GPZ 1100 A1 Throttle body replacement

I seem to have an issue with the DFI on my GPZ 1100 A1.
Symptoms are spluttering and poor throttle response  around 2-3500 RPM, once above that and at WOT no problems.
I have taken the throttle bodies out, cleaned everything, tested/cleaned the injectors, Cleaned and benchtested the TPS, replaced all fuel/vac Hoses, checked the NRV, replaced fuelfilter, cleaned the tank/ fuel tap.
Once assembled it acts as if it has an airleak, with revs hanging up around 2 k before settling down low at maybe 700 rpm, I have checked and there is no airleak, thinking maybe TPS sensor acting up or maybe the axle to TPS has to mych play in it? Will do some more troubleshooting, later this week, any input is welcome, I have searched the forum and tried all the tips regarding the DFI.

Anyway... Has anybody on here succesfully installed any other throttle bodies and another ECU?  
Was thinking about swapping in a set of RS34:s but where is the fun in that?  A Modern system seems more tuneable than carbs as well.
 

If its not an air leak. It sounds like the TPS needs adjusting. Mine was the same until i adjusted it by ear. Was hunting and jerking between 2,500 and 3,000 rpm Runs brilliant now.
there’s a procedure to do it you’ll find on google. The turbo is a similar procedure.

Here’s what i followed

""First off, many Kawasaki Turbos came from the factory too lean-burning to even idle properly. Another symptom of a lean burn is a noticeable stumble off-idle. Fortunately you don't have to live with a "bucking bronco" Turbo.

The cure is rather simple. Backout the four tiny screws that secure the Throttle Position Sensor (TPS) cover (unscrew each a little at a time - they're designed to stay in the cover). The TPS is attached to the right side of the fuel injector throttle bodies and the cover has the silver "DFI" insignia. Notice that the TPS is held in place with two adjusting screws with a globe of yellow paint on each head.

With the engine fully warmed loosen the two adjusting screws just enough so the TPS can be rotated. Now simply turn the TPS (turning to the right richens the mixture - to the left leans it out) in VERY small increments (it's an extremely sensitive sensor) until you find the spot where the engine idles best. Turning the TPS to the right also raises RPM so you'll have to lower it by turning the throttle adjustment knob on the left side of the throttle bodies. Keep rpm at about 1,000 to 1,500 during this adjustment. When you've found the "sweet spot," tighten the adjusting screws, reinstall the cover and take a road test. Chances are that's all you'll need to do to cure the low-speed bucking.""


its quite marked how big the differences can be with just a small movement of the TPS.

Mine went from running rough sub 3,000, to running fine throughout the lower revs but taking longer to warm up - which is how i chose to leave it. 

in both cases it ran fine from 3,000 upwards.

Is there a way to check the fuel delivery pressure and volume? Hanging idle is  usually associated with a lean mixture.
Since you have confirmed no air leaks, it is possible that  lower than spec. fuel delivery volume can be the issue... Pumps do wear out...
At partial throttle opening, slightly lower than nominal fuel flow will have a more pronounced (and apparent)  detrimental effect on air/fuel mixture than at wide open throttle. 

H.

Sometimes the fuel tank check valve is clogged/stuck or the o-ring is no longer present or sealing!

 

kzrider.com/forum/2-engine/615786-fuel-t...ket-sealant?start=12

Hi guys and sorry for the very late reply.
The problem is almost sorted!
I forgot to see the synch of the throttle bodies and the adjustment of the TPS as a whole system, if I change the adjustment of the butterfly valves  it may cause the bike to be either lean or rich depending on wich way I adjust, so here is what I did:
I adjusted a bit on the throttle bodies to come closer to synch (it was way out), adjusted the TPS and the idle screw for a steady idle at around 1500 RPM, once I got it synched i did some fine tuning of the TPS, put a screwdriver down my boot and went for a ride, adjusted some moore until I found a sweet spot, still a bit rough down low and the weather is not fit for riding atm, love how smooth it is now especially when riding the twisties....
Scoored a zx-9 rolling chassie the other day, plan is to take at least the forks wheels and brakes for the GPZ1100, maybe rear suspension as well...

Sounds like i rape a ZX-9R donor bike for parts.