VersaTune User Forum

Hi it’s time again to change my spark plugs so I’m looking for spark plug and gap recommendations for a gen 2. I’m currently running the high load tune and the only current mods are hpfp internals, corksport stage 2 short ram intake and gfb recirc valve.

Also I don’t have much knowledge but the car is running rich atm, I can smell fuel in the cabin after a pull and sometimes when idling , I also get a puff of black smoke after hard acceleration, I have recently had the intake valves cleaned and fitted cs injector seals. I have checked the fuel rail pressure I think is fine (roughly 500 psi at idle, 1800 psi at full throttle) if you have any advice or suggestions I’d appreciate it thanks.

If the fuel rail pressure is 500psi at idle then you probably have a small problem somewhere, assuming we're talking about warm idle, no AC.
If you suspect the car is running too rich then please take a log and post it somewhere here. Please use this logging preset to take the logs: https://www.dropbox.com/s/i0ndre5umzanz ... vtpre?dl=0
Take 2-3 logs 1 minute each driving normally and one with the car idling for at least 20 seconds, plus one 3rd gear WOT log, let's see what's up.

As for the spark plugs, in your case stock heat range should work just fine. I recommend NGK spark plugs: 3787/ILTR6A-8G, 6509/LTR6IX-11 or if you can find them LTR6BHX.
You can also go a step colder: 6510/LTR7IX-11 or better the 95605/LTR7BHX.

As an alternative and only if you can't find NGKs in a reasonable amount of time you can go with the Denso ITV20 for OEM heat range or Denso ITV22 - one step colder.

Some of these spark plugs need to be re-gapped to 0.7mm (the 6510 are by default gapped to 1.1mm).

Thanks for the reply, I’ll get some plugs plugs ordered, I found NGK 95605/LTRBHX they sell them gapped to 0.711mm for a me 3 focus st would this be okay?
I’ll get some logs tonight and check back in.

0.711 is really 0.7 realistically speaking Probably they gave the gap in inches and when converting you ended up with a few more decimals

hi theses are the logs. if you could take a look id appreciate. thanks.

Ok, one at a time:
1. your car seems to be working decently.
2. the gas smell in the cabin may be due to an exhaust leak. Possibly you have an exhaust leak before the O2 sensor because I can see it's reading weird at times (fuel trims are possitive while the AFRs are slightly richer than commanded);
3. Under load everything looks ok;
4. do you have a pops&crackless maps? This is how it looks like...

Thanks for looking, I am not running the crackle and pop map just the normal high load, I have changed the lowest idle rpms to 800 to reduce flywheel chatter, I don’t know if this would affect the reading?
Good to know it’s nothing serious though, I’ll try nvestigate an exhaust leak that would make sense.