91 Camry - Extremely Rough Idle
 

Hey, I've had my car for about a year now and it has progressively been getting worse. It's not like the other cases I've read about the engine idle being rough after awhile- because it's only when I first start up the car/when it's cold. As soon as it's heated up and running for a while, the car runs perfectly. Also while the engine is running rough- the check engine light is on. It turns off as soon as the it's heated up.

I've had friends tell me they think it could be the cold fuel injector (whatever that is), the alternator, the wimpy battery, the starter (which I've replace)

I was just looking online for some more expert opinion or someone with similar problems- I'm a bit of a noob so any help is appreciated- Thanks!

If check engine light on, check for trouble codes.

This year of car has a built in code readout system allowing you to read out codes without a code reader.

https://www.camryforums.com/forum/ge...e-light-39644/

O hey thanks, I did just that and I got
12- Knock Control Sensor signal.
22- Engine Coolant Temperature Sensor signal.
43- starter signal

...From here, I just have no idea what to do, honestly. I put in a different (from another car) start in to see if it made an difference, and it really didn't seem to.

Suggestions?

Thanks

V6 or 4 cylinder?

You sure about code 12, this code is related to lack of signal from the distributor to the computer.

Water temp sensor = open or short in water temp sensor for computer.

Starter issue is not the starter but a 12V signal the starter circuit sends to the computer when the starter is engaged.

Given all the codes including 43 which is rare suggest a check for bad engine wiring.

Suggest you purchase a Haynes service manual for under $20 as this has the codes and wiring diagrams. Check with your library for info this car and photocopy or try the AutoZone website car repair section for this year and model of car.

The coolant sensor can be tested with an ohm meter. The distributor has a couple of sensor coils that can also be tested.

The starter code is just wiring.

Hrm, not sure if a knock sensor can cause a rough idle, but I would replace the sensor if that's what the readout says.

Also, how are your spark plugs? Have you changed your fuel filter?