Fuel cut out on deceleration

[JayBee]

Thanks grog & gsxbarmy.

At the moment, it's chucking it down with rain! But when it stops I'm going to do what kiwicol suggested and see if the motor stays dead if I don't re-open the throttle. The only issue is there may not be a problem. I rode about 300 miles on it the day before I put the question up and it cut out perhaps a dozen times on the over run. So there's a chance it may not cut at all on a short test ride. I think we can put the throttle cable adjustment to bed because I've tried everything from no slack to about 4mm previously. Tick over is now 1100. I will be checking the TPS, STPS and injector sych when I get time. As for the PAIRS, I've no idea at the moment, I had to look it up. You have to appreciate I have had nothing to do with Suzuki's until this week but with all your help I am learning fast. It sounds like disabling PAIRS is a good idea from a running point of view, any downsides apart from emissions? My background is all racing, 35 years of it, probably 90% two stroke and of course we didn't have all the emissions stuff. Neither do my other road bikes, VMax and Ducati because they are 1990's when life was simple! Will report back when I've got some useful info.

[RickC]

A friend's 1400 had similar symptoms to yours, adjusting TPS fixed his problems.

[Hooli]

you can't push start these things like a carb bike. 

Oh yes you can, provided the ignition is on & there is enough electrical power from the battery.

I'd agree with throttle cables, TPS position and balancing the throttles (identical to balancing carbs). Could also be worth checking the vacuum pipes to the MAP sensor (lives between the frame tubes above the throttle bodies). I know from experience that a vacuum leak there can make it cut out like you say, so a split that only happens on the overrun could be possible I guess.

[KiwiCol]

Thanks grog & gsxbarmy.

At the moment, it's chucking it down with rain! But when it stops I'm going to do what kiwicol suggested and see if the motor stays dead if I don't re-open the throttle. The only issue is there may not be a problem. I rode about 300 miles on it the day before I put the question up and it cut out perhaps a dozen times on the over run. So there's a chance it may not cut at all on a short test ride. I think we can put the throttle cable adjustment to bed because I've tried everything from no slack to about 4mm previously. Tick over is now 1100. I will be checking the TPS, STPS and injector sych when I get time. As for the PAIRS, I've no idea at the moment, I had to look it up. You have to appreciate I have had nothing to do with Suzuki's until this week but with all your help I am learning fast. It sounds like disabling PAIRS is a good idea from a running point of view, any downsides apart from emissions? My background is all racing, 35 years of it, probably 90% two stroke and of course we didn't have all the emissions stuff. Neither do my other road bikes, VMax and Ducati because they are 1990's when life was simple! Will report back when I've got some useful info.

Pulling the PAIRS out, or blocking it off does no harm whatsoever. You'll notice it doesn't pop & bang on the overrun any more though.  Some guys like that & so leave them in and working, others like me take it out.

[gsxbarmy]

Taking the PAIRS out also makes it run smoother 

[grog]

PAIRS off sure does make smoother. JAY BEE, to try just block off hose from air box, that stops it working. you can leave it like that or remove the whole thing, fit plates etc. mine is just blocked off with marble. never a prob. make sure you trace hose to get correct one. i know someone who blocked off engine breather first attempt. wow, should see how much smoke can come from a 14 motor. i pulled up at lights, smoke city. guess ive just dobbed on who it was. cant always be perfect, mrs would say, can you ever be perfect. im thinking PAIRS off and throttle cables will solve your problem. do all the tps, synchro butterflies, idle 1100, youll make a honda feel like a tractor. i like the fact that 1100 is idle speed and tps value at closed, easy to remember. hope it works for you. they are amazing bikes when sorted.

[Andre]

Yep runs pretty smooth when all the adjustments are right. Reminds me to block them PAIRS again as I had them unblocked for emission testing (part of our MOT).

But first I have to sort the mess I created when drilling a hole in a wall. PERFECTLY drilled through 2 wire strands  One of them the door communication thingy. My landlord is very displeased with me. He should be happy to get some "exercise"  though

Oh yes, I do have a metal detector. I felt lucky and left it in the closet

[JayBee]

Sorry for the delay, it's been pouring down for two days. I wanted to take the bike out untouched from when I had the problem last week so I could answer KiwiCol's question, ie does it actually stop or continue to tick over if you pull the clutch in? Well I went out today, did 47miles and got the worst possible result. It never missed a beat! Didn't cut out once despite decelerating for England around the lanes. I tried everything, rapid downshifts, slow downshifts, rolling at low rpm. Nothing.

