Hey, i have a 2011 kia forte koup with the 2.0. I have been having a problem with it where when i disconnect and reconnect the battery the car will not run properly. When i try to start it, it will start up but runs extremely poorly like it with sit there and jump from 500 to 1500 rpm over and over and runs very rich. The first time i had this problem it gave me a check engine like for the map sensor or the o2 sensor. I changed out the map sensor and spark plugs but it did not fix the problem then it just started running normal after a few days. Its been running good for a couple of months but i recently had to remove the battery again and now it is doing it again but this time its not bring up any codes. Just wondering if anyone know why this might be happening. Thank you.
Disconnected battery now car doesnt run
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EFI cars can get very cranky if the battery and charging system isn't 100% stable.
Have you a: checked the battery condition? voltage, specific gravity etc; and
b: is the alternator actually charging the battery properly? Put a multimeter/voltmeter across the battery when the engine is off and you should see around 12.5-12.7 volts. Now start the car and watch the voltage - it should come up to 14.3-14.4 volts. If it's under that or over that the alternator is likely in need of replacing.
If you see the voltage jumping around from say 12.5 to 14.4 to 13 to 14.4 to 12.5 etc when the RPM is fluctuating it could be a sign that the voltage regulator is cactus - it's part of the alternator, so the alternator would need to be replaced.
Also check the battery cables themselves - check where cables join to the battery terminal clamps, check the negative battery lead where it connects to the chassis (it'll be within 1-2 feet of the battery usually), check the earth strap from the engine to the chassis as well. If any of those are loose or corroded it could cause weird problems
(explainer: The ECU is looking for specific voltages from either MAF or MAP sensors, O2 sensors and so on - if the voltage going to the sensor is wrong, then the voltage coming out will be wrong. Fuel injectors are also usually designed to run at 14.4V - feed them too little or too much voltage and they will under- or over-fuel due to the solenoid activating differently. Low voltage will also create a weak spark in the spark plugs resulting in unburnt fuel, rough running etc)
Have you a: checked the battery condition? voltage, specific gravity etc; and
b: is the alternator actually charging the battery properly? Put a multimeter/voltmeter across the battery when the engine is off and you should see around 12.5-12.7 volts. Now start the car and watch the voltage - it should come up to 14.3-14.4 volts. If it's under that or over that the alternator is likely in need of replacing.
If you see the voltage jumping around from say 12.5 to 14.4 to 13 to 14.4 to 12.5 etc when the RPM is fluctuating it could be a sign that the voltage regulator is cactus - it's part of the alternator, so the alternator would need to be replaced.
Also check the battery cables themselves - check where cables join to the battery terminal clamps, check the negative battery lead where it connects to the chassis (it'll be within 1-2 feet of the battery usually), check the earth strap from the engine to the chassis as well. If any of those are loose or corroded it could cause weird problems
(explainer: The ECU is looking for specific voltages from either MAF or MAP sensors, O2 sensors and so on - if the voltage going to the sensor is wrong, then the voltage coming out will be wrong. Fuel injectors are also usually designed to run at 14.4V - feed them too little or too much voltage and they will under- or over-fuel due to the solenoid activating differently. Low voltage will also create a weak spark in the spark plugs resulting in unburnt fuel, rough running etc)
Yep. Toyotas are like that too - won't idle right after losing battery power, which is lots of fun when it's cold, the battery dies, and you have to be somewhere, so you jump it, get on with your day, and it stalls at a light and won't restart. Happened to my buddy yesterday. I had to basically jump him at every other light so he'd make it home.
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Don't buy sensors & modules from Chineseium sellers. Autozone, Pepboys, Advanced Auto, Carquest, Napa, O'Reillys & online. They all sell sh!t Chineseium pos parts. Made for throw away & not for quality.
Go to your local Kia/Hyundai dealership & buy the required sensors & modules from them.
The local salvage/junk yard for that "I need it now bandaid aide oem/factory till payday" parts
Kiapartsnow.com is an authorized Kia/Hyundai online store.
Go to your local Kia/Hyundai dealership & buy the required sensors & modules from them.
The local salvage/junk yard for that "I need it now bandaid aide oem/factory till payday" parts
Kiapartsnow.com is an authorized Kia/Hyundai online store.
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