i have problem with my lancer engine. the engine code is 4G67. my engine just arrived from overhaul, but i still have some problem on it.
1. when i start engine in cold condition (first start on a day), there is black smoke emitted from exhaust. when the temperature increase the smoke dissapear.
2. when i push the accelarator pedal rapidly there is heavy black smoke from the exhaust, this happen in cold or warm engine. but when i push the accelarator pedal slowly there is no black smoke.
3. poor fuel consumption. before overhaul my engine fuel consumption is about 7km/l (city) and 9km/l (out of city), but now the fuel consumption is only 4.5km/l (city) and 6km/l (out of city). i have to fuel 7-8 times full tank a month, this cost me a lot.

my engine came with new air filter, fuel filter, oil filter, and fuel tank cleaned already. all i have done is to checked air intake temp sensor, eng coolant temp sensor, throttle idle position switch, throttle position sensor and all is good.
for egr system i checked egr valve and thermo valve individually all good, but i dont know how to chk egr system completely. i dont know when throttle body gives vacuum source to open egr valve.

any suggestion please? your help is very appreciates, thank a lot.

 

There is nothing wrong with the engine.

Sounds like an o2 sensor

 

I agree, the black smoke indicates a rich condition. If you're not force induced, then it's most likely your o2 sensor gone bad. You can also have a bad EGR system.

 

i have a big problem. i have a 95 eclipse gs. cold air intake and header pipe with greedy exhaust/muffler. the problem is that the car will not stay running on its own. i have had a new fuel filter, fuel pump, crank case position sensor, and egr valve. what could be the problem

 

Ok first of all make a seperate thread.

Now... in that thread answer me this question... what do you mean by "will not stay running on its own"?