200 missfire no codes

[redrs200-12]

Hi, I've got a 200 that one day rapidly developed a missfire while driving one morning, I've changed the plugs, coils , injectors and both lambda sensors and still no joy, I did have missfire codes for all for cylinders but after changing the no2 lambda I've only seen one code which said cam position sensor circuit fault but since clearing hasn't come back, it's now running slightly better over 5krpm but still sounds like a subaru, stinks of fuel and running rough as a badgers backside, when unplugging coil 1&4 it stalls out fast but when 2&3 are unplugged it makes little difference, I've compression tested it and all 4 cylinders are at 180psi give or take 1 or 2 psi, its really driving me mad and thought I'd post here before spending more money on the thing

 

[R20BTG]

Try a different throttle body

 

[Frank Perry]

You 100% sure the plugs were genuine and the correct ones for the F4R engine? Coils and injectors, were they brand new and genuine renault? Same goes for Lambda sensors....

Cam sensor might be worth looking at. I think most people pull theirs out and clean them up with some success...

Have you got any exhaust or intake mods but not had it mapped? Rough running can sometimes be caused by changing the exhaust and is usually sorted with a map.

As R20BTG mentioned, throttle body isn't too much hassle to change either. Might also want to consider the map sensor, get it held in with some cable ties so it's not loose.

Good luck!

 

[spicer92]

Have you checked for cracked exhaust flexi's, exhaust flange where it bolts to the engine, or any other parts of the exhaust leaking?
As frank said, exhaust changes (or leaks) can cause noticeable problems on these. Look out for black soot to easily spot a leak on the exhaust.

Changing the cam sensor also improved mine when having a slight misfire issue.

 

[redrs200-12]

You 100% sure the plugs were genuine and the correct ones for the F4R engine? Coils and injectors, were they brand new and genuine renault? Same goes for Lambda sensors....

Cam sensor might be worth looking at. I think most people pull theirs out and clean them up with some success...

Have you got any exhaust or intake mods but not had it mapped? Rough running can sometimes be caused by changing the exhaust and is usually sorted with a map.

As R20BTG mentioned, throttle body isn't too much hassle to change either. Might also want to consider the map sensor, get it held in with some cable ties so it's not loose.

Good luck!

All the parts I've used on the car so far have been genuine, I'm a bit anal over that sort of thing, I'm starting to think it's throttle body now as I've checked it anywhere a possible vac leak could have popped up, it's got a completely factory intake and has a toyo 4-2-1 and a resonated scorpion exhaust still running the secondary cat, I was driving it hassle free for nearly 9 months like that, it does also make a strange hum/wine on cold on and off for the last 3 months of ot being on the road but hasn't affected it and still does it now, I'll try a throttle body and update once it's changed, thank you

 

[redrs200-12]

Have you checked for cracked exhaust flexi's, exhaust flange where it bolts to the engine, or any other parts of the exhaust leaking?
As frank said, exhaust changes (or leaks) can cause noticeable problems on these. Look out for black soot to easily spot a leak on the exhaust.

Changing the cam sensor also improved mine when having a slight misfire issue.

I've been through the exhaust front to back, found one leak on the clamp after that cat and since changing it there's no leaks or difference

 

[Frank Perry]

Got anybody close by who has known working coils and plugs? Swap the over... you said in your first post that unplugging 1&4 stalls quicker than unplugging 2&3... perhaps you've got a duff coil or faulty plug?

Have you had it scanned by a proper scanner and had somebody who knows what they're looking at view the live data? Something like rstuner or clip etc...

Other than that, I'm not quite sure what else to suggest. Perhaps vvt solenoid or cam/knock sensor... or belts may have slipped/could be out of timing. When were the belts last done?

 

[redrs200-12]

Got anybody close by who has known working coils and plugs? Swap the over... you said in your first post that unplugging 1&4 stalls quicker than unplugging 2&3... perhaps you've got a duff coil or faulty plug?

Have you had it scanned by a proper scanner and had somebody who knows what they're looking at view the live data? Something like rstuner or clip etc...

Other than that, I'm not quite sure what else to suggest. Perhaps vvt solenoid or cam/knock sensor... or belts may have slipped/could be out of timing. When were the belts last done?

It's got new ngk plugs in it and I've moved around the coils and the missfire doesn't seem to move, I'm gonna try to get a video of it today

 

[R20BTG]

With it being a wasted spark setup (Cylinders 1&4 fire together and 2&3 fire together) it can be easy to think you’re swapped a coil or plug but you actually haven’t and the fault remains on the same pair. Believe me, I’ve done it!

I would remove all coils and plugs from the head. Connect them back to the coils and ground them one by one on the block and get someone to crank the car over each time. Compare the strength of the spark that you can see. That will tell you exactly which cylinder isn’t firing.

Once you know which cylinder it is, change plug and coil one at a time to see if the fault moves. If it moves, it’s either the plug or coil. If it stays, it can only be a fault on the loom. A broken or damaged wire on the coil loom is not unheard of, I’ve seen pictures of it happen. It’s also a suggestion on the Renault fault finding process for a misfire.

I have two spare spark plug looms if you need one.

 

[R20BTG]

Have you tried the throttle body yet?

 

[Tarticmonkey]

What code reader are you using to see no codes? I was using a basic one due to mine having issues recently and wasn't getting a code.

I had someone I know plug in with a better tool and was able to find what it was. Ironically I've got throttle body issues.... but the car isn't missfiring like you have described - just being in limp mode.

Worth looking at before just firing parts at the car hoping something will work.