A610 cutting out - solved

I thought I'd write up my experience of this fault in the hope it may be useful to other 610 owners. Firstly, I do appreciate there may be other issues with other cars and this may not be the holy grail, but it's hopefully adding something.

I've been using my car a lot recently including long trips to the Festival of speed as well as crawling around London traffic during the heatwave - basically the exact conditions that would have definitely triggered a cut-out previously. I'm therefore near certain I'm onto something.

To begin with here's a list of the stuff I've done/replaced which DID NOT resolve the issue, so if you've tried some of this to no avail then read on..

- New TDC sensor
- New fuel pump
- The fuel pump earth bypass wire trick that's been written about previously - a red herring in my experience, although it has helped others
- Insulation behind the engine management - a waste of time as it also cut out with the unit sitting on the back seat away from the engine firewall.

I believe the fault is certainly heat related. I believe it's fuel vapour locking close to the injectors.


The item that has stopped the cut-outs is the temperature activated switch that controls the blower and turbo extractor fan. And here's the issue - even if you believe your fans to work correctly, I found the switch to be temperamental with age. This needs to turn on and go off at the exact temp range as specified by Renault, otherwise the heat build up causes vapour locking at the injectors.

If you think you've replaced this item already, please read this bit:
Now, I believe the problem may have been exacerbated down the years by people fitting either the wrong switch (the engine warning light switch rather than the fan switch which I understand the workshop manual may have a misprint and has the wrong way around)

OR by buying much cheaper pattern switches online that have the same part number but on closer examination don't start and, more importantly stop the fans at the correct temperature. This means the fans don't run long enough and bring the temperatures down sufficiently.

Renault Croydon can get the part, although I had to wait some weeks for them to order it from France. The correct part number is: R6001011893

This simple item has transformed my car and as I've made each change in isolation and then given the car plenty of time to assess the changes I can say with certainty this is the difference. It goes without saying the fans need to run properly and aren't knackered.

One final observation - if your aircon does not work then you really need to run the car with at least a quarter tank of fuel. The fuel cooler that runs off the aircon pipes is important, particularly when the tank is near empty and the recirculation of fuel quickly raises it's temperature. This definitely contributes to cut-outs through vapour locked fuel.

I hope this helps someone else as this problem has troubled me for years.

Glad that you now have found the fault, and I do agree with you that it is vaper locking.
The 610 is a totally different beast to a GTA turbo, and Renault must have had this problem because of the A/C cooler for the fuel and the injector air cooling, so yes if the temp sensors are not correct this wood have an effect.
However the other parts you have fitted could have also been part of the overall problem, the reason I say this because I had solved my cutout problems but I the took the 610 to Lemans this year in mega hot weather, and slowly the problem started to come back.
We sat in traffic for an hour in Lemans in 38/40c on the tarmac and it kept going, even a modern Porche cut out in frunt of us, but once we parked up and then came back the cutting out became a big problem, in the end we cracked off the fuel line to the injection and no fuel, eventually we got fuel up and it started, this carried on all the way back home.
I then changed the fuel pump and now big pressure and start on the button, so in general it is down to there are a lot of old sensors and components that all need an update, the older cars seem to have a less vulnerable system to slow component failure and keep running.

Sounds about right

.
Excellent, well done... that will certainly help a number of members, thumbs up.

Martin

[mettersl]

Interesting debate, which could Lead to an old style forum battle!
....there are so many problems with these cars in the heat.
Wiring loom high resistance points, non working or inefficient fans, fuel pump issues.
In my first 610s case the problem was injectors that didn’t seal up when off, so the car flooded when hot and in traffic due to dribblling fuel. An Injector overhaul stopped that and the car behaved from that time on without a strap,
On the sensors the manual and parts book disagree.
My belief is the workshop manual is correct as it provides a lengthy description of what should happen and compared to this description, the parts book has the sensors the wrong way around. The gta and the 610 manuals describe very similar systems (for later gta anyway). Faulty sensors will always be an issue,
According to the workshop manuals the top sensor (hottest point) should be the lower value sensor 85 degrees?) and switch on the fans. This means they cut in earlier than if in the lower position.
The lower sensor should have the higher rating (120 degrees?) and turns on the bay overheated light. I don’t know anyone who has seen that with the sensors this way around, but swap them and the over heat light comes on before the fans do.
I’m pleased that the sensor is still available, I’d been told that it was no longer available, and it’s good to see this old topic resurface after a couple of years of absence...it means there are 610s being used.
I’ll retire to the bunker now and close the door.....

610 has it's pump a long way from the lump as well ...

As Lee M says, it's an interesting debate.

What I find particularly telling is that if you think about it, a lot of these other problems could cause vapor lock. One of the major factors on an injected car is a lack of fuel pressure in the lines (basically you're allowing the hot fuel to 'boil'), so any intermittent pressure from the fuel pump, blocked lines or filters could still give rise to the same end result (as can running too hot). Potentially a lot of the issues could be vapor locked injectors, but the actual root cause could be one of several reasons that other people have also discovered.

So are we any further down the line? I think the only thing we know for sure is that most of the A610 cases are fuelling related (as proved by the 'strap') but equally that's got an electronic root cause which we still can't source...

GTA every day....610....lardy cutouty rusty step backwards...

I do agree but the 610 is a better looking car and you can sit in it all day and do some mega mileage and get out of it not feeling to bad, once they are sorted it is a pretty good car. But a Lemans looks even better but I am bias.

Perhaps another 610 owner with the cutting out problem could try this fix and report the results here. In answer to your question Darren, I definitely think this has moved the game on and I've been grappling with this for four years.

[mettersl]

Hedley,
It’s good to know the thermostat is available and it’s key that the fans work, that’s helpful information, thanks.
My second 610 is in bits, but before that it didn’t seem to have this problem, fingers crossed when it comes back. It has plenty of other problems....
It’s a good think I enjoy fixing them...
Lee

[phildini]

GTA every day....610....lardy cutouty rusty step backwards...