Trouble Starting when cold

[Black_rainbow2003]

I have a 1999 Toyota Solara and recently since it's been cold there is a lot of trouble starting the car. It turns over fine and catches some times but wil not stay going. It's like the vehicle is not getting enough gas. After awhile the car will finally stay going but sputters and does not idle right. After the vehicle warms up the problem disappears. I also noticed a few months ago that when first started in the morning and going up a hill there seems to be a hesitation, again like the vehicle is not getting enough gas. Someone told me that it might be the flap that opens and closes that controls the amount of gas the engine gets. When cold this flap may stick. Does this make any sense?

Please help

Thanks

[99BlackSandv6]

They must have been talking about the throttle body. And no, I don't think that is your problem. It might be your IAC system. This system uses an electronically actuated valve to flow a certain amount of air past the throttle plate to keep idle steady or raise the idle to warm up the engine. It might be a fuel issue like a clogged fuel filter, maybe there is some water in the filter and that is restricting flow. As the engine bay warms up it will flow better like you said, and the problem will go away. It could be a number of things though. The IAC valve can get clogged with carbon build-up or freeze if condensation builds up on it. It sounds to me though that the problem is frost related. Stuff might need cleaned or your fuel filter replaced.

You could see if it starts better when you touch the gas peddle a little, not to the floor just barely on it. That would indicate the IAC is the problem. If that doesn't help, I would look closely at the fuel delivery.

[Black_rainbow2003]

Well today after mnay many tries the car finally went, sputtered alot but finally stayed going. Left the car idling for awhile and then drove around town. Worked great except seemed to idle lower than normal. Tried stopping and starting the engine again and turned over anc caught every time without hesitation.

How many fuel filters does the car have, I'm pretty sure there is one located in the gas tank. Is there another one? Could the IAC system still be the problem? I had an old 87 Corolla that used to act this way when it was really cold. I would just throw some gas in the carb. and way to go. Not sure what to do with fuel injection.

Any additional help would greatly be appreciated.

Thanks again

[99BlackSandv6]

There is a strainer, more like a sock inside the tank. There is also a filter on the driver's side in the engine bay. It is mounted on the frame, under the intake. Do you have a four cylinder or V6?

The problem could still be the IAC (Idle Air Control) valve. Try starting the engine when it is completely cold by pressing Lightly on the throttle pedal. If it starts easily then, have the IAC valve checked out by somebody. I figure that is the problem. When the engine finally starts first thing in the morning, does the idle go up to at least 1500 or so? It should at first, and this function is controlled by the IAC valve.

To condense what I said:
There is a main fuel filter in the engine bay under the intake tube.
The IAC is probably the problem.

If the car starts with part throttle applied and the engine cold, or the idle does not raise to about 1500rpm when cold, have someone check your IAC valve.

Also it would be a good idea to check the air filter. Just a thought.

[Black_rainbow2003]

Thanks so much for the info. I may have failed to mention when trying to start the car in the morning I do slightly depress the gas if she doesn't start at first. However this seems to make little difference. When she do finally start the RPM's are normal. No difference once she finally starts.

Just got back from driving around town and noticed that the check engine light cam on and will not go off. Could this be some sort of sensor causing my problem? Will a diagnostic check hooked up to the computer pick up the vlave problem you mentioned? The car is V6.

Thanks again

[99BlackSandv6]

Yes Check the CEL for sure, you'll get your answer.