Every Morning, Car Stalls On Acceleration When Idle. Help?

[AlexB]

Yes, this is the upstream sensor. The other one is just for checking the cat.

Use the dielectric grease when installing the coils. If they have silicone rubber boots, then use the fluorine grease, otherwise a cheap high-voltage silicone grease will do. See my post in Parts section.

Was one plug of a different colour?

Hi Alex,

There is 1 o2 sensor which alternates fast. Is this the one I should be looking at?

I can try taking a laptop after work and checking the o2 sensor after the journey today.

Also i have ordered 4 Valeo Ignition Coils to see if this fixes the issue.

In my mind i believe it to be the VVT again. But im no expert.

[simba7]

Hi Alex,

Yes they have a green top which means i think means they were manufactured by Valeo.

See below link
https://www.ebay.co.uk/itm/FULL-SET-PENC ... 232e02ff76

What grease will be appropriate for them?

Thanks

[AlexB]

No idea; in rs250 they are different.

Regarding the grease please see my post in Parts section. Renault use the fluorine grease in order to avoid compatibility issues with silicone rubber of the coil boot. I guess some coils use silicone rubber, some a different material.

If you have the coils, just check whether the rubber feels like silicone or not. I bought a small tube of Krytox 205 from eBay just to be on a safe side.

Note, not all silicone and PFPE greases are suitable, only those with high electrical strength.

[simba7]

Hi Alex,

I have read your post about the grease and have even asked renault for it and they want 38+Vat which i think is quite pricey.

Can i use Krytox 205 for both silicone and rubber to be on the safe side?

I may just do that if it is very important to grease them.

Thanks

[simba7]

I have some Comma multipurpose grease.

Can i use this?

It is A lithium-based grease
https://www.commaoil.com/passenger-vehic ... 0/GR2500G/

It says it is Suitable for chassis, wheel bearings, hubs, universal joints and electric motor bearings.
Good temperature tolerance - stable in hot conditions but still flows when cold.

Thanks

[AlexB]

No, it's not a good dielectric. We are talking about more than 30kV voltage, which breaks 1cm of air! This Comma lithium grease is based on mineral oil and is not a high temperature lubricant.

Yes, Krytox 205 is suitable for any rubber, including silicone rubber. It's a very high tech product. I'm suspecting that most fluorine greases and oil on the market are rebranded Krytox.

They are all different sorts of rubber, by the way. Rubber can be natural, silicone (high temperature, high voltage, soft), nitrile (fuel and chemically tolerant), etc. Natural rubber swells in petroleum substances, silicone rubber swells on contact with silicone oil, etc. There are books written about these.

I have some Comma multipurpose grease.

Can i use this?

It is A lithium-based grease
https://www.commaoil.com/passenger-vehic ... 0/GR2500G/

It says it is Suitable for chassis, wheel bearings, hubs, universal joints and electric motor bearings.
Good temperature tolerance - stable in hot conditions but still flows when cold.

Thanks

[simba7]

Thanks for the explanation Alex. I will use the Krytox

I also recorded the o2 sensor reading after the journey below.

https://s7.postimg.org/63pwka6a3/o2afterjourney.jpg

[simba7]

Hi Alex,

Also i would like to say, every morning my car idle drops on its own and nearly stalls before coming back up again.

I have plugged in a professional tool compared to the elm and it has reported DF092 which is upstream oxygen sensor. Could this be causing it?

Thanks

[AlexB]

Yep, the first O2 sensor might be culprit. The trim is pretty far from zero, so on startup, when the system is in the open loop mode, the engine chocks. Then it goes into closed loop control mode and becomes more stable.

[mickeybo]

The throttle position sensor or it's wiring would need to be checked out on this vehicle. Regards Mickeybo

[simba7]

Car threw up a flashing EML again while driving, saying engine misfire cylinder 3 P0303. Even though i changed the Coils so it cant be them. Sparks ive changed recently.

The ECU captured Freeze Frame Data which ive taken a photo of.

Page 1
https://s17.postimg.org/luj3ycg73/IMG_20140225_00006.jpg

Page 2
https://s28.postimg.org/qkxm3jk8t/IMG_20140225_00005.jpg

What do you think of that?

[AlexB]

So, what is unclear about it? Positive trim due to lean O2 readings caused by oxygen not burning in one cylinder... The unburnt mixture, obviously, reaches the cat, burns there and causes rich readings in the downstream sensor.

This is usually caused by coils, and the coils are frequently damaged in servicing by not applying the dielectric grease. Most of them fail after servicing. You installed them DIY and then removed and installed them again...

[simba7]

Hi Alex,

The old ignition coils bought up the EML light hence why i replaced all 4 of them but the light still flashes.

Grease was applied so we can rule out the coils.

Going to order some spark plugs today and see if that resolves the issue.

Is Cylinder 3 the third from the left or right?

Thanks

[AlexB]

Hi Simba,

Correct installation does not rule them out. The problem can be with a wire or connector or something else causing misfire. The grease can be of wrong type... I don't know exactly what is at fault, but the trim values combined with the earlier o2 readings and the misfire code form a recognisable pattern.

The cylinders are counted from the gearbox side.

It can be an injector as well, but then the downstream o2 readings do not make sense. No sense mean either a wrong assumption or a faulty sensor...