I have an 04 Lancer Ralliart, the only mods that I have are: SRI and Joe's Underdrive Pulley. I have noticed that if I disconnect the battery, reconnect and let the car idle the RPM's fluctuate. But, not only that, the battery light and the brake light will flicker. It will run this way for a while and want to die. Even when driving the car around it will do this (only for a little while though). A month later it is starting to do this again and all the time. The headlights will dim at a dead stop and the car wants to die. When you start to move again everything goes back to normal. Then when you stop again, it starts to act up. I dont know what it could be?? Does anybody have some ideas??

 

This is an easy one, it's the underdrive pully. The alternator doesn't put out the same power with the underdrive pulley since it is smaller. As for the fluctuating RPMs, there is no problem there and the car is just getting used to the idle. In the end, what I am saying is it doesn't sound like you have a big problem but if it bugs you replace the stock pulley and everything will be back to normal!

 

Why would this problem start now, I have had the pulley on the car for a year or two?!?!

 

Hmmm.... Good question. Possibly you have alternator problems? That could also be the cause of what you are describing. You could replace the pulley and see if that fixes it. Or you could just take it in. But from what you've said it sounds like an alternator problem to me. Check the belt, make sure everything there is ok.

 

That is what I am planning on doing. I just think that it is weird that the battery light and brake light will flash off and on periodically. We will see. Anybody else have any other ideas??

 

not sure of the brake light, you may have a short somewhere.

the most likely thing, however, is your battery is old and needs to be replaced. has it been getting colder lately? colder weather will kill batteries like nothing else. this could very easily be the solution to both your lights and near stall problems

 

yeah, it has been raining a lot. I tried to look for the expiration date on the battery, but I didnt see one. I will probably take the battery off and have it tested, along with the alternator. My wife drives it and I asked her if it does it all of the time or only with the lights on? Only with the lights on... so I am thinking, maybe alternator?? I hate it when a car has electrical problems, it is always a hit or miss.

 

especially with the udp you need a strong battery. the autoparts store will be able to test it under load and tell you if it's bad.

I have noticed that mine is starting to get a little weak at times, especially since it's getting colder. it's OEM.

 

^^^ If its been raining a lot lately then a short is very possible as well, like dan said.

 

What you described happed to one of my older cars. It turned out to be the battery like DD stated. Sounds like it is not holding a charge very well. Especially when you say it runs fine at operating speeds.

 

I wouldn't say a short but high resistance considering rain and cold whether. Which will make your battery and alterantor work harder. Causing RPM to jump up and down. I would check your charging system and look for any corrosion or signs of wetness which is bad. Using anti-corrosive paste will keep water away from connections also. Making your charging system live longer...

 

I havent been able to have the battery or alternator tested yet. But, my wife told me tonight that while driving at night w/ the lights on and the radio on it doesnt do it. When she turns on the defroster the car will start acting up and want to die.

 

There should be a circuit connected with the ECC. Increases idle to adjust to the higher load put onto the motor. I can't really give you an answer unless I was there to diag the car. I can try and help as much as i can. I would first start out but checking the charging system then doing a data stream on the car. See if everything is within spec. If you have any questions feel free to PM me.

 

I am going to start working on it tomorrow. What is ECC??

 

Electronic climate control