Recently bought an '89 200TQ with only 113k mi, 5-spd, excellent condition. At about 3000rpms under acceleration in all gears, the check engine light comes on. I live at 6600' altitude, use 89 octane gas. Michelin man hose is tight and solid. Any ideas why the light is coming on? Kinda scary when climbing mountain grades and watching that orange light staying on. Might I hurt the engine?

1. Engine is knocking for some reason

2. More likely: intake air temperature sensor resistance is out of spec. One possibility is broken wire to the sensor (BTDT on a 10V @ sea level). Check for a broken wire under the rubber boot that covers the air temperature sensor connector.


Suggestion: Pull engine fault codes.

Try higher octane gas...

Pull fault codes. If it's the IAT it'll throw a code for it...

Steve
Michigan

Since I just recently bought my 200TQ, i'm not sure what you mean when you say "pull fault codes." How do I do that? (I know about the built-in diagnosis system, but how can I check fault codes at home?)