Newbie, Engine Stutter /missing when trying to hold steady 2k

[willieE]

Afternoon Folks, Just got a 1400 my first injector bike but it seems to be running roughly coughs and bangs.
Things I have done:
No fault codes C00
TPS  checked and set,
Injectors balanced ,
Thought it might be CPS REPLACED no improvement.
Plugs changed.
Teabaged,
If I remove any of the sensor plugs ECU goes to safe mode and runs better but not perfect.
This makes me think plug,coils, injectors, are good?
Any ideas?

[seth]

I'd be checking the connectors in the loom especially the big white one on the left side of the airbox behind the side panel.
good luck 

[BlackAdder]

Set idle to 1100rpm and sync throttlebodies. And check that the intake airpressure hose (and hoses between throttlebodies) aint leaking and that they are connected.

CPS? You mean the throttle psition sensor right? Have you measured the values? ~800 ohm closed and high 3Kohms open

[willieE]

Thanks for the replys , Intake pressure hoses are attached and no leaks, (sprayed easystart around injectors and rubbers, no increase in revs) CPS cam position sensor, as read a post on here that gave same indicators as i have. I will retest the TPS but it seemed OK. Really is getting personal this injector stuff  (can i just fit mikunis? )

[Hooli]

If you've listed what you've done in order then the TPS will need redoing. Syncing the throttle bodies needs to be done before the TPS & SPS are adjusted.

As already suggested, fill the white multiplug under the LH side cover with contact cleaner, do the same for the kill switch, clutch switch & sidestand switch.

[Proteous]

What year bike do you have?
I ask because it would appear that the STVA sensors seem to be a common fault on K2 and K3's now... I think they seem to be reaching the end of their life. I had never heard of one going before then the last 12 months i know of about 5, all the same age.

If it is the STVA then prepare for a 120 quid bill for the sensor and a two week wait as their are none available in the UK.. Well there wasnt when i needed one.

[ARH]

Did you check the free play on the throttle cables?  If that is out of spec I believe this will also through the tps out of whack as well...

Had similar issue with my K2... would not run smoothly at 2k almost like on and off throttle... cable adjustment fixed it.

[grog]

coughfs n bangs, not missing. seems like a fuel starvation prob. check the fuel pressure. high pressure filter blocked? could be. how noisy is pump? noisy is a sure sign its working hard, high press. filter blocked. if it is, dont replace just do by pass, fit external filter. one of the best mods.

[Blubber]

We recently had a member with a faulty intake air pressure or manifold air pressure sensor which threw no alarm code.

When he disconnected the pressure sensor hiding under the seat behind the RHS cover the bike ran fine. ( albeit with an error due to that disconnection )
After replacing the pressure sensor under the tank it was solved.

His problem was slightly different but might help diagnosing the error.

http://gsx1400owners.org/forum_test/index.php?topic=1443.0

[willieE]

Thanks for all the input retested the TPS  closed is spot on but open is only just above half 1.3k, could this be my problem? Is it right the GSXR600 K1-3 have the same TPS?

[Hooli]

Yeah that could well be it.

A low revs/throttle the bike uses manifold pressure to determine how much fuel to inject. As the revs rise or you open the throttle more it changes over to just assuming how much is needed from the TPS & revs. So a TPS that under reads like that would make it get rather lean.

[grog]

Think youve found your problem, well done

[willieE]

Thanks for all the responses I am now on the hunt for a TPS if anyone has one? Dont want to buy a new one to find out it isn't the problem 

[willieE]

We here I am back again , Checked the TPS and gave it a clean now operates smoothly and in a linear resistance all the way up to 4.3k,(off bike) set it as per the book, thought that's was it  :rofl2:nope still pops and stutters. Did some more checks found the popping is from cylinder 1. Disconnected the plug cap no popping Plug cap was breaking down on sidewall, that will be it I thought.  Changed the cap out still popping changed plug again nope. Getting a bit frustrated with this, could it be the injector? 
Any clues or tests? Not done a compression test yet or valve gap, would valve gap give this symptom?

[seth]

might be worth checking the injectors
try changing 1 and 4 as there easiest to get at and see if the problem moves cylinder
there is a filter in each injector .
i had a simular problem and thats what it turned out to be .
http://www.injectortune.co.uk/index.html

sorted mine £57 for all 4 with a report