85 Celica GT check engine light on

[dewd]

Greetings Folks,

My 85 Celica GT, 2.4L 5 speed runs for a few miles from a cold start and then the check engine light comes on.

The engine seems a little sluggish but I don't notice a definite miss like a bad spark plug.

Can you tell me where to start to try and pin down the problem?

Many Thanks^2

[toyomoho]

Pick up or find service info to learn how to download the codes using the cars own readout system. This would be in the form of a flashing LED or light. A library may have service data such as from Motor.

[stepho]

I have put some service data here:
http://ourworld.compuserve.com/homep...pho/eng20r.htm
Get the Haynes Celica RWD manual - it covers everything you need in these situations.

Hard to guess from the few symptoms given but check for things like dirt or water in the fuel filter, low water, low oil, rust in the fuel tank (blocks the tank filter), vacumn hoses coming off.

- Stepho

[dewd]

I got the codes from jumping the Check Engne Connector and watching the flashing Check Engine Light.

The first time around I got a "6" and "12", 6 flashes, a pause, and then 12 flashes.

Afterwards, I disconnected the battery to clear the stored codes and then reconnected the battery and drove til the Check Engine Light came on again.

This time a get a "12" from the flashing Check Engine Light and NO code 6..

Can you tell me what the code 12 means on the 85 Celica? Or the code 6?

Is there somewhere on the web to get the code definitins for an 85 Celica?

Thanks^2 for your help!

[tonyconvert85]

Code 12 is usually a bad knock sensor or its wiring. I havethe same problem. I tried used knocks sensors, but the problem persist. Other people report that their problem ended when they bought new ones. I also need to see if the computer is recieving signal. I'll keep u posted or let me know if you solve the puzzle. This sensor is located under the fuel injection system (the plenum). It's next to the oil sending unit or the fuel filter.
Tony

[dewd]

Hey Tony,

I didn't do anything yet. I guess I'll go after the knock sensor. First, I have to figure out how to diagnose it.

Thanks to everyone who offered some input.

[tonyconvert85]

Let me know about your final results. Hopefully when you find the solution to your problem, I'll find mine. I want to try the newer knock sensors:86 and up. I'll keep u informed or viceversa
Tony