A610's cut out... 'tis a 3 litre thing

Well, I've had my 610 back for a week or so since the new steering rack was fitted. They might only be £175 on exchange from Renault, but is absolute frucking britch to fit.

...and it cut out on my on the way home. EXACTLY the same symptoms as my Venturi did, which are also known for doing it.

The behaviour is absolutely consistent with a solid state device reaching its thermal overload setting. If you reset the power supply, it wakes up, but cuts out very quickly with anything more than a tiny amount of throttle (ie it's set to cut out at a higher temperature than it cuts back in). Let it coast for 15 seconds or so and it wakes up of its own accord and works for proportionately longer before conking out again. It's definitely related to throttle position.

The only difference between the Venturi and the 610 is that the engine light works on the 610, and with the ECU cover off, I can also hear the injector power supply relay cutting. The spark defintely continues to work, tested in the Venturi with the engine bay access cover removed (noisy!).

Over long and annoying periods of time, I eliminated all sorts of other possibles on the Venturi, and am convinced it's related to the heat of the ECU box, which accoring to Mr Dell is soemthig the French have suspected for a while too.

They never cut out from cold, only after extended periods of driving and/or heat soak after sitting when hot.

I'd love to get some insight into why the 3 litre ECU would have this problem while the 2.5 doesn't, but for anyone who experiences these issues, my advice is start by putting an air-gap between the ECU and bulkhead (that goes for Venturi people too) and removing the carpet cover. It was certainly very warm in there the other day when it cut out on me.

I've had it with the GTA on the Renix and I think the Adapt suffers as well .Being plonked right behind the turbo .........after a good days thrashing it will want to stall if I let it .Once off it will take up to 20 mins to start again but once it does it's fine for the rest of the day .It could be fuel evaporation though it does it more on the Adapt than it did on the Renix .
I've spaced it off a bit more .

It's not a stalling problem, and re-starts immediately if you reset the ignition (this can be done while moving simply by flicking the key back and then forward. It's a sudden, violent power cut, usually first when just coming on boost. The Venturi did it to me more than once whilst in the middle of overtaking - very scary, embarrassing, and utterly infuriating.

After it starts, you have to drive with light throttle or it'll immediately do it again.

Martin, "GeofA610" had lots of cutting out problems with his A610, could be worth sending him a PM as I think he did some other things as well as moving the ECO off the bulkhead.

thanks Simon, will do. I know I had a chat with someone about their 610 cutting out but I can't remember who it was! Steve's does it very occasionally too, and we know of at least 2 Venturi 300's that also do it or have done it.

ah.... no such user???

[BIG_MVS]

Try A610GA

I was speaking to George Lackford(double A610 owner)when I had problems with my previous GTA (turned out to be the front fuel pump ). He fitted a fan to the ecu I beleive which solved all his cutting out issues.

My old 610 had cut out issues when i got it(although different from the above mentioned) it would cut out randomly when the engine was up to temperature but never when the engine was cold.
Geoff did help me fix my car, turned out it was the wiring to the lamda sensor, traced the wire from the lamda connector back to the main loom, chopped out burnt wires and replaced with new wire, never happened again after this fix, through time the heat transfers from the exhaust down the wiring damaging it and causing bad signals to the ECU

My GTA Turbo would cut out similar to what you are experiencing. After lots of replacement of parts, it was found to be the front fuel pump seizing, but this would only happen after about 40 minutes of driving. After a 10- 15 minute wait I would then be able to drive for another 15 mins.

When the pump would seize it would then drag more current and so caused a voltage drop on the circuit which also has the rear pump on it being fed from the same relay. I had heard the rear pump howl when this would happen and I tested to find low voltage to the pump.

I replaced the rear pump and the relay, but it took me some months of experimenting, and cleaning earths etc to work out it was the front pump causing the problem.

I also thought the ECU was getting too hot and having problems. I disproved this by taking off the cover and putting a wet towel over it when driving with no change.

[stephendell]

With the 610 cut out problem, mine will always re-start immediately following the cut-out, no need to wait for a cool down or similar. And it only usually does it once on a trip. Once it's cut out once it normally doesn't do it again.

It normally happens when I'm sitting in a queue or slow moving traffic. I can do a 500 mile round trip with no problem, and be sitting in a traffic jam on the motorway and it will stop for no apparent reason.

It's so infrequent (at the moment!) and immediately re-starts so I don't worry about it too much.

