Hi all

New to this site and I have a problem. My friend owns a Fiat punto 55 and she recently lost her cam belt on a roundabout. I fixed it for her and timed it in. Started first time and ran well. Smooth as silk and reved nicely. She had a screw in her front wheel so she got that fixed before she took it out but now it won't start. It doesn't even try. It has full bat power, fuel, spark from all four plugs and the timing on the pulley's is still correct. Any suggestions would be appreciated as I don't know where to go from here.

Cheers

is it just turning over or is it 'coughing' and trying to start?

A Dog Is Not Just For Christmas
Sliced Thinly It Can Last Till Easter

sometimes but mostly not which I find strange as I have fuel, spark and apparently at the right time.

if its got fuel and spark the only think i can think off is the valve timing, but if you've got both of the marks in the right place (flywheel pointer & cut out in top pully) then it cant be that.
ive no idea without looking at it, its probly something daft

uno 1.0ie RAAAWW!

My friend is a proper mechanic not a torist like me but even he can't suggest anymore. I will be taking it to his garage at the weekend if I can't sort it. I was hoping that you fiat guys might know of some fatal flaw that I don't know about but I guess not. I still have hope that someone on here can help me figure it out.

best guess i can give is a damaged/loose sensor plug

A Dog Is Not Just For Christmas
Sliced Thinly It Can Last Till Easter

im a proper mechanic too [V]

uno 1.0ie RAAAWW!

did you remove the cam sprocket? little woodruf key didn't get lost, look under oil cap make sure cam is turning, long shot i know but remember someone saying it happened to them once,

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Check the connection & the condition of wiring harness of the TDC sensor & timing sensor

subija

Hi all

Thanks for your replies. Yes I did check the sensor but only by wigling the wires a bit. I'll try something more technical Saturday. I didn't remove the camshaft sprocket though and the cam is definately turning. As I said it ran for a while perfectly fine. Does anyone know how I can test a tdc sensor? Thanks again guys.

you check the RPM/TDC sensor by disconnecting the 3 pin connector and connecting an ohmmeter to the sensor no 1 & no 2 pin. Pin no 3 is the pick-up signal & it is zero reading which produce low voltage (signal)....Resistance 774-946 ohm at 20 deg cel.

Normal problem of this sensor is the three wires are shorted among each other due to heat that melt the coating material of the wire or other symptoms is improper fixing/loosen of the sensor.

Check also the surface of the sensor and the flywheel tooth corresponds to the sum of the length of the sensor (34.5mm) with the gap 0.8 to 1.5 mm order to produce right signal.

Happy sensoring

subija

Thanks mate I'll give that a go
Cheers

Dave