Ignoring the doom questions above I'd guess at a fuel issue
Usual numpty-level question:
On the way back from a 30 mile run out, I went to overtake and pressed the accelerator and the normally smooth power delivery was staccato and lumpy.
(6,500rpm). Got to 7,000 rpm and the rough running continued, so eased off. All fine at 6k rpm, but when I tried dropping a gear and gunning it, I got
the same problem.
Engine has done 780 miles from new. Gen2 1340cc.
Where do I start looking please?
Oil pressure and temperature are normal and engine appears to idle smoothly.
fuel starvation at higher revs?
Check lines and filters perhaps.
Coil and plug leads?
Had this on my R1 engine just before winter hibernation, was fine at low revs but the extra vibrations at high revs was slightly dislodging a plug
lead causing it to run rough. Quick nip with the pliers sorted it.
Not sure if the busa is similar or if its coil on plug?
I had similar problems at 2-3k rpm at WOT with my M3 engine - turned out to be VANOS (variable valve timing) failure, easily fixed in my case with a couple of new O-rings. No idea if your engine has variable valve timing though? Probably not common on bike engines?
quote:
Originally posted by nick205
fuel starvation at higher revs?
Check lines and filters perhaps.
quote:
Originally posted by Nickp
quote:
Originally posted by nick205
fuel starvation at higher revs?
Check lines and filters perhaps.
+1 first place to look for me too including pump.
quote:
Originally posted by bobinspain
Usual numpty-level question:
On the way back from a 30 mile run out, I went to overtake and pressed the accelerator and the normally smooth power delivery was staccato and lumpy. (6,500rpm). Got to 7,000 rpm and the rough running continued, so eased off. All fine at 6k rpm, but when I tried dropping a gear and gunning it, I got the same problem.
Engine has done 780 miles from new. Gen2 1340cc.
Where do I start looking please?
Oil pressure and temperature are normal and engine appears to idle smoothly.
Are you sure the engines done 780miles from new? was it in a damaged bike that ran when on its side?
Ignoring the doom questions above I'd guess at a fuel issue
Any warning codes? Crank sensor problems can cause your symptoms, but would normally throw a warning code.
quote:
Originally posted by matt_gsxr
Any warning codes? Crank sensor problems can cause your symptoms, but would normally throw a warning code.
I had similar issues in my daughters car (not bike engined) where motor would start run drive ok but hesitate etc under load.
Checked fuel pressure, replaced injectors, distributor cap, plug leads (as all were looking fairly tired) no luck.
Turned out spark plugs were breaking down under load - new set of plugs - all fixed.
David
[Edited on 6/12/12 by feckn7]
quote:
Originally posted by feckn7
I had similar issues in my daughters car (not bike engined) where motor would start run drive ok but hesitate etc under load.
Checked fuel pressure, replaced injectors, distributor cap, plug leads (as all were looking fairly tired) no luck.
Turned out spark plugs were breaking down under load - new set of plugs - all fixed.
David
[Edited on 6/12/12 by feckn7]
Hi Bob
the bike running on its side after accident shouldnt figure as the bank angle sensor will cut them dead when leant at an angle with no cornering force
to centralise the pedulum, so I dont think thats it. As others have said I would check fuel pressure first - does it employ an external fuel pressure
regulator if so can you plumb in a pressure guage to check the line pressure. Also when ignition is on are you getting any unusual noises from the
pump.
Most faults with the ignition/fuel system will manifest themselves with a fault code so I would definately check the fuelling first - oh and check the
main engine earth hasnt come loose.
Feel frre to call me if the problem persists
Best regards
Andy
Had a similar problem on my hayabusa engine and changed the fuel pump and that solved it. Good luck.
quote:
Originally posted by Andy B
Hi Bob
the bike running on its side after accident shouldnt figure as the bank angle sensor will cut them dead when leant at an angle with no cornering force to centralise the pedulum, so I dont think thats it. As others have said I would check fuel pressure first - does it employ an external fuel pressure regulator if so can you plumb in a pressure guage to check the line pressure. Also when ignition is on are you getting any unusual noises from the pump.
Most faults with the ignition/fuel system will manifest themselves with a fault code so I would definately check the fuelling first - oh and check the main engine earth hasnt come loose.
Feel frre to call me if the problem persists
Best regards
Andy
Bob
u2u replied to
give me a bell on 01449 736633 if you want to discuss - I might be able to work through a few things remotely with you
regards
Andy
I had a similar issue with my Busa powered Seven a couple of years ago. The high ethanol content in the Sunoco gas that I started to use had dissolved the anti-slosh foam baffles in the fuel tank and it had plugged up the injectors. A cleaning of the injectors and flushing the tank after removing the foam cured the problem and no issues since.
quote:
Originally posted by Andy B
Bob
u2u replied to
give me a bell on 01449 736633 if you want to discuss - I might be able to work through a few things remotely with you
regards
Andy
For those who are interested and particularly for those who kindly offered advice:-
Car battery showed 12.84v at 'rest.'
