Jim Grant's Tech Tips
‘90 Acura Legend. 2.7 L
Q: I own a '90 Acura Legend. 2.7 L. When I drive on the level road with any accelerating speed nothing happens. But when I drive uphill and accelerate, the engine light comes on and stays on until the ignition key is turned off. I have checked several components: Fuel pump pressure, Oxygen Sensor and Pressure regulator which all tested okay.
Before you do much more testing I would suggest asking the computer why the check engine light is on. After all, the early Acura systems were pretty simple with less than 20 possible computer codes. The first thing I want you to do is go under the hood of the vehicle and remove the alternator sense fuse for at least 10 seconds, it will be found in the main fuse box. Removing the alternator sense fuse in your vehicle will clear the computer's memory. The reason I want you to clear the computer memory? If you or someone else has been working under the hood there is no telling what kind of bad information may be in the computer. Once the memory has been cleared the vehicle needs to be test driven until the check engine light comes back on. Once the check engine light comes on you'll have to take up the carpet where your feet go on the passenger side, if your car is a coupe, or look under the passenger seat if it is a sedan. Why is that? That's where they hide the computer. That computer will have 2 blinking lights when the key is on. One is yellow and to be ignored, for it is used to adjust the idle speed. The light you want to watch is the red one. The red light will be blinking short blinks, long blinks and/or both short and long blinks. The blinks are indicating a computer fault code. Counting the blinks and referring to diagnostic information tells you what system the computer has a problem with. The computer in your vintage Acura is a very tolerant pile of silicone. If it is complaining, there's a problem! Start with the check engine light before you open the hood again.