Having had a few Renaults I always find it weird that common problems never have the solution well documented. And after much internet searching this seems one of them. So can anyone help please: Issue: severe stuttering/cutting out around 2.5k onwards on cold start map ONLY. Car starts fine. car idles fine. And this ONLY happens up until the car is up to temperature, ie you can see on the temp gauge the temp has come up, then dropped slightly as the thermostat opens. From this point onwards no hint of stuttering etc. No errors messages flash up. Still waiting for me obd reader to read any hidden codes though. A few times it got so bad car has gone into limp mode (when I've tried driving through the missing). Work done: New genuine plugs fitted. TDC sensor cleaned. Water temp sensor wiring checked (as far as I could. Temp gauge goes down when removed etc). Thoughts: Seems to have only done this since I removed battery and tray etc and fumbled about in that area to bleed clutch. But could be coincidence. if injectors when is it fine when warm? if it's coils why is it fine when warm? NOTE- car misses a lot worse when you pop coils/injectors off when running (so they are working, but obviously to what extent is not known). Next actions: clean injectors. clean fuel pump filter. So- anyone had this before, or could suggest what it could be? seems like it must be linked to how the engine runs when cold, ie changes to air & fuel delivery. On this - is it just a case of more fuel pumped in and the throttle valve is opened more? (There is now SAD or similar these engines is there??). anyhow - HELP!!! Any other ideas, or how you solved this problem on yours? cheers
Tbh mate without a obd reader, your just playing part roullette as to if it's the right thing etc. I'd just buy a reader and see what codes come up. I doubt very much if it's the injectors though, as when there normally on the way out you get the emmissions light flashing at you and a few coughs from the exhaust but not going into limp mode. It could be a coil just slowly degrading or it could be a sensor, map etc. As far as I know the fuel filter is built into the pump and not really a servicable item.
Mine was bad warming up and it was the thermostat , i used my smart phone and torque pro app to log coolant temp it was only getting upto around 70-80c it should run between 90-100c, the temp sensors have also been known to fail
are you sure, the water temp sensor for the gauge is also used by the ecu? several (older) renaults use separate sensors for this..
The water temp sensor has only 2 pins. I read for some Megan's (225?) that it was a 2 output sensor and the ecu controls the rad fan, which is interesting as my rad fan is on very soon after starting, then flicks on and off every 15 or so seconds. Although this conflicts with the temp gauge reading that shows a normal steady increase and then settling at the middle. couple this with the fact that it's only a 2 wire sensor and I'm a little dubious if the 225 is a twin circuit sensor. can anyone confirm? also I know its been mapped. So wonder if the rad fan ecu control has been touched?? the more I think about it, then: A- if the sensor is twin circuit, and B- The ecu does control the rad fan, and C- the rad fan is being turned on and off because the ecu thinks the engine is at X (warm temp) then maybe the temp sensor is shot?? but....... If so why am I getting a 'cold start' issue? could it be that be because the water temp is not seeing the coldness, but the air temp is and so the ecu altered the map and this is what is giving me issues? any of that sound plausible, or am I now just making things add up that actually don't?? Lol
with a shot temp sensor that makes sense, because either the sensor reports 'hot' and the ecu consequently doesn't do any cold start extra fueling, or the ecu detected the sensor is dead and defaults to 'hot' (this is probably not the case since you don't have any codes). btw, on other renaults with multiple sensors (as I mentioned above), they are not twin circuit sensors, but completely separate sensor units screwed into the head/thermostat housing, so check to see if you have multiple ones... I don't know about the fan being controlled by the ecu or not..
I do not know why someone has not mentioned that they all do this!! My last 250 Awful. First noticed after a long hot run just after Bluefinned. Took it off sent it back still did it. Varies day to day and fuel quality. My new 265 fine. Now its run in started doing it too. Usually after putting it away after a long run. Even If I start it cold let it idle. Move off then or next day Still stutters lurches kangaroos down the road like a learner. On a previous site it was well documented. That is where I found it. Cheers Andy
just let it idle for 3 minutes,problem solved, i wouldn't drive mine for at least 5 mins after cold start.
It just so happens that is what I do as it takes a few moments to start and manoeuvre out garage and drive. not a problem. I am glad we can put you mind at rest that they Do all do that sir. So used to it do not even notice it now. Cheers Andy
Is the water temp needle on your dash point straight up when its been running a while? does the needle drop when on the motorway?
Interesting comments. re needle position - yes rises to middle, and dips slightly on motorway type cruising. Did a few things to it today, but was this afternoon, so no stuttering as seems to only really do that first thing in the morning. I - cleaned throttle body. Was dirty. Seemed to make throttle changes a little smoother/refined. - found a connector hanging out of the sensor on the back of the rad under the inter cooler to tb pipe and put it back on. Based on size of wires, what the back of the sensor looked like, and the fact my dad fan is behaving like it should, I think this is the low fan speed resistor (can anyone confirm?). - diy cleaned injectors in an ultrasonic bath (yes not ideal, but wanted to gauge if a pro clean is worth it). results - wow, cleaning injectors made a huuuuuge performance difference. Car is far more aggressive in all gears. Much more as I would have expected it should be with the mods it has (full decat/exhaust, forge bov, forge inter cooler, supposed remap). So I'll be getting them pro cleaned now. As for cold performance issues - I'll be taking for an early morning spin to see. As for the "it's the norm" comments: I appreciate we generally all often adopt a 'work around' attitude to some issues. And from the lots of issues all Renaults have I can only assume Renault engine/electrics/build design/execution makes them more sensitive to issues than other marks. But I'm certain when my 56 plate 225 was new the smiley Renault salesman did not wave the new owner off the forecourt whilst it stuttered and farted it's departure. So I am now on a mission with my car to find out and sort what has made the change from then to now. i'll post my findings just in case it helps others out in the future, or indeed for input from others. cheers all again.
Right an update on this: 2 code readers seem to happily talk to the car. Both say no codes stored or pending. Wasn't expecting that!! Car is still better than it was at it's worst (does that make sense?? Lol). so - first thing in morning until cold start map finished it misses a bit, and stutters about, but not so bad now you think you're about to roll to the side of road and wait for the AA. So my plans from here are: Get a set of cleaned injectors, or professionally clean mine, and see how that is. Drop fuel pump out and clean up filter. After that I'm not too sure. Open to suggestions if anyone has any.
