Megane 250 Hesitation

[Rojer]

Hi everyone,

I am having a problem with my 250. It only happens occasionally, but under part throttle just slowly accelerating the car can have a big hesitation. Almost like you are hitting a brick wall or just hit the brakes hard, it only happens for a second then the car returns to normal. It happened again tonight and I saw the engine light flick on then back off. Sadly my little code reader doesn't see any faults so I will get it plugged into a proper machine at the weekend. Has anyone had any experience of this before?

The car has the following relevant work done recently

* Genuine Thermostat
* Genuine plugs gapped to 0.6mm
* Genuine coils
* Genuine fuel filter

The car has been mapped at Chris at EFI and funnily enough it did it on the way to his (car was running an Engine Dynamics map) when I was coming up the slip road. It has since done it a couple times since. I always run it on V Power and I have ran some Redex through a couple of tanks. Whilst at EFI, no issues were found apart from Chris needing to adjust the stock actuator as it was a little weak.

Mod wise the car has

* Wagner Intercooler
* Pure Motorsport sports CAT
* Pure Motorsport CAT back exhaust
* EFI remap

Any help would be appreciated as I'm supposed to be going on a road trip in a couple of weeks!

 

[Krarl]

 

[Rojer]

Yer i thought that might be the reaction.

 

[AdDaMan]

Dodgy injector?

 

[Rojer]

Dodgy injector?

Could be, but the car runs fine up to the redline with no issues and 99% of the time its fine. I was thinking the FPR on the rail maybe the pump, it seems like a fuel issue to me.

 

[Scrooge]

Literally pissing into the wind without looking into the faults codes first tbh

That should hopefully tell you all you need to know at the weekend.

 

[Rojer]

Literally pissing into the wind without looking into the faults codes first tbh

That should hopefully tell you all you need to know at the weekend.

Yer I know, it was a bit of a longshot just to see if anyone else had experienced it before.

 

[Inequality Street]

s**t driver could be the issue

 

[Rojer]

s**t driver could be the issue

Must be why your Cayman is always in the shop...

 

[Ex-User (60778)]

Hi everyone,

I am having a problem with my 250. It only happens occasionally, but under part throttle just slowly accelerating the car can have a big hesitation. Almost like you are hitting a brick wall or just hit the brakes hard, it only happens for a second then the car returns to normal. It happened again tonight and I saw the engine light flick on then back off. Sadly my little code reader doesn't see any faults so I will get it plugged into a proper machine at the weekend. Has anyone had any experience of this before?

The car has the following relevant work done recently

* Genuine Thermostat
* Genuine plugs gapped to 0.6mm
* Genuine coils
* Genuine fuel filter

The car has been mapped at Chris at EFI and funnily enough it did it on the way to his (car was running an Engine Dynamics map) when I was coming up the slip road. It has since done it a couple times since. I always run it on V Power and I have ran some Redex through a couple of tanks. Whilst at EFI, no issues were found apart from Chris needing to adjust the stock actuator as it was a little weak.

Mod wise the car has

* Wagner Intercooler
* Pure Motorsport sports CAT
* Pure Motorsport CAT back exhaust
* EFI remap

Any help would be appreciated as I'm supposed to be going on a road trip in a couple of weeks!

Could it be the diff?

 

[Rojer]

Could it be the diff?

Well someone had to say it.

 

[Mbeau]

Has it got RS Monitor? Put the temperature on screen and have a look what its reading. I know you have a new thermostat, but that was exactly what mine did prior to fitting a new one.

I am assuming your code reader does not show live data?

 

[Matt e]

Coolant Temp Sensor?

 

[-Jamie-]

Could be, but the car runs fine up to the redline with no issues and 99% of the time its fine. I was thinking the FPR on the rail maybe the pump, it seems like a fuel issue to me.

Doubt it's either of them, Never heard of any failures on a MK3

Injectors is a good shout and give the CTS a change

 

[Rojer]

Has it got RS Monitor? Put the temperature on screen and have a look what its reading. I know you have a new thermostat, but that was exactly what mine did prior to fitting a new one.

I am assuming your code reader does not show live data?

It has RS Monitor yes, but it doesn't show coolant temp only oil temp iirc. My code reader is a very very basic cheap s**t one so no live data sadly. It will be plugged in with Clip tomorrow so going to check codes and hopefully that will give us something to go on.

Even though I have a new thermostat the gauge will sit on the third mark on the picture below.

Doubt it's either of them, Never heard of any failures on a MK3

Injectors is a good shout and give the CTS a change

That's what the garage said when I spoke to them. If it was ignition related It would give a misfire rather than a hesitation. We plan to put an inline gauge on the fuel line just to check the fuel pressure is OK. I think the same would happen if it was an injector, Its highly unlikely all 4 would go at once and that would cause a misfire as well.

Its either fuel or sensor related as an educated guess, but hopefully Clip will reveal all. As Nick mentioned on rsmegane, it could even be a break in the wiring.

 

[Hixle]

Mine also sits on the third mark mate, that’s normal 👍🏻

Definitely sounds sensor related, no warning messages like ‘check ignition system’ etc?

 

[Rojer]

I didn't see anything, I only caught the orange of what seemed like two lights on the dash for a split second then it went off. I will have to check the dash lights to try and remember which two it was.

