enter image description hereSo, Last year my 94 Acura Integra AT passed emissions by the skin of its teeth, this year it won't pass, I have noticed in past year and half that dropped from around 30mpg to about 15mpg. Some times last year I would be parked idleing and everything would be normal, car would just shut off for no reason. Also when I start the car you can tell it is dumping fuel as the engine shakes and has rough idle on start, sometimes it takes more then 10 seconds to start when turning the key. I have replaced everything on the car but the ECU, I have the following new:

  • Catalytic Converter
  • Spark plugs
  • Plug wires
  • Distributor
  • Fuel filter
  • Fuel pressure regulator
  • Injectors
  • TPS sensor
  • Ambient air temp sensor
  • O2 sensor
  • Complete intake clean and new gaskets
  • New air filter
  • Pcv valve
  • IAC
  • New timing belt and timing adjusted accordingly
  • Valve adjustment to OE spec

And whatever else there is.

  • Welcome to Motor Vehicle Maintenance & Repair! If you have the data on the emissions readout, that may be helpful in diagnosing your issue. From your huge drop in fuel mileage, I'd assume your HC's are out of this world. – Pᴀᴜʟsᴛᴇʀ2 Nov 16 '17 at 15:42
  • CO levels are too high. – Brandon Beecher Nov 16 '17 at 15:57
  • Have you read your codes? – GdD Nov 16 '17 at 16:22
  • OBD1, did paperclip method and no codes. – Brandon Beecher Nov 16 '17 at 16:23
  • @BrandonBeecher - Yes, but what were the numbers? All three, not just CO. – Pᴀᴜʟsᴛᴇʀ2 Nov 16 '17 at 16:37

Does it show a check engine light (CEL)? Search for Integra CEL ECU Codes and you will find instructions to show any system codes and take appropriate action.

If you aren't getting a CEL then replacing the ECU won't hurt. Very weird symptoms could be ignition or fuel. Difficult to imagine what else it could be based on what you've already done.

The next step is to get the factory service manual and test all the sensors for operation within specification. Just because parts are new doesn't mean they are operating within spec.

Good luck!

  • No CEL, I don't know why an ECU would fail if it's not getting wet or something to damage it. – Brandon Beecher Nov 16 '17 at 15:55
  • Vibration can damage it ... – Solar Mike Nov 16 '17 at 20:45

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