Engine dies off Idle

[Wolfman460]

I thank you all for you advice. The fuel pump buss is a noice I know well. The hiss was not from it. I figured it could have been a pinched vent tube though. With the tank lifted a bit, and all hoses free, the motor would still not start. I checked the TPS using the onboard diag.. Is that system, not enough to tell? I watched the numbers go up and down with a twist of the throttle. The numbers given off by all sensors that are checked by the onboard diag. were within the perameter set by the shop manual. I am thinking about using a multi meter on the tps, to double check, and the crank position sensor as the onboard diag. does not check it. As for the fuel additive, it is in the fuel already. I added it when I last filled up. (ie. Startron, and STP inj. clnr.) If when I check, the CPS ( crank position sensor) reads fine, I will know of nothing left but to take it to a tech. I will also check the caps on the trottle body, as I had sync.'d them about 5 mths ago. If there is any more advi., it would be appreciated. BTW: the battery checked good, is fairly new, and goes on a trickle while stored.

 

[PA1195]

I thank you all for you advice. The fuel pump buss is a noice I know well. The hiss was not from it. I figured it could have been a pinched vent tube though. With the tank lifted a bit, and all hoses free, the motor would still not start. I checked the TPS using the onboard diag.. Is that system, not enough to tell? I watched the numbers go up and down with a twist of the throttle. The numbers given off by all sensors that are checked by the onboard diag. were within the perameter set by the shop manual. I am thinking about using a multi meter on the tps, to double check, and the crank position sensor as the onboard diag. does not check it. As for the fuel additive, it is in the fuel already. I added it when I last filled up. (ie. Startron, and STP inj. clnr.) If when I check, the CPS ( crank position sensor) reads fine, I will know of nothing left but to take it to a tech. I will also check the caps on the trottle body, as I had sync.'d them about 5 mths ago. If there is any more advi., it would be appreciated. BTW: the battery checked good, is fairly new, and goes on a trickle while stored.

There are others here that know more than I about the TPS problems from personal experience - I've just read about them before here, plus in the Service Manual. I'd put the multi-meter on the TPS per the Manual and check to see if the output voltage is correct and changes smoothly from idle to open. Any brief lack of output voltage would cause suspicion. Others may have a better test. You might try to get a replacement and see if parts swapping helps. They do go bad and apparently act like you described. Sounds like you've covered most other bases except the vacuum. There's also a big master electrical connector others here have had corrosion issues with that lies up in front of the engine or ???. See the concurrent TPS topic. Clicky

 

[RsvlFeej]

I thank you all for you advice. The fuel pump buss is a noice I know well. The hiss was not from it. I figured it could have been a pinched vent tube though. With the tank lifted a bit, and all hoses free, the motor would still not start.
BTW: the battery checked good, is fairly new, and goes on a trickle while stored.

Completely unrelated to dying at low RPMs, but I've fought the wrong problem too many times -

Is your kill switch on? Is your side stand sensor compressed/ gunked up?, got at least a couple gallons of clean gas in the tank?

If not, here's some links and fixes to hard start problems for Gen Is. The answer often is to crank with throttle WFO, but there's some finesse needed.

Whole thread (it's fairly small): https://www.fjrforum.com/forum//index.php?s...ut+down+restart

Post #29 here: https://www.fjrforum.com/forum//index.php?s...start&st=20

or, Post #11 here: https://www.fjrforum.com/forum//index.php?s...ut+down+restart

Post #3 here: https://www.fjrforum.com/forum//index.php?s...estart&st=0

Hope it helps.

 

[JTrider]

Well, I started the topic so I guess I should update what I've found. The bike was set at around 1000 RPM for idle and after many rides/observations I noted whenever the bike would die on quick throttle response (didn't need to actually 'blip' the throttle) there was a corresponding drop of 100 RPM (down to 900 RPM). Whenever this was noted I could roll the throttle on quickly and the engine would die. I first tried premium gas to see if I was getting some odd feedback from the emissions that was causing the RPM drop. On the first tank I had the problem again so I did what several have suggested on the site and that's kick the idle up to around 1100 RPM. I've still noticed the 100 RPM drop and could still 'make' the bike die with a 'blip' of the throttle but as I now have around 600 miles on the bike I don't notice the RPM drop as often if at all.

I wanted to put my observations out there for those having the same problem hopin it would help. Thanks to all who responded with advice. I will be adding the PCIII or doing the Barbarian mod to see if it helps the throttle response and possibly the clutch disassebmly/soak the help with the down-shifting although I might put some more miles on it first. I might also try on alternate oil (some recommended Rotella which is what I run in my KTM).