runs poorly when cold

[VLACS]

hey guys.

my car is just running like **** when its cold. stalling and so on.
the anoying part about it is if i take it to the mech it doesnt do it. which anoys the hell out of me.

its got a really inconsistant idle. it fluctuates alot.

any ideas there.

cheers

 

[Jules86]

i had a prob with my fuel, when i used to start my car if it did start it would idle rough and drop out, is it only when cold or just assuming? i just flogged the **** out of my car with some good fuel and it fixed itself. Guess it could be anything though.

 

[vlrad]

My car - I change things all the time between A car and B car - A's the running car.

I changed computer and afm and now the idle is a little high and I can feel it miss at lights - only a little.

My theory is it is running a little rich - this is because at night when it gets more cold air to fuel it runs well.

 

[Bucket]

mate have you touched anything of note before this?

Does it run as per normal when warm?

 

[VLACS]

My car - I change things all the time between A car and B car - A's the running car.

I changed computer and afm and now the idle is a little high and I can feel it miss at lights - only a little.

My theory is it is running a little rich - this is because at night when it gets more cold air to fuel it runs well.

can i borrow your b car?

bucket - i put in a cold air intake. i should check the afm connectors as i took the pipe out from the Tb. cant say ive touched anyhing else other than that though. im getting a o2 sensor soon. would that have any effect on the idling. im getting a load of black **** on the back of my car.

 

[Bucket]

bucket - i put in a cold air intake. i should check the afm connectors as i took the pipe out from the Tb. cant say ive touched anyhing else other than that though. im getting a o2 sensor soon. would that have any effect on the idling. im getting a load of black **** on the back of my car.

Did you take the by-pass hose off? Are you getting any air leaks at all around the intake hose, if i move mine much she runs like a $2 Ho due to tiny leaks at the throttle body.
Make sure the intake hose is air tight and theres no leaks from vacuum hoses you may have moved, that will cause it to run like poo. Infact, take a vacuum hose off somewhere and see if idle is worse, you may have a leak somewhere. Check the PCV hose in the middle of the rocker cover and the other one at the back to see you havent cracked them.

The o2 sensor, the computer runs in closed loop on a pre-set mixture till she warms up and the o2 takes over, mine wasn't working for ages but when its warm, unplug the o2 sensor and see if the car runs any worse, thats my o2 diagnosis tool.

 

[vlv8vic]

as above. as well, if your thermostat isnt closing it can cause a few little bitches when the engine is cold.

 

[Bucket]

my thermo wasnt closing, that just causes the car to run cold for longer and a bit more fuel usage, shouldnt be a drama.

 

[VLACS]

yeh. hispeedvp told me that i probably need a new o2 sensor cos of all the black **** on the back of my car. its getting really bad. like i wash it then its balck after a drive. but any ways.

which one is the vacuum hose
ill try dsconneecting the o2 sensor.

 

[Bucket]

mate the two rubber hoses comin off the top of the rocker cover, if they are cracked your idle will drop. My front one now is garden hose, the rear is 10mm clear nylone hose - SHMICKO!

As for the black smoke around the exhaust, check the AFM again to make sure.

o2 sensor, when its disconnected and the car is in drive with the brake on, the car will run like its missing one to two cylinders and if you sit there long enough, you'll smell the rich exhaust. Stand at the exhaust and see if it makes little popping sounds every so often... thats what mine was doing when o2 was gone.

AFM out of whack will really give you the rich, black smoke crap.