s2kboy03

hi wierdest thing happened to me today...i was filling up gas at the gas station...after i was done i start my car and then all of the sudden my idle goes up and down about 5 times for a few secs...it was wierd then i press the gas pedal for a sec then it goes back to normal...has anyone experienced this b4?? oh ya by the way my car is an 03 with around 25000 km on it...i think in miles around 15000 something...not sure exact

bigC

I've had a couple things like that happen to me. Sometimes in the morning when it's cold and I start the car right up and put it in gear the idle fluctuates on me until the motor runs for a few seconds. After filling it has happened before too. I don't think its anything to worry about. Have you had your oil changed recently? I changed mine about a month ago and it helped.

xviper

Exactly how are you shutting the car off and how are you starting the car. Some people will blip the throttle when they turn off the ignition. This is a throw back to the muscle car days. NOT good to do in a modern day fuel injected car.
When you start the car, do you have your foot on the gas pedal? If so, why? You should not be messing with the gas peddle for a start up, either. Doing so might confuse the ECU by giving it more TPS inputs than it really needs.
If you are not doing any of these things, then your ECU could still be having a hard time stabilizing the idle due to a number of reasons. It might be because it's running the air pump and adjusting to the O2 sensor readings. Your IAC mechanism might be acting up. Your MAP sensor might need a whack. Your ECU might need a reset.

Ooalloems2koO

dirty spark plugs could have been why........
and as u step on the gas u clear the dirt of the tip or some i heard

s2kboy03

i never said i pressed the gas pedal while starting it...i never do...it just started goin up and down for no reason without me pressing the gas pedal...my full tune up i did was at 23500 km which included oil change,spark plug change, tranny fluid change, diff fluid change etc and now my mileage is at 25500 km...could it something else making this problem?? it only did it once..now nomore

xviper

I never said you said it, so please don't get defensive. I was trying to get more information so as to make a diagnosis for you. Do you realize how difficult it is to figure out what's wrong with peoples' cars based on what they type over the internet? Do you realize how many times I've given a possible solution to a problem when not all information was given in the first post and then find out that the guy had some sort of mod attached to the engine?
Based on the few words you posted, I can tell you a dozen different things that you may have neglected to say that you may think is irrelevent.
I'm sorry that I even tried to make a guess. It won't happen again.

bigC

If its not happening anymore I wouldn't worry about it. If it occurs again try a MAP whack like xviper suggested, otherwise it doesn't sound too serious.

s2kboy03

i sorry xviper for getting defensive...and sorry for posting so little info...but i think its fine now..doesn't do it nomore thanks

xviper

I'm glad to hear that it was an isolated occurence. I'm sure it was simply an odd combination of conditions that caused it. If it should happy again, try to note those conditions so you can describe them. Then try the MAP whack and ECU reset to see if this resolves it. If it does, then a new MAP sensor might be a good thing to put on your wish list.

profpin

mine does that if i run the tank really low, reserve to almost completly empty.. i think its caused by air is picked up from the pickup tube.. once the air bubbles disappear, then the car idle normal again..