Car is a 1997 Honda Civic EX, 1.6L 4 cyl, 5 spd, ac, power, 187k mi.
November, 1, 2007 AT 2:44 PM
Start checking the TPS (check the voltage with the wide open throtle)
Then the EGR for carbon build-up (clean it)
And the Maf sensor.
The Mass Air Flow sensor is crucial to the fuel systems operation. This is the sensor that the engine computer uses to measure how much air is entering the engine so that it may properly deliver the proper amount of fuel. A dirty MAF sensor hot wire may cause several problems to include: difficult start, poor acceleration, pinging, rough idling, to name a few. This whole procedure should take you less than ten minutes.
Its the check engine light on?
Check them and get back with the results.
I l get some info on the how to and I ll post it later if you don t know how to test the sensors.
BTW I saw that you donate!
Thanks a lot! We appreciate that!
November, 2, 2007 AT 11:15 AM
Yes, thank you for the info I was thinking of the mass airflow sensor too! And no check engine light.
November, 2, 2007 AT 12:31 PM
In this case your car uses a MAP sensor (Manifold Absolute Pressure)
a MAP sensor simply compares the pressure difference between 2 chambers. One chamber is sealed and used as the reference pressure (usually a vacuum) and the other chamber is connected to the intake manifold (usually by a vacuum hose). When the pressure in the intake manifold changes, this will change the voltage signal going back to the ecu from the MAP. A pressure drop will cause a voltage drop. This voltage is only interpreted as manifold pressure. The ecu will also need to use the signals from the rpm sensor and air temp sensor to calculate air mass, pressure alone is not enough. Plus any vacuum leaks on the hose, or indeed any other vacuum leaks on the manifold, will affect this sensor's signal.
After locating the MAP sensor, disconnect its wiring harness.
To test the MAP sensor, run jumper wires between its terminals and wiring harness per the service manual's instructions. Turn the ignition to the ON position and take a voltage reading. Spec for this MAP is about 4.5-5.0 volts.
With the engine running and warmed up, take another voltage reading. It should differ from the non-running number and fluctuate when the engine is revved. If not, verify that the vacuum line isn't damaged or blocked.
If the vacuum line checks out, the sensor is likely faulty. Replace the bad MAP with a new one by connecting the vacuum hose and wiring harness, then securing the sensor to its factory location.
I would check for vacuum leaks and check the sensor good.
Let me know how are you doing!
November, 3, 2007 AT 1:36 PM
I'll take a look at all that, thanks for all the great info it's really helping me understand fuel injection.
November, 8, 2007 AT 7:39 PM
Hello again, when I take the voltage reading I am getting nothing. To make sure I'm doing it right do I take the reading from the two terminals of the female plug? And is it left unplugged while taking the reading? This is what I am doing. And to also be sure the MAP sensor is located on the fuel injector rail yes?
November, 8, 2007 AT 7:41 PM
Forgot to mention that the car runs perfect when cold then bogs down a few minutes after running.
November, 8, 2007 AT 8:11 PM
How are you been?
Well lets continue, i think that its working good when cold because of the cold start valve (extra fuel when cold)
here a picture of the MAP sensor:
the complete picture:
I ll be back with the spec.
November, 8, 2007 AT 8:35 PM
You should run "jump" wires to the MAP sensor to be abble to get readings here is the spec: