I have a misfire which is alluding my limited diagnostic abilities. The bike has developed a stutter/misfire when under load if the throttle is opened quickly. The engine revs fine when in neutral (no load). I experienced a similar issue a year or so ago and it was fixed through a coil replacement. So that was my first go to. I've tested both coils and the resistance readings (primary and secondary) are the same for both coils (3ohms and 12,000ohms from memory). I've replaced the spark plugs and checked for healthy spark.
I'm leaning towards a Throttle position sensor, given that I can still accelerate smoothly provided I open the throttle gently and was going to follow other advice I found here on testing that. A quick search suggests than finding a replacement (if it is the TPS) will be difficult.
Any guidance appreciated.
Yes, sounds like TPS or STP issue. Check online at mickhone.com.au theyre not cheap AUD 165 each, but if never been replaced, cost effective for the life of the bike.
Make sure you set them up right (correct Ohm and voltage readings at FC and FO) and balance the throttle bodies as well.
I've actually got a TPS here somewhere, I replaced mine when I didn't need to, so I have a spare if ya need one.
You could try my one & see if it fixes anything if ya like. Where abouts are you situated?
Quote from: Eric GSX1400K3 on Monday, 08 January 2024, 10:14 AMYes, sounds like TPS or STP issue. Check online at mickhone.com.au theyre not cheap AUD 165 each, but if never been replaced, cost effective for the life of the bike.
Make sure you set them up right (correct Ohm and voltage readings at FC and FO) and balance the throttle bodies as well.
Thanks for that... and the link. Really appreciate the quick reply.
Thanks kiwicol. That would be a huge help, happy to pay whatever you think is fair. I was riding home tonight thinking it had cleared itself... so opened her up a bit.... Within the speed limit of course! But no she still stuttered. Will I be in danger of doing any damage? I'm in Papamoa, Tauranga.
I'd be thinking high pressure fuel filter before I looked at the TPS as it sounds related to the need for high fuel flow rather than throttle position.
Every time I've had a TPS issue, I've been able to reproduce it by moving to a particular amount of throttle. Plus it's always happened at low throttle where the TPS gets the most wear.
Quote from: Hooli on Monday, 08 January 2024, 06:38 PMI'd be thinking high pressure fuel filter before I looked at the TPS as it sounds related to the need for high fuel flow rather than throttle position.
Every time I've had a TPS issue, I've been able to reproduce it by moving to a particular amount of throttle. Plus it's always happened at low throttle where the TPS gets the most wear.
Thanks. I can reproduce the misfire/stutter at low throttle or anywhere in the rev range provided I'm heavy with the application but as I've never looked into the state of the filter it's certainly an area to investigate.
Quote from: nzk2gsx on Monday, 08 January 2024, 07:00 PMQuote from: Hooli on Monday, 08 January 2024, 06:38 PMI'd be thinking high pressure fuel filter before I looked at the TPS as it sounds related to the need for high fuel flow rather than throttle position.
Every time I've had a TPS issue, I've been able to reproduce it by moving to a particular amount of throttle. Plus it's always happened at low throttle where the TPS gets the most wear.
Thanks. I can reproduce the misfire/stutter at low throttle or anywhere in the rev range provided I'm heavy with the application but as I've never looked into the state of the filter it's certainly an area to investigate.
I think you're misreading what I mean, or I didn't explain it well.
I could reproduce a TPS error by opening the throttle to exactly the the same position each time. Didn't matter what speed the engine was revving at, the same amount of throttle would cause a splutter on the overrun the same as it would when accelerating.
I seem to get about 50k miles per high pressure filter & as they block it starts off like the issue you have & gradually gets worse till it limits the speed of the bike. It's worth checking the teabag (low pressure pickup filter) on the pump too as they are easy to wash out. Some people prefer to bypass the high pressure filter, I know the Ozzys do it a lot so there's bound to be info on what to use somewhere on here. Others have back flushed the high pressure filter, which seems to work if it's not too blocked when you try it.
