Rough idle at cold start

[marty_rs]

Hi all. As per the title really.

I’m getting a little worried there might be a something up with my rs engine. So the condition it occurs at; at cold start , the initial 30 sec phase when you wake the neighbours up with your after market exhaust, this is all good and as it always has been. However the warm up phase after this when the engine settles down a little to around 900-1000 rpm ish, the idle is rough and has a splutter in it, which does sound like a misfire but no error lights or codes stored. I do recall the idle always being a little rough but not sure its been this rough 🤔 the most worrying part is whilst driving for the first 10-15 mins on light throttle every now and then you can feel a small judder/hesitation, like a misfire but not quite as harsh as a full on misfire. However once the engine is up to temp properly the idle is around 800rpm, smooth as it should be, drives perfect. I’ve only noticed this over this winter.

Mods I’ve got, mountune drop in air filter, air tec intercooler, mountune recirc valve, scorpion cat back and collins cp2( only had the map since last summer). It’s serviced meticulously, plugs changed last year if I remember right, fuel filter been changed and I’ll change that again at service in April. I have read on here about the one step colder spark plugs, as I’m using oem ones currently.  Would or should I be using the denso ones with cp2 and is that why I’m noticing this on the warm up phase. Any thoughts?

Sorry for all the text just giving as much info as I could think

Cheers

• This topic was modified 1 year, 9 months ago by marty_rs.

[faber]

Hello, colder candles are strongly recommended for any upgrade. I think they should be changed in my opinion. But I could be wrong.

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[AndyR1900]

I get this too, think the plugs may be the issue

[marty_rs]

Yeh I was reading somewhere on here about using the denso plugs when running higher bhp, but I couldn’t find if others have similar to me using on the oem plugs.

@andyr1900. Is yours standard or have you mapped yours?

[AndyR1900]

Has a stage 1 litchfield map on it with standard plugs

[AndyR1900]

I originally had a stage 2 dreamscience map on it which was fine it’s only been since I changed over to litchfield,I also feel that it’s not as smooth doing low speeds in low gears but I do have a habit of convincing myself that something is wrong when it’s not haha

[JohnD]

A properly configured map should be as smooth and progressive as the OEM

By all means change the plugs eg Denso ITV22 with gap set to o.66mm and check everything for leaks etc.  If that doesn’t improve things you need to look toward the map.    It’s easy to make more power but to do that smoothly and progressively and importantly safely, is the difference between some maps and others.

 

JohnD

 

 

[marty_rs]

True yes. I’ll check the plugs for fouling and gap, and check anything else obvious. Like Andy mentioned though it’s easy to convince yourself something isn’t right once you notice it so I don’t know.

[tonys]

Cannot comment on Litchfield however, I’ve been running Mountune FPM375, V3, and full charge pipe kit for around 4yrs with standard plugs and it runs smooth as silk!

[Lucky_]

Did you ever sort this out?

[marty_rs]

I haven’t really looked too much into it, though it hasn’t really occurred over the last few months. I’m changing the intake and breather plate for mountune items soon and going to get the injectors checked while I’m on. Make sure they’re still within tolerance

[Author]

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