Stalling problem - any suggestions please?

[RS200CUP]

Hi
My first post on this forum.
I am the sole owner of a 2012 RS 200 Cup (Mk3). Car has been excellent car to date but has now started to experience the following stalling issue.
Full description of symptoms is below.

First symptoms and fix:

• car randomly stalled when coasting to a stop
• Restarted on second attempt
• Drove good for another week but then completely failed to start
• RAA returned a fault code (Cat converter in poor condition)
• Towed to Renault dealer
• Cat and exhaust blocked. Removed cat and exhaust, crap blown out, O2 sensors cleaned
• Car good for a few weeks driving and a couple of longer drives
• Burning smell under hard acceleration

Second symptoms:

• Car started and then immediately stalled
• I had just refilled to a full tank with 98
• Restarted after 10 minute wait
• Towed to independent Euro specialist
• One error message only (injector 1, 2, 3, 4) and found no injector pulse
• Mechanic demonstrated that car will fire if fuel is manually fed into manifold by hand (ie proven that car is failing to fire as no fuel)
• They suspected ECU and sent me back to Renault
• Car failed once on way home from mechanic but restarted

Renault Visit 2

• Drove to Renault dealer
• Car failed twice on the way and restarted first go each time
• Dash error message came up saying "check injectors”
• Returned same injector error (1, 2 ,3 4) as above at the dealer
• Loose wire diagnosed and “fixed"
• Error cleared, system reset
• Sent home but immediately I could feel sluggish performance under acceleration
• Car then stalled twice on way home
• Each time restarted after about 10 minute wait

Renault Visit 3

• Towed back to dealer
• No error messages being returned at all
• Changed TDC (crank sensor) at my direction as have read it’s a known fault that can cause stalling when coming to a stop and seemed best place to start
• On drive home, car performance seemed back to normal and sat nicely at 1,000 rpm when stopping
• Then after about 5 kms, started to drop to around 800 or slightly lower
• Performance on acceleration then became jerky
• Then stalled when stopping at lights and would not restart
• RAA put fuel into manifold, immediately fired, revved it back to life and got home

So basically, car is intermittently stalling when I come to a stop every time I drive it and fuel is being cut of from the engine.

Reaching out as dealer seems mystified and wondered if the above rings any bells with another owner.

On forums TDC sensor comes out as main likely cause but that’s now ben ruled out. Other suggestions on some forums are:
- fuel pump
- O2 sensor
- MAF sensor

But maybe first mechanic got it right (ECU)?

Any help much appreciated.

 

[DS197]

Fuel pumps are known to fail on these. It’s not a hard fix if you’re willing to take a shortcut and cut an access hole in the car. Unlikely to just be the injectors at fault but what condition are they in?

 

[RS200CUP]

Thanks DS197. Injectors have been checked and ok'd.

In parallel to posting this, I have also run the above list past another independent mechanic and they also say ECU (and yet I don't see any references to ECU issues on these forums).

 

[Frank Perry]

My fuel pump failed after hitting a "medium sized" pothole a few years ago. I have read on multiple fuel pump failures and most say it's intermittent and a good whack with the palm of your hand on the fuel tank under the car can sometimes bring the pump back to life.

For what it's worth and the time (and potential costs) that you have already invested, you are aware the fuel is being cut off... If you're handy yourself, you can replace the fuel pump yourself. Otherwise, it's not a 'massive' job and to rule it out as a potential point of failure, get it done.

Some users on the forum have replaced with Walbro pump as they're well known - I haven't done this myself as I bought a second-hand pump/sender unit but some others on the forum have and seems to work fine. Not sure if THIS is the right one but with a little research I'm sure you'll find the correct Walbro part number.

Perhaps if it fails again, reach underneath your car and give the tank a good few whacks with the palm of your hand and see if it starts again. That would point towards the fuel pump!

MAF and O2 sensors wouldn't stop the car from firing up, only make the car run lumpy and potentially stall when coming to a stop but from experience, it wouldn't stop it from failing to start again.

Hope this helps and keep us updated!

 

[RS200CUP]

Thanks Frank. Thesis very helpful advice, so much appreciated. I have zero car knowledge / mechanical ability but it seems likely that it is down to fuel pump or ECU (injector deriver failing when hot). With your pump failure, were the symptoms similar to above?

Going back to dealer next week. And yes I will advise once I know the issue is sorted.