Car problem - I need a diagnostic please

Drexl Spivey

Hi,

I have a Renault Megane classic - 1998 - 88 000 miles.

The car works a charm. But now and again, for no apparent reason, the car will not start. I can still hear the ignition, but it won't start.

At that point, there is a flashing light on the dashboard.

It acts like if there was no petrol in the tank, but there is.

It happened to me 3 times. If I add petrol to the tank, then the car will start.

I was thinking of dust in the tank ...

Can anyone tell me what could be the cause of this please?

crosstownk

What does the flashing light look like?

BrianD3

The flashing light could be the immobiliser light and the symptoms (except for the starting after you put petrol in) also sound like they could be immobiliser related. I presume you you are aware of the immobiliser "quirk" in this car - if you unlock the car and don't start it within a few seconds the immobiliser will activate and you will need to lock and unlock it again with the plip key to start it.

Darragh29

Jeff Bond wrote:

Hi,


I was thinking of dust in the tank ...

Very unlikely to be this. Is the problem just when you are starting the engine or does the engine ever cut out when it is running???

stratos

If it looks like a duck walks like a duck well its probably a ........

If adding petrol gets the car started and it behaves like its out of petrol well it probably is out of..........

the fuel gauge or sender may be faulty.

crosstownk

stratos wrote:

If it looks like a duck walks like a duck well its probably a ........

RENAULT*














*Sorry - couldn't resist............

Drexl Spivey

Thank you all:

Stratos:
The tank is not empty, I can fill it up with 20e. If it was empty, I could put 50.

Darragh29:
It never happens while running.


BrianD3:

I was not aware of an immobiliser thingie. It looks like that could be it!


CrosstownK:
The flashing light looks like a circle.
Every other light has a symbol (battery, lights, warning, ...) but this one is just a circle.

BrianD3

The flashing circular light is definitely the immobiliser light. If you leave the car too long before starting it after unlocking it, the light will flash and the starter will turn the engine but it won't fire. This is normal behaviour for the Megane I phase 1.

daedalus2097

Yep, the immobiliser cuts power to the fuel pump, meaning it will indeed act as if it's out of petrol. I'd say you're eager to test it after you put the petrol in and so you try it much quicker than you would normally, thus beating the immobiliser timeout... Hope that's all it is anyway, cos if it's not, it'll be an awful problem to find...

Mr.Diagnostic

I would suggest that the OP should check out how the immob light works when the car does start. Then see how it behaves when it fails to start.

Common faults inc. faulty key which can be repaired and the key receiver (aerial) suffering water ingress.

Drexl Spivey

Gentlemen,

Thank you all for your help, especially Brian.

I'm almost sure that's it now. I will try to reproduce the problem to make sure (once I am at home).

I love Boards!

kittex

Yay for boards indeedl!
I just bought my first car, a 1998 Megane and have been having this exact problem. Exact same symptoms, same little round light, acts as if there's no petrol etc

As a new driver, I am taking ages to get myself organised in the car, fussing about with things, so must be leaving the immobiliser to kick in.
It eventually started but in hindsight, I had locked and unlocked the doors again at that stage.

I shall try this later. Fabulous.

Edit: Forgot to say thank you for the fix Brian and co.

crosstownk

Does the same fault occur if you use the spare key instead?

RedLemon

I have the same problem with my Renault clio 2000,
it won't start , and I sent it to the garage, it starts!!! they said it's the immobiliser, normally set on/off almarm/immobiliser will solve the problem,

but sometimes , i have to do that more than 10 times!!! i think the battery will be my next problem if do this again and agian :mad: