Author Topic: troubleshooting Fuel Injection  (Read 2228 times)

Bengin

  • Newbie
  • *
  • Posts: 2
    • View Profile
troubleshooting Fuel Injection
« on: July 13, 2014, 12:52:14 AM »
owner of a 2009 (bought used last summer) now 2000 miles on it.  I have been experiencing some issues, the fuel or oxygen doesn't seem to feed properly when increasing the throttle regardless of the speed, thus losing speed and the scooter behave erratically at time.  According to the mechanic he believe it is fuel injection related, he ordered a T-Map sensor (part 39500)installed it and it wouldn't work, he then puts in the old one clear the error code and the scooter worked fine for a week, now the same initial problem have returned.  Has anyone experience similar issues, what needs to be done to fix this?

Thanks ahead of time for your help.

zombie

  • You never know do ya!
  • Hero Member
  • *****
  • Posts: 13870
  • Close enough to get the idea!
    • View Profile
Re: troubleshooting Fuel Injection
« Reply #1 on: July 15, 2014, 06:58:28 AM »
I don't get why the new one did not work but the old one did. Do you have that sensors fault code showing?

Are you sure it is a tMAP, and not a MAF sensor?

Has anyone tested the TPS voltage at idle? at WOT ? It should be near 0.5 volts at idle or just w/ the key on, and the engine off. I don't know the WOT value but the volt meter should show a smooth linear increase in voltage all the way to WOT.

Has anyone done a compression test? I know you said it ran fine again but that is always the first thing you should do.

One trick to verify something... Remove the O2 sensor wire, and hold it in one hand. Now put your other hand directly onto the positive terminal of the battery, and have someone start the bike on the center stand. If it runs fine replace the O2 sensor.
To bench test the sensor you will need a propane torch and a DVOM. The main idea is to connect the red lead of the meter to the black wire of the sensor, and the black lead of the DVOM to the body of the sensor.

Turn on the meter and set it to the lowest voltage scale, light the torch and place the tip of the oxygen sensor in the flame. Since there is no oxygen, the sensor will produce .9v or 9/10th's of a volt within 1 minute. This will indicate a rich mixture because the voltage is climbing. As you pull away from the flame,the voltage must drop within 3 seconds to it's original reading ,the voltage drop indicates a lean mixture.

If there is no reading or if the sensor voltage is not changing, then it indicates a bad or sluggish O2 sensor that needs replacing.

 Some O2 sensors have a heating element with more than 1 wire connected. Always connect to the black wire on the sensor to do the bench test.
« Last Edit: July 15, 2014, 07:00:42 AM by zombie »
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

Bengin

  • Newbie
  • *
  • Posts: 2
    • View Profile
Re: troubleshooting Fuel Injection
« Reply #2 on: July 15, 2014, 08:59:12 PM »
Thanks for your post Zombie,  Unfortunately I don’t know the error code; my mechanic didn’t write it down, (however he told me it was fuel injection related – from memory).

This time around when the problem came back the CELP light never came on either.  I did a print out of your comment and gave it to him; he will work on it the next few nights. I will advise of his finding.

Thanks

zombie

  • You never know do ya!
  • Hero Member
  • *****
  • Posts: 13870
  • Close enough to get the idea!
    • View Profile
Re: troubleshooting Fuel Injection
« Reply #3 on: July 16, 2014, 03:31:31 AM »
I hope it helps him.
 The components involved in FI are easy to deal w/. It's the ECU that is always a bitch. You have to eliminate/troubleshoot all the sensors first, and leave either the harness (more likely) or the ECU (less likely). I never trust the plug in diagnostic tool either. If there is an intermittent harness or ECU it will never pick it up.

The other things are a bad stator or rectifier/regulator. They can actually reduce current to a point where the whole system fails but still maintain 13+ volts.
« Last Edit: July 16, 2014, 03:33:51 AM by zombie »
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

CROSSBOLT

  • Hero Member
  • *****
  • Posts: 7764
  • West Tennessee, USA
    • View Profile
Re: troubleshooting Fuel Injection
« Reply #4 on: August 12, 2014, 08:46:43 PM »
Anybody tried to "INITIALIZE" yet? Also check the vent valve for the gas tank: they stick and cause all kinds of problems.

Karl
Karl

Three motorcycles 1960-1977 (restored a 1955 BSA)
Agility 50
Yager 200i
Downtown 300i
Navy tech, Ships Engineer, pilot and aircraft mechanic

An Error Has Occurred!

Call to undefined function split()