Thread No. 6 :(. 2000ry Rough Idle Below 3000rpm, Misfire At 9000rpm Onwards. Help!!!





#1
Hello again all.

I wish I could say I'm new to the site but unfortunately, I still haven't got to the bottom of my bikes running problem.

This is my 6th thread (5 too many).

First problem-: The bike is fouling no. 2 and 3 plugs, when the throttle is opened from tick, over upto 3000rpm, it feels like its running rich, once it gets past 3000, the rev counter needle flicks up fast and feels like other cylinders have kicked in, that's the low rpm problem.

Second problem-: In about 3rd gear with the throttle pinned back the bike gets to about 9000rpm, then starts stuttering/holding back (feels like lots of misfires) it brings up C26, misfire on no.3, I also managed to get C25 too, misfire on no.2).
The bike feels underpowered, it won't lift the front on the throttle, which I know it should, I only weigh 11.5stone 76kg.

Ok, things I've tested and changed (deep breath)-:

New timing chain (today)
Timing marks are now lining up better
Cam chain tensioner has had the mod done
New fuel pump (holding 43psi during priming, cranking and accelerating upto 5000rpm)
New temp sensor
New cam position sensor
New plugs
New injector filters/shields
Checked that all injectors are squirting same distance
New piston rings fitted (ring gaps all fall within book spec)
Head and cylinder section, skimmed and checked
New .40 cometic headgasket, allowing/compensating for skimming work
All valve clearances are within book spec
Compressions done, all 4 cylinders are 175psi (checked again today)
Leak down test, holding same pressure across all cylinders (checked again today)
Tried another wiring loom/harness
Tried another TPS (set up in dealer mode -00)
Synced throttle bodies (various times)
Running with standard Suzuki exhausts (also tried with race cans)
Tried another side stand switch
Tried another ECU
Tried another rectifier
Tried another gear position sensor
Tried 2 other 'boost' sensors (IAPS)
Tried 3 sets of coils (second hand coils)
No power commander fitted
No alarm on the bike


I've been told that setting up the TPS on the bikes dashboard isn't accurate enough and it's position is critical, by a Suzuki technician, he said that it would make the bike misbehave at high rpm, if it was not exactly in the right position, can anyone confirm this?
I haven't been able to change my crankshaft sensor, could a faulty ckps cause my running problems?
I haven't changed my injectors but have swapped cylinder no. 3 to no. 4 but still it brings up no. 3 misfire, so I thought that this would eliminate a faulty injector on no. 3.
I pull the coil leads off one at a time, on tickover and revs change on all cylinders but not dramatically, just enough to notice a change.
Bike is not overheating or pressurising, temp needle stays just below halfway and fan cuts in how it should.
I get no codes up until I force it up beyond 9000rpm or leave a sensor disconnected.

It consistently has issues with no. 2 and 3 cylinders.

The bike has done 40,000miles, owner had it from new (16 years, I'm the second owner), oil came out like tar on first oil change I did.
The bike had been parked up for over a year (which he neglected to tell me on picking it up), so I think it had a running problem when he sold it to me.

On removing the cylinder head the first time, we found excessive valve guide wear, this explained 3 cylinders not holding pressure on a leak down test, I sourced another head from a bike that had done 16,000miles and now leak down test checks out ok.

I've had this evasive problem for 2 years now, just want to find the problem, I'm loathed to give it to a garage because I've tried so much already.
I'm at a bit of a loss now, ive run out of ideas and things to test/replace/change.

Hope someone can offer a suggestion or two.
Dave.
 
#4
My bike is a gen 1 2000 model.
Are you talking about a catalytic converter?
My down pipes bolt straight to the head, I'm not aware of anything that could melt, it's also misfiring, not backfiring, I'm not getting any bangs from the exhausts, just lack of firing at high rpm and low power throughout the Rev range, under load.
Thanks for the input though, I'm appreciative of any advice or ideas
 
#5
Ya thought was a 07. With a catalytic converter miss firing causes fuel to go down exhaust and will melt them. Then the motor can't breath.

Well good luck you have check marked a lot of things and diagnosed so much.
 

VIPER

Formerly known as viperblackbusa.
Registered
#6
David i dont think the bike would run with faulty crank sensor so i dont think that is it. So the problem is always number 2 and 3 cyl? No matter what you change around. Even with new head? You have tried new wire harness as well does that include the wires leading to the injectors? did you leak test the injectors? Are they holding the required amount of pressure till fire? Let me ask this as well, did someone switch out the charging system and upgrade the ecu from stock? The newer model of gen 1 use a different ecu than the first couple of years. If somehow the original owner swapped and didnt make the required changes .....
 

sixpack577

Top Gun
Registered
#7
Do you know anyone, or any shop with a 2000 Busa?
Ide want to double check that the 2nd ecu and other parts work.
As many problems as you'very had, maybe a bad part has unknowingly been replaced with a bad part.
 

GIXERHP

ok, ok...just a wee bit Irish...
Donating Member
Registered
#8
Only thing left is the injectors, are dirty, and need to cleaned and flow checked. They could be leaking and causing a rich condition

Do you have a Dyno near you that they could run the bike and Sniff it to see what is happening?
 
#9
...As many problems as you'very had, maybe a bad part has unknowingly been replaced with a bad part.
This is what I was thinking while reading his OP.

I know I won't be of much help, but man, it's difficult to comprehend that you have replaced all of that stuff without finding a solution, particularly the fact that you have already tried a new ECU and a wiring harness. It seem like you almost would have to have already replaced the faulty part, just coincidentally you replaced it with another faulty part.

