Engine hesitation/miss

[mjdoliveira]

Hello everyone,

 

I have a 2000 Sport. Under light throttle the engine will tend to miss but never actually stop running. Once you open it up the miss goes away, for instance it accelerates hard without any problem. I see some problems mentioned about the electric petcock, but I would imagine that the problem would then exist under all throttle conditions. Dirty fuel injectors?

 

No issue with tank suck as I've removed all of the plumbing associated with the vapor recapture system.

 

Thanks for your help!

[raz]

Sounds like the 'italian sneeze' that many of us have experienced. Check valve lash. A tad wide is better than too narrow. Then check throttle body sync. If problem remains, check TPS. Here too, it's better to have it read a little high than low, within reason.

 

My particular bike ran awful if I used factory spec 0.10/0.15 mm for valves. Opening it to 0.15/0.20 or even 0.20/0.25 made all problems vanish, rock steady idle and no misses at low load cruising. Maybe this is no longer true after heads overhaul, we'll see.

[gstallons]

Do you have a PowerCommander installed and or what is the TPS setting?

[jimbemotumbo]

My 2000 Sport behaved the exact same way. As stated, it is a tuning issue.

 

Adjust the valves to world spec, not US spec. Then set your TPS per instructions presented in the sticky so named.

The key is to ensure ALL your linkages are disconnected from the TBs in order to get accurate adjustments.

Finish off with a good balancing of the TBs, but not at idle. Balance them so they are most evenly matched at 1500 and 3000 rpm.

 

- Jim

[mjdoliveira]

Do you have a PowerCommander installed and or what is the TPS setting?

 

Used to have a Power Commander but removed it because of eerily similar problems assuming it was a short in the PC, though at that time the problem went away. Unfortunately have no understanding of the TPS and what is required -- something I will need to bone up on.

[mjdoliveira]

Gentlemen,

 

Thank you for all of your input -- will do as recommended and let you know the results.

[gstallons]

Used to have a Power Commander but removed it because of eerily similar problems assuming it was a short in the PC, though at that time the problem went away. Unfortunately have no understanding of the TPS and what is required -- something I will need to bone up on.

 

Study this diagram; N5 is ground, K8 is 5v supply, K7 is v reference. At idle the K7 v ref is about .450v or 450 millivolts, as throttle angle is increased K7 travels toward K8 increasing signal return voltage to the ecu telling it throttle angle is greater. at WOT v ref is or about 5v. Since throttle angle is at cruising speed 75% of the time the greatest wear will be on that point, wearing it out and causing a glitch at that point.

 

http://z.about.com/d/autorepair/1/0/R/3/42231354.gif

[Kiwi_Roy]

My V11 has similar symptoms, just misses a beat now and then at idle or under moderate steady power, it misses about 1 in 1000. It seems to me like the ignition is missing or perhaps the injectors not opening.

I have only just set the TPS and balanced the throttles.

The Italian Sneeze is an apt description.

Roy