Would be nice to eliminate it completely but it's so infrequent I'd have to drive it every day for months without incident to prove the problem had gone!

The people who have had most problems and susequently most improvement seem to be those who've fitted a fan or carried out other airflow improvements to the ECU which seems to indicate a temperature related component overload or re-set.

Hi,
these are my 5 cents:

The 3L has the same throttle body sensor and throttle body as my R25 V6T kat / 205 HP.
The insulation seems to suffer from the heat and dissolve. This is when a short between all three wires can occur. I changed the sensor when I got the car and never experienced the symptons you describe.
Neither am I sure if a short there can make the ECU cut off the fuel supply.

Still, I reckon it is worth checking

daniel

[mettersl]

Fortunately my 610 hasn't done this yet- and as it can't read I hope it won't get any ideas...
One of the CAR guys I spoke to said his had been cured by fitting a new battery- recommended by a French specialist. I don't have any other corroborating evidence, but it would seem worth a go (maybe Stephen that would explain the traffic thing- when you are moving the alternator holds up the voltages, in traffic it falls to the battery levels?).
There seem to be so many stories about this one that it must be a combination of factors.
Heat damaged wiring, over hot ECUs both seem credible, but it could be anything (and everything described) in the wiring.
Why worse on the 3 litres? Isn't the ECU a Siemens item on an A610 and on the GTA its RENIX? On my code reader the settings are different for Siemens ECU to the earlier units, that could explain some of why its worse on 610/Venturi.
As an upside the Siemens ECU is also said to be remappable if you have the software tools.
Somewhere I have a sheet from Geoff of everything he did to cure his, but I can't find it just now. If I do I'll let you all know.
Cheers
Lee

I would imagine its worse on the 3 litres as they all have lambda's, any lemans have the same problem?

This is how Geoff fixed his car, it worked for me also.

armed with a Fluke 47 meter I measured every aspect of the engine wiring. Having found all sorts of high resistances, I took a Stanley knife to the loom and found the following:
Problems were:
1 High resistance in connector plug to Oxygen sensor. Replaced with individual terminals.
2 Breakdown in blue data lead from Oxygen sensor to multi connector.
3 Breakdown / corrosion in positive lead where it crimps from single connection in multi connector to 6 smaller red leads in the engine harness. Some leads were also high resistance having been overheated. Repair included soldering the connections. Replaced lead to Oxygen sensor and a couple of others.
4 Breakdown / corrosion in negative lead where it crimps from single connection in multi connector to 6 smaller brown leads in the engine harness. Some leads were also high resistance having been overheated. Repair included soldering the connections. Replaced lead to Oxygen sensor and a couple of others.
5 High resistance in leads to the 2 air temperature sensors. Leads were mostly ok but terminals were corroded and needed replacing. Connection in engine loom was also corroded and of crimp type. Cut, cleaned and soldered.
I also checked all the power feeds and earths on the car, breaking, cleaning and re-making them all. The car now worked fine except for a high end missfire.

Hi Guys, thanks for the numerous ideas. I think we're discussing anumber of different causes, but the front fuel pump failure is an intersting one - especially that it only does it when cold.

However, there's one thing that's worth noting - the engine management light comes on when it cuts out and I hear the fuel pump/injector relay trip. These are dumb devices and won't switch off if too much current is drawn - you'd blow a fuse instead (in theory). If it were a fuel pump issue, the ECU wouldn't know there was a problem, it'd simply "see" the engine get slower and meter the fuel (ie fire the injectors) accordingly - whether or not that fuel is delivered. Unless it uses the lambda signal to the extent that it's suddenly see everythig runnig massively lean. Hmmm.

Would the front fuel pump failure cause a complete cut, or would it just prevent the engine from revving properly under load?

I went through the throttle pot wiring and lambda sensor wiring on the Venturi with no joy (and the fuel pressures were spot on - plumbed in a gauge into the cockpit to keep an eye on it). If the throttle pot were malfuntioning, the second stage boost doesn't work on the 3 litres (610 and Venturi)

The Venturi ECU is a Siemens unit but says "Venturi" on it. The only differences I could find were that the engine runs a higher fuel pressure.

It's pure speculation, but if the injector driver in the 3 litre ECU is the same as all the other PRV units, it's conceivable that the 337's draw a higher current and this then reaches the threshold of the device - which after a few years starts to build up a little more internal reisstance of its own.