Why do Micra's flood?

[BristolBoy]

For the first time ever since owning my K11 Micra, I left it parked facing downhill over the Christmas break (5 days). When I tried to start it today, it refused and seemed to be flooded. A quick look on this forum suggested that this is quite a common problem.

I got it started by pulling the fuel pump fuse and spinning the engine to clear the cylinders, but it left me wondering why this should happen. I vaguely recall someone else having the same problem due to their car being parked facing downhill, but I can't remember what they said the problem was.

Obviously this can't be a problem which has been there since the car was new, otherwise Nissan wouldn't have sold many K11's. So does anyone know what causes it, and what needs to be replaced to fix it?

 

[ollie240585]

I believe it is something to do with the ECU getting confused. This usually happens when the car is moved a very short distance (IE off the drive and then left). Removing the fuel pump and emptying the fuel is the nly thing you can really do. I've had it happen to me before on the old engine and ECU, but got those replaced and never had this problem since!

 

[BristolBoy]

Thanks, that's interesting - cos a move of a very short distance was exactly what I did before leaving the car for 5 days.

When you say "removing the fuel pump and emptying the fuel" do mean literally taking off the fuel pump - or do what I did and isolate it by removing the fuse?

And if a new ECU is the only permanent 'fix', how much are we talking about for the part?

 

[ollie240585]

Sorry did mean removing the fuse!!!

All I can suggest is if you move it a short distance, keep it running for a few minutes.

I don't know if the ECU is the fix. It may have been the engine, throttle body, who knows??

 

[BristolBoy]

Thanks Ollie - I'll try not to confuse the ECU again !!

 

[Ed]

When you first start the car the ECU chucks in alot of fuel for cold start + cold start fuel enrichment. It seems if its quite cold the ecu injects too much, and if its not run for a few moments when this happens the following time that will be enough to flood the car. Just how nissan programmed the ecu.

 

[bens851]

its happened to me pleanty of times!
i did it 2 days ago, i started the car and then stalled it!
so i had to push my damn car to the side of the road and get angry and sort it out, its bee missfiring quite a bit since, which is brilliant!
anyone got any soloutions to the missfires?
it did it a few times today too.
cheers

 

[m-hayes]

If it's any consolation apparently most fuel injected cars will flodd if driven a short disatnce. I had never heard of it until I had a Rover 416 do it. I couldn't start it and called the RAC. He told me what it was and that whilst it isn't exactly common it does happen quite regularly.