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Discussion Starter · #1 ·
Hello,

One of my cxt500 turbos was running very poorly under 3000 rpm. After researching the problem on the forum, I purchased a used PB sensor off of ebay. about 3 hours of labor to replace the sensor and the bike runs very well. The Idle is now a little high but that was expected as the previous owner tried to adjust idle to correct it.

Thanks for all the good info:D

I did buy some Suzuki sensors but I have not received them yet so I just put in the original sensor. If I run into this again on either of my 2 turbos, I will use the Suzuki fix.

Thanks all

JPS
 

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I have a similar problem with my Turbo but it does not seem like enough of a problem
that I should need to fix it. Going from idle and gently opening the throttle the bike will stutter
very slightly, if I rip the throttle open there is no stutter. Occasionally, at very low speed the bike
may misfire. Is that what you are talking about??? Tell me more about the Suzuki fix.
 

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Discussion Starter · #3 · (Edited)
I have a similar problem with my Turbo but it does not seem like enough of a problem
that I should need to fix it. Going from idle and gently opening the throttle the bike will stutter
very slightly, if I rip the throttle open there is no stutter. Occasionally, at very low speed the bike
may misfire. Is that what you are talking about??? Tell me more about the Suzuki fix.
My symptoms were as follows.
  • At times the bike would run and idle normally below 3000 rpm.
  • If you crack the throttle, you could bypass the erratic behavior
  • Sometimes while riding, when coming to a stop, it would not idle and die
  • Sometimes rpm would vary between 800 to 2000 erratically when idling
  • Sometimes you would need to nurse the throttle at idle to keep it running
  • I personally did not experience any misfire/backfire. but have only had bike a short time

I have read elsewhere on the forum, (and agree), that this condition causes the bike to run lean below 3000 RPM. With a bad sensor input, I believe the ECU tends to run the bike lean at idle, then when the bike is about to die applies more fuel. This would cause the erratic rpm behavior.

I thought I read somewhere, but could never find it again, a troubleshooting procedure that stated if you disconnected the pressure hose to the PB sensor, the ECU would sense a failure and use a default pressure value. In this case, the bike would idle fine, but a fault would show up on your display. I did not do this procedure because after all the research on the forum, I was convinced that this was my problem. I went for it and it worked.

NOTE- The MANUAL, also shows there are jets in line with the sensors. It gives a procedure on how to remove the jets and clean them. A clogged sensor jet could also have the same effect.

Regarding your question on the Suzuki sensor.

New modern sensors from Suzuki have been found to replace the Pb and P1 sensors. (this happened around march 2013) Numerous folks have done this with positive results. If you search the form for the following thread, "Pb-sensor replacement", it documents all the information you would need. It gives you the part numbers of the sensor and mating connector. One member chose not to use the mating connecter and gives detailed instructions with pictures on how he added a connector to the sensor to plug right into his bike. NICE JOB.

http://cx500forum.com/forum/cx500-cx650-turbo-forum/17499-pb-sensor-replacement.html

Also, the link below shows information posted on the TMIOA page. This shows a lot of the same information, but also shows how to use the female connector and the connector from your BAD SENSOR, to make a mating adaptor harness for the Suzuki sensor. shows the wiring diagram. NOTE- BE SURE TO SCROLL DOWN TO SEE THE INFORMATION ON THIS PAGE.

http://www.turbomotorcycles.org/TMIOA/TechHelp_Honda_PbSensor.html

Of course, do not forget the WIKI. If you go to the cx500t section it also discusses this.

http://cxgl.wikispaces.com/home


As someone else on this form said "If you have any functionality issues below 3000 rpm, suspect and replace the PB sensor"

Hope this helps somewhat:cool:
 

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Discussion Starter · #4 ·
I also came across this info in my notes:

spark plug 1) This may seem elementary, but have you checked or changed your spark plugs? (Always run NGK Iridium)
Old spark plugs can cause an RPM stutter, and so can a weak battery. (Been there on both counts)

Not sure where I got this info but it may apply to you.
 
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