Starting Issue

[Anthraxnz]

when i start my car after its been sitting outside all night it runs really rough.
it just started doing it just recently normally it would just start straight away.

when you start it, it will crank for a bit then slowly come to life running rough until i push the accelerator and give it a bit of a rev.

dad thinks it could be the choke, i dont know how the choke on an EFI works so i have no idea.

anyone had a similar problem?

cheers

[Cogez]

my car had a similar problem just before it died completely =P, a new engine fixed my problem.

EFI engines don't have a choke either, the fuel/air mix is controlled by the computer

[Morton]

For a start, your dad is wrong

Sounds like either:

a) leaky injectors causing a few cylinders to flood overnight, leading to hard starting

but more likely:

b) a fouled inlet manifold or head gasket, causing oil or water to enter a few cylinders overnight, meaning when you start in the morning things are a bit lumpy and far from ideal. It won't run smoothly until you rev it, because doing that is blowing the crap out.

Get a compression test done as soon as possible, or if you're a little mechanically confident, take off your inlet manifold to check for breaks in that gasket, because it's far more likely for an inlet mani gasket to go than a head gasket. As a general rule, you have to do something seriously wrong to blow a head gasket on holden motors.

[Anthraxnz]

i had suspected a gasket of some type and that water or something is entering the clyinders. im replacing the water pump and thermostat on the weekend, so ill take a look at it then.

ill see if my mate can do a compression test at his shop.

cheers

[Morton]

When you next start it up cold, check for an excessive amount of white or other smoke from the exhaust. More than the usual cold startup mist. This would indicate coolant burning off Also, if things get desperate, leave your car for 24hrs, then disconnect the fuel pump fuse, unplug a spark plug and injector, and crank the engine over with some paper towel over the spark plug hole and see what comes out

[Anthraxnz]

im going to do my inlet gaskets this weekend with a bit of luck. i've got a haynes manual or a gregories cant remember which one. but it has detailed instructions in it.

i also found a way to lessen the amount of water entering the chamber, by cooling the motor down (using the thermofan bypass swtich) to about 1 bar on the temp gage (OP temp is about 1 Bar) it starts better.

before i started doing that the temp would be around 3 - 4 bar due to the hilly mission i go on to get home. heating the gaskets and making them expand.

[Anthraxnz]

update:

i have noticed coolant around the inlet gasket on the left cylinder bank along with oil. does the confirm a damaged inlet manifold gasket?