Typical symptoms of crank sensor failure?

[alistairolsen]

So my clio turns over for about 10 seconds before starting, but then always fires up fine, which with other brands I'd attribute to crank sensor failure and starting up on the cam phase sensor.

There is no engine management light on the dash however, would one normally expect this?

If it is a crank sensor fault, I believe there are new and old style crank sensors, can anyone advise which is the best to get?

Thanks

 

[hipwell]

New style has a blue plug and needs the new style harness soldering up which costs about the same as the sensor lol.

As for your problem, not sure, when my crank sensor failed the car wouldn't start at all

 

[Brigsy]

Do you only have the issue in the morning or does it happen every start ?

 

[alistairolsen]

I've just got the car and it has no MOT, so every start so far has been a "morning" cold start

Cheers

 

[Vaughan]

Cam phase sensor? Not on an F4R.

 

[Brigsy]

Might be weak fuel pressure regulator. Click the ign on once and turn off. Click it on again and the the fuel pump will prime, try starting it then and see if it fires straight up.

 

[alistairolsen]

@Brigsy, that worked fine, I assume that means that it's leaking fuel back to to the tank when it's stopped and the excessive cranking is the fuel pump having to build pressure whilst cranking?

Where is the fuel pressure regulator on the F4R? Are they a common failure point?

Thanks

 

[Brigsy]

Yep sounds like regulator fault and need to crank to build pressure up when stood, common issue. Fuel pressure reg is fitted in the sender unit. I believe all you can do is buy a new sender and pump complete, have looked for reg on its own but no joy. Mine does it when sat about for a few days.

 

[alistairolsen]

Is it a returnless system then?

 

[JamesBryan]

Is it a returnless system then?

I think so yeah. Only the Ph1 had a return system i believe.

 

[alistairolsen]

Might just add in inline non return valve then as thats the bit that will have stopped holding pressure.

 

[Brigsy]

Yep returnless setup. I wouldnt bother with non return valve as it will prob just fire up then conk out whilst its sorting itself out

From reading up about it i believe some maps prime the pump every turn of the key (rstuner ?)