[Corsa C 2000-2006] 2002 corsa c 1.4 sri 16 valve

[kipp67]

hiya guys can any one help got a prob with my corsa c 1.4 sri starts fist time drives mint for 5 mins or so fast loads of power once its warm up it starts to hold back sometimes its ok done a full service still the same no fault codes even done the pedal test trying to pull away is a nightmare it holds back and feels like its droping dwn on to three cylinders help guys

[Taurus]

Problems once it's warmed up could be the coolant temperature sensor (CTS), the ECU defaults to a cold start mix (ie rich) and only leans the mix out when the CTS tells it the engine is warm. It's like when the old auto-chokes failed open, with a rich mix the engine can't burn the fuel properly and it bogs down. Lumpy idle, and hesitation are symptoms, also refusal to start when hot. A replacement CTS is cheap and they're worth changing from time to time anyway to keep fuel economy spot on, so it's worth checking that. A failing CTS doesn't always throw a fault code.

Check the plugs, if they're sooty and black then it's running rich.

If the plugs have white tips then it could be precisely the opposite - it's too lean. Which could be an air leak. When cold the rich mix is masking the lean mix so it only shows when it's hot. You'd know by the way it drove, started and idled - which we don't know of course. To track an air leak get it warm, let it idle, then spray something like Easy Start around the intake. If there is a leak it'll get pulled in and you'll hear the rpm increase slightly.

Another possibility (oh yes, with cars it's rarely straightforward) is the coilpack. They can fail as they warm up.

[kipp67]

thanks taurus ile give it a go funny thing is the plugs are sooty and white very strange but in the morning it puffs blue smoke out but onlt for a few seconds worn ring or oil seals

[Taurus]

A puff of smoke first thing that clears away is usually valve stem oil seals.

Take a photo of the plugs - it helps to see things.

[kipp67]

i would do but me cam bust seems that the electrode white on the tip but the 2 metal bits are sooty black

[Taurus]

I hope by "cam bust" you mean your camera is broken rather than your camshaft.

If the tips are white then I'd check for air leaks. It sounds like it's running lean.

[kipp67]

ok done the cts no change sprayed easy start around inlet manifold cant find any leaks