Hoping someone can help. My bike has a habit of stuttering sometimes when going round a corner in 2nd and opening the throttle it stutters. Also sometimes when I go for an overtake I open the throttle and it is like the bike thinks about it and then all of a sudden it will accelerate fine. Sorry for the description but it is the best way I can think of explaining the symptoms.
So far I have replaced the vacuum pipes for new silicone pipes. The PAIRS system was blocked off by the previous owner. I have also removed the fuel pump and cleaned out the tea bag filter, pressure relief valve and high pressure filter. I have also adjusted the TPS and STPS.
Can anyone think of anything else it could be. Is it possible that the throttle bodies need to be calibrated and 8f so is there anyone local to York that has a carbtune or similar that wouldn't mind helping me synchronise them?
Sounds like injectors may need a clean too. Failing that, you may need to check if the pressure regulator is still working, need to check the flow rate from the pump. The manual specifies what it should be
If you were closer I'd be happy to lend you my carbtune and give you a hand.
paul, very hard to diagnose online. Plugs new?Leads get dirty fittings into plug caps, trim n refit.Would give more of a misfire not total lag. Injectors sounds prob to me but telling you to spend quite a few bucks to have cleaned, then doesnt help, not what i want to do.
Check the recommend suppliers section there's a company called injectorclean (based in the uk) do a great service and service your injectors almost by return of post
Costs about £55 .
Then have the throttle bodies synchronised.
All I can think of .
Good luck
EDIT: Link to company mentioned: https://gsx1400owners.org/forum/index.php?topic=95.0
Thanks everyone a few things to try there will set some time aside soon to check the flow rate of the pump, plugs and leads and all else fails I will have to send the injectors off to be cleaned. The bike has only done 13,000 miles but I suppose it has been sat for a few years although I have not done 1500 since beginning of March this year.
Mate, i remember another bloke having all sorts of probs. Did everything, injector service fixed it. If he reads this he'll tell his story.
Quote from: grog on Saturday, 14 May 2022, 05:41 PM
Mate, i remember another bloke having all sorts of probs. Did everything, injector service fixed it. If he reads this he'll tell his story.
Thank you
Hey Paul.
I had similar problems. I tried everything that you have done and I sent my injectors to Injectortune who cleaned them. He does a before and after test and you can see the improvements. Also he sends new seal etc to fit. They were back within 5 days! Fantastic service and not ridiculously expensive for what you get.
Also, crazy suggestion, but it has just fixed my bike. Very recently. It has been a bit reluctant to start , and hesitation and "stumbling." Completely flummoxed me, but the problem with the starting turned out to be a poor engine to frame earth lead that had corroded out to only a few strands. At the same time I changed the tea bag filter and the plugs (which were due anyway) and she is now running beautifully.
Good luck. Chip.
Aye these bikes are old enough the earths are getting dodgy, don't forget the little one under the RH side cover. It's got a pointless spade terminal in the lead that goes manky.
Also clutch switch, yours isn't bypassed or sticky is it? When the clutch switch is engaged it causes a different fueling/ignition map to be used for better starting. I know when I bypassed mine years ago the bike would back fire and cough every time I wound the power on, as well as drinking like a fish.
Good point about earths Hooli.
Both that spade terminal & the main engine earth on top of the gearbox were corroded on mine & added to the running issues I had.
Remember, as I'm sure grog knows, these bikes aren't that advanced. The sensors all work on voltages put out & a dodgy earth will upset the readings from all the sensors back to the ECU.
Quote from: Hooli on Monday, 16 May 2022, 08:32 PM
Both that spade terminal & the main engine earth on top of the gearbox were corroded on mine & added to the running issues I had.
Remember, as I'm sure grog knows, these bikes aren't that advanced. The sensors all work on voltages put out & a dodgy earth will upset the readings from all the sensors back to the ECU.
That must be why the news is full of ideas to save the earth !! :rofl2:
Just try calibrating the TPS as well as a throttle body balance, you never know :onya:
Try and notice how much throttle you've got on when it happens too. In my experience the TPS fails over a small amount of it's total sweep, so you can cause an issue turning to that much throttle. Both times I've had a TPS fail it's been about 1/4" of throttle off idle, but when tested with a multimeter it passed the test in the manual.
Thank you to everyone for your suggestions I will have a look at the earths this weekend I have some annual leave coming up at the beginning of August where I won't be using the bike (family holiday :angry:) so would be an ideal time to look at sending the injectors off to be cleaned