There was recently chinese copies of 'busa high pressure filters on ebay, much much cheaper than anything for a 14. They fit fine, the only difference is the 'busa ones have two threaded blind holes in the top for their fuel gauge that 14s don't need. This looks the same as the one I got as a spare (because they are about £170 from Suzuki) https://www.ebay.co.uk/itm/126040100649?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=qukuregvriu&sssrc=2047675&ssuid=PsBv5obTS2S&widget_ver=artemis&media=COPY
I think Hooli is accurate in his diagnosis of the fuel filter, especially if it's never been cleaned / checked.
Here's the link to the HP filter mod. https://gsx1400owners.org/forum/index.php?topic=590.0
I'm happy to get the TPS sensor out, but reckon you'd find no difference.
All good - I'll dive into the fuel filter as that is the collective advice and least cost option (provided I don't break anything) and report back. Thanks all.
I forgot to mention that periodically I get the F1 error light popping up when I turn the ignition - its done this for years and simply off and on again has been my go-to solution. Does that effect the advice?
Quote from: nzk2gsx on Tuesday, 09 January 2024, 05:44 AMI forgot to mention that periodically I get the F1 error light popping up when I turn the ignition - its done this for years and simply off and on again has been my go-to solution. Does that effect the advice?
To be honest I thought the FI light came on as part of the self check process when the ignition was turned on with the stop switch in the run position prior to starting the engine, I'm sure mine does momentarily :confused1:
OK - so I've had the fuel filter out as per the guide, cleaned everything. The tea bag was pretty dirty but the high pressure filter was in good shape. Cleaned the injectors whilst I was there. Road test - no joy unfortunately, the issue remains. :frustrated:
Quote from: nzk2gsx on Tuesday, 09 January 2024, 11:38 AMOK - so I've had the fuel filter out as per the guide, cleaned everything. The tea bag was pretty dirty but the high pressure filter was in good shape. Cleaned the injectors whilst I was there. Road test - no joy unfortunately, the issue remains. :frustrated:
so no black stuff out of the hp filter when you back flushed?
Clean as a whistle. But there's good news. Many months back I was having issues with the clutch switch, my local garage rigged it to work and I thought nothing more of it although I got a replacement which I never fitted. I was scouring the forum and saw that the clutch switch initiates a different map. On replacing the switch and subsequent test ride I can confirm this was the issue. With the clean fuel filter, new plugs and proper map this thing now flies.
Perhaps do a flow test and a pressure test, that'd confirm it one way or the other. If you've had the HP filter off I hope you used some wire to secure it back in place, (https://gsx1400owners.org/forum/index.php?topic=1610.0) the plastic clip has a tendency to break once it's been undone.
@Andre mate, do you recall what the flow rate and pressure should be? (reckon you'll remember off the top of your head) :onya: :clapping:
Yes, I followed the write up. But she's all good now, so happy news. The sad end to the story is that my GSX will now be up for sale. I planned to keep it forever but after knackering my knee it's just not getting used.
Quote from: KiwiCol on Tuesday, 09 January 2024, 02:48 PM@Andre (https://gsx1400owners.org/forum/index.php?action=profile;u=736) mate, do you recall what the flow rate and pressure should be?
43 psi
1200 ml/30 sec
That's the minimum for passing, Mine has 1440 ml and 45 psi
So nzk, it all healed itself, and you dont even ride as knee is buggered. Makes no sense to me asking for help. IMO only.
That's very unfortunate mate maybe a three wheeler 😳
Quote from: grog on Tuesday, 09 January 2024, 06:10 PMSo nzk, it all healed itself, and you dont even ride as knee is buggered. Makes no sense to me asking for help. IMO only.
It didn't quite heal itself.. the issue was the clutch switch, but probably made worse by a dirty filter. I've loved the bike over the past 7 years and don't want someone else to inherit any issues.
[quote :grin: author=GSXKING link=msg=104183 date=1704789487]
That's very unfortunate mate maybe a three wheeler 😳
[/quote]
Cheers... hmmm I can't see myself on one of those.... Perhaps a cruiser .. feet forward so more comfortable but a permanent dark visor to hide behind :cool:
Nice fix, I'd forgot to suggest that.
I had similar with mine years ago when I bypassed a faulty switch till the new one arrived.