[Corsa B 1993-2000] Engine performs better when cold

[krazeddd]

I have a little x10xe nothing special i know but ive done what i can to get the most power out of it I can.
So i've blanked off the EGR and got rid of the centre baffle in the exhaust (sounds nice to be fair)

Anyways, since owning the car i've replaced the idle control valve, air mass meter, tps, crank sensor, and cleaned the throttle body out and a coolant temp sensor

It has always been quicker when the engine is cold but i just dismissed the fact it did.

Anyway a few days ago i replaced the timing chain and oil pump, and now when its cold its like driving a completely different car, so much more power in every gear (i suspect it wasnt as quick before i did the timing chain because the valve timing was slightly out)

anyway does anyone know why? i'd love it if it is as quick as it is when its cold, all the time.

also when its hot it sometimes starts on 2 cylinders and works its way onto 3, but if i blip the throttle abit whilst starting its straight onto 3

cheers

[Danny]

Engine performs better when cold

Could be the coolant temp sensor. They're a very common fault. When they fail, it tells the ECU that the engine is cold when it's hot, and therefore over fuels it causing bad running.
Nevermind I missed that you've already changed it.

[Taurus]

Possibly because when cold it is running a rich mix, but when hot the mix is leaned out. It would be worth checking there isn't an air leak in case it's too lean when hot, or monitor the O2 readings on Ofcom when warm.

[krazeddd]

Possibly because when cold it is running a rich mix, but when hot the mix is leaned out. It would be worth checking there isn't an air leak in case it's too lean when hot, or monitor the O2 readings on Ofcom when warm.

never thought of an air leak as my brakes are a bit rubbish to be honest, any common places to look for them? cheers

[Taurus]

Check all the vacuum pipes, incl. the servo pipe and servo itself. Check around the inlet manifold and anywhere after the air flow sensor. Any air getting into the system that isn't metered will cause it to be lean.

To check the brake servo is working - with the engine off press the pedal several times to exhaust the vacuum. Then hold the pedal down and keep it held down whilst you start the engine. You should feel the pedal dip slightly as the vacuum is established.