Momentary drop to 12v on start-up.
Idling, 13.8v
At a steady 4,500 rpm, 14.9v.
When removing the battery cover/holder, it was apparent on the tubular piece with 2 securing-screws that nip the HT lead, the screws were
'hand-tight' only. Additionally, the collar which attaches to one of the battery terminals was far from tight.
All secured, I went out for a quick run. (In the car !!!!)
In 2nd, 3rd and 4th gears, I took it as far as 8k rpm, smooth as you like.
I'll give the car a more thorough shakedown in 5th and 6th manana. (It's 17c here right now, but blowing a hooley).
Thanks troops.
Well done Bob, glad it was a simple fix for you....but a bit worrying I know at the time?
Gout-induced delay (not recommended!) in road testing.
Just been out (19c and sunny).
Smooth as you like in all gears (up to 8k rpm anyway).
Iffy HT connection.
My last posting was somewhat optimistic.
There's good news and bad news. First the bad: Just done a 30-miler and was able to give it a good thrash through all gears on a near empty
autopista. 1st to 4th, wound it up to 9k rpm and all normal. In fifth and 6th, above 7.5/8k rpm it stutters and and loses power, like it's hit a
wall. I progressively floor the throttle in 5th and 6th and it pulls like a train until 'the wall.' If you put your tongue in the roof of
your mouth and make the rrrrrrrrrr sound, that's what the engine feels/sounds like and no increase in power delivery. I naturally lifted off at
that and re-tried------same result.
Any ideas based on the above?
The good news is that it was 'shirt-sleeves' weather at 20c and sunny. As they say, "you can't have everything." (where
would you put it?)
Regards, Bob.
Sounds like miss fire bob I would try taking the plugs out and looking for any difference in colour ect may possibly be a coil pack or a plug breaking
down under load also do you have a power commander fitted? May be worth disconnecting this and trying it as standard to rule it out, if you got no
fault codes it's bound to be something daft like previously said check all earths and battery leads and a good check round all the multi plug
connections
[Edited on 6/1/13 by chicade]
Where in Spain are you bob my parents live in costa del sol and my dads a keen and very able mechanic and virtually built my Mk from scratch converting it from car engine to r1 if your not too far away am sure he would help
quote:
Originally posted by chicade
Where in Spain are you bob my parents live in costa del sol and my dads a keen and very able mechanic and virtually built my Mk from scratch converting it from car engine to r1 if your not too far away am sure he would help
Bob, did you have any luck with this? Mine's literally just started to do it, occassionally exactly as you describe. Battery terminal was slightly loose but that didn't fix it. currently looking at a check of all wiring, fuel lines, and a change of plugs and fuel filter. I am pretty gutted as I'm booked into donington on sunday, so I HAVE to fix it tomorrow, argh!!
quote:
Originally posted by Custardpants
Bob, did you have any luck with this? Mine's literally just started to do it, occassionally exactly as you describe. Battery terminal was slightly loose but that didn't fix it. currently looking at a check of all wiring, fuel lines, and a change of plugs and fuel filter. I am pretty gutted as I'm booked into donington on sunday, so I HAVE to fix it tomorrow, argh!!
Sounds like either fuel or dodgy Power Commander. Easy test for PC is try running with it disconnected. I had one fail with similar symptoms.
Power commander's and / or their connections do go bad occasionally. That is why some of us now reprogram the stock ecu instead.
Suggest you take the power commander off temporarily to see if the problem goes away.
Was your engine number part of the Suzuki regulator recall?
Chet
I just fixed mine at 6pm the night before my donington track day. I changed the following in order first before finding the real problem, but it made
sense to do these first as a process of elimination
Plugs
Fuel filter (factory car has a corsa filter - I can always get you one bob if you struggle to find one in Spain, my motor factors down the road stock
them)
Drain tank and remove fuel pump, clean mesh(full of welding swarf which hadn't been flushed out during the initial sloppy tank build)
Battery terminal clean / charge
Then when I came to turn the car on it was dead. Kill switch connections were fine so I suspected dodgy ingnition key holder. Removed this via hot
wiring, but found issue to still be there. With the ignition on, Massaging the wiring loom behind the dashboard then produced intermittent cut outs
which had been causing my apparent missfire, in fact a combination of acceleration G and vibration had been adversely manipulating poor connector
joins in the wiring loom behind the dash. Due to the number of wires it was difficult to find, but re mounting the loom and tweaking the connectors
did the trick. All in all very happy to fix it.
Just to finish off this thread.
There's only one (in tank) fuel filter in my car, I checked with Danny.
Took it to a local Suzuki car garage and they checked the filter to find it clogged with ally swarf. Plug check revealed the gap was a tad excessive.
Now corrected. Simples!
Car now pulls like a train at all revs and in all gears.
125€ well spent.
Many thanks for inputs.
[Edited on 8/10/13 by bobinspain]
Blimey it's taken all this time and all along it was a manufacturing fault! Glad it's now sorted.