2000 Yamaha 150 HPDI intermittent rough idle

bassman3112

Member

• Dec 28, 2010

• #1

I have had a problem with the idle on my HPDI. Sometimes, not everytime, after startup the motor will miss after putting into gear. After several re-starts it will loose the miss and take off like mormal. What can I look at before taking to the dealer?

 

justintime

Silver Medal Contributor

• Dec 28, 2010

• #2

SPARK PLUGS
CHANGE FUEL FILTER
DRAIN vst, IF YOU SEE DEBRIS vst filter needs changing
o2 sensor cleaned

 

bassman3112

Member

• Dec 29, 2010

• #3

Thanks for your reply justintime,
Spark plugs and fuel filter have been changed. Where is the o2 sensor located, and if I find debris in the vst, how easy is it to change the filter...I assume it is inside the vst???? By the way, what does vst stand for????

 

justintime

Silver Medal Contributor

• Dec 29, 2010

• #4

Vapor
Seperator
Tank

#51 o2 sensor

 

bassman3112

Member

• Dec 29, 2010

• #5

Thanks a bunch. I will let you know if this corrects my problem.

 

justintime

Silver Medal Contributor

• Dec 29, 2010

• #6

shoot me that email

 

bassman3112

Member

• Dec 30, 2010

• #7

Would it be okay to do a Seafoam treatment sprayed into the air intakes since this engine has injectors and not a carburator?

 

B

boatwrench42

New member

• Dec 31, 2010

• #8

Yes. Remove the prop and run engine in gear so engine runs on all 6 cylinders while doing so. You'll get a mess on the ground so be careful where you do it. Probably not a fuel filter issue, that usually shows up as a high speed problem. Possible O2 sensor but I rarely see those fouled any more. Pulling the VST or O2 sensor is a bit of a challenge for the average boat owner. Throttle plates not sync'd and wrong TPS voltage can also cause this problem.

 

justintime

Silver Medal Contributor

• Jan 1, 2011

• #9

NO NO NO!!!!!!!!!!!!!!!!!!!!!!!!!

use the fuel fitting on the motor

you can foul the Intake temp sensor