I have 50,000 miles on the vehicle, I had the right front fender, bumper replaced after an accident about 2 yrs. ago no engine damage, and I put in fuel injector cleaner about 5 times, and have just replaced the plugs with the same NGK plugs, but it still runs a little rough. What should I check next ?
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2006 Toyota Camry Question: Does anyone know why it runs a little ruff while idling, in gear, A/C- on or off ?
Answer #1patrick mannion from Greg Solow's Engine Room, April 28, 2009, 00:12Master
Does the engine idle "rougher" than it did when you first bought the car or is it just an observation that the engine seems to run a little rough with electrical loads or air conditioning turned on?
A 4 cylinder engine will always be a little rougher than a 6 cylinder and a 6 cylinder will always be a little rougher than an 8 cylinder. The more cylinders the more even the engine will idle.
The engine should idle at about 650 to 725 RPM. The idle speed is controlled by the throttle control motor which the computer in your car sees electrical loads, power steering being turned or air conditioning turned on and should compensate by raising the idle speed. A slight vacuum leak could cause a rough idle but not be bad enough to turn on the Check Engine Light. Probably need to plug in a scan tool verify idle speed and see if any data stream information shows a clue as to what is going on.