seem to have any so I wanted to know where inertia switch was, to eliminate from my investigation.'

Is there no continuity just when the car doesn't start or all the time?

According to autodata the switch is near the passenger kick panel.

What is the fuel pressure when the vehicle will not start?

'Main relay does not provide supply to injectors, coil or CMP,'

My diagram says,

The main (K46/EC) relay feeds power to:

EVAP and front and rear o2 heaters and A/C relay via fuse 11.

All injectors and both coils via fuse 17.

The fuel pump via fuse 22

The CMP recieves its power direct from the ECU!

If you have got power to all these components and not the injectors and coils, have you got power at both sides of fuse 17?

Have you got power at pin D12 of the engine bay fuse box light blue/yellow wire?

Then there is also a connector before both the injectors and coils.

I would expect some fault codes?

hth
James

Re: Fiat Panda 1.2 MPI Intermittent non start

Posted by james McCallum <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat5583' width='330' height='300' border=0 style='border:none;'> on October 16, 2012, 8:17 pm, in reply to "Re: Fiat Panda 1.2 MPI Intermittent non start"
James McCallum

Hi James thanks for all that. Very thorough. I will be looking at it again this weekend. Thanks again
James

Fixed #

Posted by James McCallum on October 20, 2012, 7:50 pm, in reply to "Re: Fiat Panda 1.2 MPI Intermittent non start"
Message modified by board administrator October 22, 2012, 7:38 pm

Hi, did full system check, missing supply to ecu causing problem. Didnt realise that that would stop rev counter moving when cranking.
Thanks for any help James

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