What am i doing wrong?

[MeteorGray]

Originally Posted by iikhod

This is exactly what i meant, thank you.
I have heard somewhere that driving with ethanol would clean off them build-ups even better?

I hope that's true, because a 10% ethanol mix is all I can conveniently get around here. And even though straight gasoline is available in a couple of places, its extra expense doesn't seem to justify its extra MPG potential nor the efforts it takes to find and go get it.

Thanks go to our influenced politicians for this contrived state of affairs.

[cRiPpLe_rOoStEr]

Originally Posted by MeteorGray

I can't prove the Italians know what they are doing, but I "think" the technique helps keep the spark plugs and valves a little cleaner than they otherwise would be. The use of good quality gasoline which contain the proper cleaning additives also helps, I "think."

Not sure about the effectiveness of the "Italian tune-up", but in light aircraft still fitted with piston engines it's not unusual to lean the mixture for a while in order to increase the temperature in order to eliminate lead fouling around the spark plugs' electrodes. But anyway, at least in a port-injection engine, I wouldn't expect too much carbon buildup around the valve seats, even though in newer cars with direct injection the fine particulate matter emissions have increased to Diesel-like levels.

[Michaelflat1]

I have a similar problem, my car runs like dogsh*t sometimes after hypermiling, needs a good thrash.

Normal driving (keeping it loaded at low rpm) it clogs up something (i'm not sure what.. EGR?) and thrashing the car helps.

Normal thrashing can help sure, but also in a low gear (2nd gear 40-50mph on my Jazz) high RPMs i find transitioning from lowest throttle state (that's not DFCO) to max throttle state, over and over to help. I think this makes the ECU move the EGR a lot and can solve the sticky valve somewhat.

My throttle pedal is definitely adapted to the driver, it becomes more relaxed when i drive it (changing mapping mid drive sometimes which is annoying, my rev matched downshifts can be messed up by this a little). But when the car is running bad, it feels like it's always in both too high and too low a gear. (hard to explain really).

[Michaelflat1]

I cleaned my EGR and it was very carboned up, car runs nice, all the time.
Recommend resetting your ECU afterwards though (disconnect battery for a few mins or so)
And it'll take a little bit of time for all the values to be learnt back, but it's amazing how much better my car is now.

Throttle pedal is instant! No more running on exhaust gases when it shouldn't be, also mpg has improved too..!

EGRs and throttle bodies seem to require cleaning i think, i need to do my throttle body next, but the EGR has helped a lot.

[cRiPpLe_rOoStEr]

Did you also take a look at the crankcase venting (PCV)?