 

[Rojer]

Just to add to this, when the car had a hesitation first time we plugged it in and got the following, but we were unsure if they were just stored old ones. So if the same codes return we know that they are active.

DTC061A61 - COMP
DTC042009 - Catalytic Converter Function Fault
DTC013011 - Upstream Oxygen Sensor Circuit

I did mention to the garage this morning about the O2 sensor, but he said that Chris monitors long term fuel trims so even if the sensor fails and the car wants more fuel it should reference the table and say no.

Also the CAT fault was showing as active in Clip so I asked Chris about it just to make sure he mapped the secondary sensor out and he said he did so it is a bit strange to be honest. Hopefully tomorrow will bring answers and it could just be the O2 sensor which would be a massive relief!

 

[-Jamie-]

Should be an easy fix once you get the actual codes of the issue, hopefully doesn't turn out to be a burst Ringland or the likes that a few have suffered from

 

[Mbeau]

It has RS Monitor yes, but it doesn't show coolant temp only oil temp iirc. My code reader is a very very basic cheap s**t one so no live data sadly. It will be plugged in with Clip tomorrow so going to check codes and hopefully that will give us something to go on.

Even though I have a new thermostat the gauge will sit on the third mark on the picture below.

View attachment 1534388

That's what the garage said when I spoke to them. If it was ignition related It would give a misfire rather than a hesitation. We plan to put an inline gauge on the fuel line just to check the fuel pressure is OK. I think the same would happen if it was an injector, Its highly unlikely all 4 would go at once and that would cause a misfire as well.

Its either fuel or sensor related as an educated guess, but hopefully Clip will reveal all. As Nick mentioned on rsmegane, it could even be a break in the wiring.

Third including the one its sat on? Can you get a picture of it when warm although does need plugging in really for accurate reading.

 

[Rojer]

Third including the one its sat on? Can you get a picture of it when warm although does need plugging in really for accurate reading.

If you imagine the gauge reading bang in the middle it's the mark to the left of it.

 

[Mbeau]

If you imagine the gauge reading bang in the middle it's the mark to the left of it.

Needs confirmation, but in my experience that is reading too low. Does rev limiter seem to cut in early?

 

[Rojer]

Needs confirmation, but in my experience that is reading too low. Does rev limiter seem to cut in early?

Nah goes to the redline fine, the old one was definitely shot as the pin had punctured the thermostat. I could change the CTS to be safe, but I think alot of people have the gauge in the same place. Previously I noticed the gauge would go back down where as now it stays solid and car warms up quite quickly.

 

[JamesBryan]

Nah goes to the redline fine, the old one was definitely shot as the pin had punctured the thermostat. I could change the CTS to be safe, but I think alot of people have the gauge in the same place. Previously I noticed the gauge would go back down where as now it stays solid and car warms up quite quickly.

Yeah 3rd line/mark is correct as that's half way between the 1st and the 5th.

Most think it's half way between either end points.

 

[Rojer]

Not great news sadly, driving to the garage it did it again. Plugged it in and the only code was COMP, same as the one I posted before. When you click into that with clip it just says has the owner reported an issue if yes refer to technical. If no replace injection computer.

So we think it's going to be a break in the loom somewhere. Ran out of time to check fully today so left it at the garage. Hopefully it's an easy find and fix!

Kev is going to reach out to Renault and hopefully they can point us in the right direction.

 

[Rojer]

Just to update this, the loom has been stripped quite far back and no issues have been found in the common areas. Generally with Clip if there was a wiring issue it would say which circuit. Andy at Engine Dynamics had a car with the exact same code and they tried everything but they ended up replacing the ECU and that solved it. I have another ECU coming tomorrow so fingers crossed that does the trick otherwise I'll have to order a new loom.

 

[-Jamie-]

Cursed Megane strikes again [emoji28]

 

[Rojer]

Indeed it does, but another ECU costs £70 so it's the cheapest option to start with.

 

[Krarl]

£70 for an ECU is absolutely nothing!! If that fixes the issue then it'll cost less than an hours diagnostic at a reputable garage

Fingers crossed its just that

 

[Rojer]

New ECU done the trick. Been driving it for a few hours and no issues so seems to be sorted. He mentioned the battery is a bit weak so I'll replace that.

 

[AdDaMan]

Mad. f**king ECU just decides to give up 😂

 

[Rojer]

Mad. f**king ECU just decides to give up 😂

Does seem really random, but after speaking to some people its starting to become more common. I'm just glad it's fixed. I'll do some more miles over the weekend to make sure.

 

[Rojer]

If anyone knows the right specs for the battery that would be great

 

[VXR killer]

If anyone knows the right specs for the battery that would be great

I got mine from halfords, hcb013 or hsb013 and it was spot on size and shape wise with standard. I went with the more expensive battery thou.

 

[VXR killer]

Looks like 027 is the same

 

[Rojer]

Surprisingly weak I thought

 

[VXR killer]

Been running yuasa one from halfords for years, starts n runs fine. Even when its been standing for periods.

 

[npt]

Could be related to the tps or throttle body, you'd need to plug it in and start checking the parameters of all sensors etc are reading as they should both hot and cold and when on heavy load, best to just drive it around collecting live data via obm port which might help, could be anything from plug gap or a bad lead..good luck

 

[FatRS]

Is none of this covered by warranty by K-Tec?