Why is it run rough when it sit for more than 24 hours.

LPEARCE1

MEMBER
2003 CHEVROLET VENTURE
170,000 MILES

I too have the problem with my 2003 Chevy Venture, Have had the cat converter check, it is good. Had plugs and wires done, replaced the intake gasket, did a fuel system cleaning. Replaced both O2 sensors. Even took it to a chevy dealer, they said that a cat converter may or maynot fix the problem. Then on monday when it was raining so bad from the Tropical Depresson Lee, it ran real horrible. Usually it will settle down after a few miles, but this went on for about twenty mins, all I could do was to feather the throttle and keep it moving. I am at a loss for what is causing the problem. And I do not have the money to replace parts that may or maynot fix the problem.

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,289 POSTS

Based on what you described, something with the ignition is getting wet and causing the rough idle when cold. When it gets hot, it dries out and runs better.

Here is a little trick I want you to try. When it is dark, start the engine, open the hood, and mist water on the coils, wires, plugs. On the entire ignition system. Then in the dark, if there is a problem, you will be able to see an arc. Where the arc is located is the problem.

If you're on the east coast (or near), I've seen the news. WOW! I'm near Pittsburgh. We've had rain, but nothing like what you are seeing. My sister is near Lancaster, PA and they are having all types of problems. Good luck with everything and I hope what I said helps.

Joe