So I guess this one is on hold until it happens again. However I've learnt a lot thanks to your help. I will check the Sync, TPS, STPS etc purely out of interest. The PAIRS is in place (the bike's bog standard) and I might remove it because it does burble a lot on the Yoshi Dual exhaust. I really like the bike and one day it might replace my VMax, but for that I would prefer to put it on carbs (CV's not keihin FCR) and a dyna or other ignition (any threads on that, anyone done it?). I know that sounds madness to many but I do big rides, say 3000miles, often high in the Alps or whatever and I like things as simple as they can be because I can usually fix them easy enough, not that I've had to. The idea of some sensor failure shutting me down in the middle of nowhere or an immobiliser kicking in for no reason does not appeal one bit - learnt that with a Ducati Hypermotard! Thanks for all your help, obviously a great forum with a lot of great 'how to' postings.

[Hooli]

I've only ever had one sensor fail on my 14 & that was a TPS. Still ran, was just lumpy at low throttle. That's in 117k (almost) I wouldn't worry about it letting you down & as the FI adjusts for air pressure it doesn't run lean up the Alps like carbs would.

[JayBee]

Thanks Hoolie, that's a useful reliability indicator worth knowing. Still, just about every breakdown I come across in the Alps etc is either electronics, sensor failure or, believe it or not, wheel bearings (they only seem to change them when they fail). I once met a guy who's four month old BMW went nuts on the electrical side. Made lots of call & got nowhere, waited ages for breakdown then had to go almost 100miles to get on a modem link. 5 min to reset the whole thing. What a caper. By the way, never had any problems with carbs whatever the weather and up to 9000ft many, many times, which is as high as you can go, so tend not to worry about that! Happy touring.

[Hooli]

I believe BMWs went mental after CANBUS was fitted to them, 14s aren't that advanced so it's not a problem to us. I suspect the aftermarket kit needed to make a spark etc if you convert a 14 to carbs would be less reliable than the original FI system, as it's bound to have been tested less etc etc
As for wheel bearings, yeah I knew a six week old ZZR1400 that's rear wheel bearings went in the Alps. Mine are still original with no play etc....

[Andre]

The sprocket carrier bearing is known to be a bitch though.  Read plenty of stories about it. Mine appeared to be fine - until I took it out (44k km). The only thing that lubricated it was the rust Replaced with a dual side sealed one.

[Hooli]

Aye I replace those with every chain & sprockets, they are always rough & rattly by then.

[Hooli]

Thanks Hoolie, that's a useful reliability indicator worth knowing.

Just thought of another one, the throttle cable snapped around 110k. Would have suffered that with carbs too.

[JayBee]

Hi All, Ref my problem on deceleration it's now cured. I know how I cured it, no idea why though. Might be of help to someone so here goes. Recap: On deceleration the bike would sometimes suddenly behave as if the motor had cut giving a big increase in engine braking, enough to make the tyre protest if you were on corner entry. It didn't do it all the time (about 20% I guess) and as soon as you opened the throttle it was away again. I had done about 300miles that day, posted the problem and got lots of helpful replies, thank you. KiwiCol asked if the motor actually cut. I can tell you now it didn't. If you left the throttle closed the bike would slow dramatically, almost like you knocked it down a couple of gears too early, but declutch at the last moment and it ticks over fine. Anyway, after the days of rain stopped I did about 40 miles and it never did it once. Ran perfect. I checked pretty much everything suggested and all seemed fine. Well I did another 300 mile trip a few days ago. Went to the coast, 135miles and it ran absolutely perfect. Stopped at the cafe for an hour (so cooled down but not cold) and after about 10miles it started doing it again and pretty regularly. Big engine braking followed by instant go if you just touched the throttle. That carried on for about 50miles when I hit a big traffic jam. Pottering along on tickover I had to keep pulling the clutch in (too fast in first for the traffic) and noticed the tickover had gone up from around 1100/1200 to 1500/1600. No idea why. Anyway I lowered the tickover at the side of the road right down to sub 1000, about 900 maybe. And as if by magic, the problem on deceleration has vanished at the same time. I did over 100miles from there that day and it was prefect. No idea why. I've probably done another 100 since, still perfect. So if you get this issue it's worth trying a low tickover. Any suggestions why?