Cold Start Issue

[hrm]

Hi Friends,

I'm having bit of issues when starting my car in the morning or whatever time when engine is cold. This is a Lancer CB2 with 4g15 carb engine. Have two problems actually.

1. when I crank the engine in cold it would start right away and rpm jumps to around 1300 for around 2-3 seconds and then comes back to around 300. Again the choke kicks in and rpm again goes above 1000 for a minite and again come down afterwards. Sometimes the engine stops unless I rev it for bit. RPM keeps fluctating like this until the engine gets heated up for normal operating temp. (To put it simply fast idling happens only time to time ) Once the engine heated up rpm settles around 700 and no issues afterwards. How to solve this? choke seems not working continuously.

2. Other problem is related to riding experience. I could hear engine knock when pressing on gas hard in mostly in 3rd & 4th gears. Have noticed this happens only after engine got heated up for normal operating temp and until that knocking will not occur. And I don't see any lag in pulling power nor other riding issues . What could be the reason ?

Note: I'm not actually sure whether this is engine knock sound. But the sound is similar when we try to press more gas when rpm is low for that particular gear.

Appreciate your valuable advices on this.

Thanks.

Edited December 26, 2012 by hrm

[hrm]

Could somebody shed some light please? It took much effort to start her today morning. engine fires up but stops in 1-2 seconds. manged to keep engine running after 4-5 times of cranking and revving hardly until the engine got heated.

[maheshw]

is seems your auto choke is not functionong properly in cold start & when was your last carb tune up? do you feel any miss in your car any time? also any adjustments on distributor ? have your recently replace the petrol filter?

Edited December 26, 2012 by maheshw

[MasterDon]

Yes check the choke mechanism.If the choke is ok and the problem persists try looking for cracks or gaps that could cause air leaks in the carb assembly and intake manifold.This is just a hunch by the way,there could be lots culprits causing the symptoms you've put up.Check the fuel and ignition systems and do a tune up before going any further.

[hrm]

Yes. Actually this all happened after a tune up I did some time ago. Everything was fine before that. I think the guy messed up with already working order choke. He cleaned distributor cap as well. Also there's a small miss in the morning.