Acceeration hesitation under heavy acceleration

[Windy]

Hello,
I have recently had an issue with my GSX hesitating when accelerating.
I tried new plugs and have removed the injector bodies.
The bike was fine before I put it away for the winter but then it started this issue.
For those that have had problems like this before it turned out to be the tea bag filter or low pressure filter at the bottom of the fuel pump inside the tank. Suzuki call it the fuel pump strainer. It was full of rusting horrible bits
This is an easy DIY job so have a go ensuring the tank is nearly empty as you dont want to ruin your paint work. the High Pressure filter (the big black bit also comes apart and I managed to find a utube guide to assist as well. Use carb cleaner to flush out this filter.
An original t bag filter is around £65.00 so it is worth having a look before you buy one as you can clean the old one with carb cleaner to get rid of most of the debris. Make sure you clean out the bowl it sits in as well.
Hope this helps. 

[gsxbarmy]

Well done - but had you looked here....
http://gsx1400owners.org/forum_test/index.php?topic=430.0

You might also run a couple of tankful of BP Ultimate or similar through as well to clean up any residue in the system. I found running it in my 14 all the time significantly reduced the clogging and muck around the filter and throughout the rest of the fuel system

[David Nolan]

Had the very same issue cleaned the bowl where the pump sits and cleaned the tea bag.. Problem solved

[grog]

a better thing to do is by pass the high pressure filter. fit external one. on here somewhere. no more problems, just clean out external every now and then. tea bag pick up filters are fairly universal. easy for me as in car repair business. i just grab a good one when we change car pumps. ill try and find a suitable one and post what it is.

[seth]

http://gsx1400owners.org/forum_test/index.php?topic=87.0
there are links here for tea-bag filters 5 for £7

[Michael Whitney]

Just wondering what the exact problem was with your GSX? I've just brought a gsx1400 k5 model with 6785 miles on the clock. Got insured for it Saturday and took it out and noticed sometimes I'd open it up and it'll stutter I guess is the best way to describe it as if It's not getting fuel for a second then starts pulling like a train. Didn't know if it was because it's been converted to a 4 into 2 exhaust system and maybe needs a remap or if it's likely to be the tea bag filter?

I did read your other post saying it in fact turned out to be the ignition coil breaking down but not sure if a bike with such little mileage would have a problem like the coils breaking down?

[gsxbarmy]

The 4 into 2 conversion will have had no impact at all on fuelling Michael.

Given the low mileage of your bike, its possible that its lack of use rather than anything else! What I would suggest is running a 2-3 tankfuls of Shell Optimax or BP Ultimate through to give the injection system a bit of a clean out. You could use injector cleaner, but in my experience, using the better grade fuels works better as they have better detergents in which should clear the issue. If however she still does it after that, then there's a possibility that you may need to clean out the fuel pump/filter, but at present I doubt it.

The other aspect you could check is for any slack in your throttle cables, it tells you how to adjust these in the handbook. Sometimes if they are a little loose, cracking the throttle open injects a tad more juice than normal and causes a slight stutter whilst the system catches up and clears the excess fuel

[Hooli]

Could be a dirty clutch switch too, mine is always a twat when that plays up. I just fill it with switch cleaner/WD40 (depends whats to hand) & carry on. The switch never needs replacing.

[Michael Whitney]

The other aspect you could check is for any slack in your throttle cables, it tells you how to adjust these in the handbook. Sometimes if they are a little loose, cracking the throttle open injects a tad more juice than normal and causes a slight stutter whilst the system catches up and clears the excess fuel

Could be the cables then, throttle does have a fair bit of play in it if that's what you mean by loose cables?

[gsxbarmy]

The other aspect you could check is for any slack in your throttle cables, it tells you how to adjust these in the handbook. Sometimes if they are a little loose, cracking the throttle open injects a tad more juice than normal and causes a slight stutter whilst the system catches up and clears the excess fuel

Could be the cables then, throttle does have a fair bit of play in it if that's what you mean by loose cables?

Exactly what I mean Michael 

[Michael Whitney]

Probable a stupid question but why does that cause it to stutter? Been on a carb'd bandit 600 for 3 years lol, throttle play would just mean having to twist throttle further before it started accelerating.

[seth]

makes the difference because its not carbs its fuel injection and needs everything to be correctly adjusted to give a smooth operation and run properly.

[Blubber]

Probable a stupid question but why does that cause it to stutter? Been on a carb'd bandit 600 for 3 years lol, throttle play would just mean having to twist throttle further before it started accelerating.

The 14 is fuel injected,  like mentioned in the post above.  It injects fuel based on the throttle position but still uses butterfly valves in the throttle bodies to regulate the air.

The afr ( air fuel ratio) has a optimal range.

On the left side of your throttle bodies is the tps. Throttle position sensor. On the right side is de stps.. Secondary throttle position sensor.  These 2 sensors need to be set correctly vs the actual valve positions...the tps being the most important one.

Especially in the low rev range,  a small difference in the tps can cause a huge on / off effect.

See it as injecting fuel based on a 10% open valve whilst it only 5% open.... It will be over fueling.

The slack in the throttle cables can cause problems because it allows the butterfly valves to move due to the suction of the running engine. This movement is transferred to the tps and the ecu will inject based on the movement....Whilst you think you are keeping the throttle steady.

[KiwiCol]

Very good description Richard.

[grog]

excellent description, very good if not brilliant.