In one of your older threads, you have a video where one (or more, can't recall) fuel injector was 'squirting' more than 'spraying'. Is that still the case? Maybe somehow that squirting pattern is such that, combined with >3000RPM, the stream of fuel is entering the cylinder in such a way that it is causing that cylinder to have an askew A/F mixture?

When you have a spray bottle that can do either 'spray' or 'squirt', you know, when you 'squirt' water it has a lot more velocity than if you spray it, and when it strikes a surface, you get a ton of overspray. Could something like this be happening inside your cylinder? Where the fuel is sorta bouncing around and not making it completely into the chamber during the intake stroke? We know I'm no mechanic, but I'm sure they design injectors to spray a very specific way. Plus I just want to chime in with any input considering how much you've given me.

If money permits, maybe find a local shop with a guy who is good with Busas, or maybe some dyno time would help determine the cause?
 
#10
Hi all, I've been on the road driving, all day today.
Really appreciate all the suggestions, I've just stopped and will respond to each one, once I've got coffee, it's now 11.40pm uk time.
I've never lost hope and know it can be fixed but I've never had a problem so hard to fix before, I'm not a rich person, hence a lot of second hand parts being used/swapped out.
Anyway, I'll respond soon.
Thanks again
 
#11
David i dont think the bike would run with faulty crank sensor so i dont think that is it. So the problem is always number 2 and 3 cyl? No matter what you change around. Even with new head? You have tried new wire harness as well does that include the wires leading to the injectors? did you leak test the injectors? Are they holding the required amount of pressure till fire? Let me ask this as well, did someone switch out the charging system and upgrade the ecu from stock? The newer model of gen 1 use a different ecu than the first couple of years. If somehow the original owner swapped and didnt make the required changes .....
The Haynes manual mentions a faulty ckps in the trouble shooting section, at the back, under 'poor running at low speeds', I was also under the same impression, that the engine wouldn't run (fire and die) with a faulty ckps but Im willing to entertain anything, that I haven't changed yet tbh.
Yes, swapped the short injector harness, along with the main loom.

Update with regards to no. 2 and 3 cylinders, on swapping a couple of coils, from one of the other sets I have, the codes came up as 1 and 2, at high rpm, which is possible progress, it could mean that I have 3 sets of dodgy second hand coil (would be just my luck lol).

I have tested the injectors out of the bike, operating the solenoids and holding pressure against them, open and shut but didn't pay attention to leakage ( it was my first time doing this).
Another interesting point you make, about the later gen 1 ECU, that I didn't know because on converting my bike to the in tank pump set up, I changed the throttle bodies, is it possible that my throttle bodies are not compatible with the earlier original ECU on my bike, tps not sending the right signal to the ecu, in any position for e.g?
I don't know what year bike the throttle bodies came from, that I fitted, also, is it possible that the injectors are wrong for my ECU?
Remembering how the bike was when I went to collect it and judging by the owner, I'd say that the bike had not been changed from original set up, in any way, except for the cam chain tensioner mod.
Definitely some useful new information, thank you viper.
 
#12
Do you know anyone, or any shop with a 2000 Busa?
Ide want to double check that the 2nd ecu and other parts work.
As many problems as you'very had, maybe a bad part has unknowingly been replaced with a bad part.
hi sxpack.
I'm afraid no one I know has a busa like mine (theyres all work hahaha, joking), I don't know anyone, that would let me pinch parts to test, I'm one of those 'lonely no friends' bikers :).
Shops my way, would tear me a new one, with labour charges, maybe just booking it in, to plug it into a computer, to point to where the problem might be, is worth considering but my stubbornness and suspicious nature, makes this a worst case scenario, I feel that I have all or most of the pieces of the puzzle, just need to put them together, a garage will just mainly do what I've been doing, my problem could be an incompatibility issue with different year parts, I've been fitting or like you say, fitted faulty parts, with other faulty parts, on swapping the other ECU, I get exactly the same symptoms, so I'm pretty sure the ecus are ok.
I'm hoping that it's just coils, as there's a big ? Mark over all 3 sets at the moment.
Thanks for the input sixpack, hope to have some news on a decent set of coils, next week.
 
#13
Only thing left is the injectors, are dirty, and need to cleaned and flow checked. They could be leaking and causing a rich condition

Do you have a Dyno near you that they could run the bike and Sniff it to see what is happening?
Hi gixer.
Injectors also have a ? Mark over them because of possible incompatibility or like you say, fuel leaking past while closed, this could certainly cause the rough idle and before 3000rpm but would it explain low power and high rpm misfires?
I've tested them and posted the video in another thread, while attached to the bike but it's possible I'm reading the results wrong the only thing I'm sure about, is the fuel pump condition and pressure.
I'm looking at eliminating coils first and then will probably go down the injector path.
Thanks for the suggestions, hope to have some news next week.
There are people around that have dynos but I don't see the point in a dyno run for £250, when I know that certain replaceable items, may be at fault, I'd rather spend the money on them first.
I can't say if it's overfueling or just on insufficient spark or ignition timing is out because of a faulty ckps, so I think a co test would be inconclusive at the moment but I think it's a good idea to ring up a dyno and have a chat with someone, they might have some suggestions.
 
#14
This is what I was thinking while reading his OP.

I know I won't be of much help, but man, it's difficult to comprehend that you have replaced all of that stuff without finding a solution, particularly the fact that you have already tried a new ECU and a wiring harness. It seem like you almost would have to have already replaced the faulty part, just coincidentally you replaced it with another faulty part.

In one of your older threads, you have a video where one (or more, can't recall) fuel injector was 'squirting' more than 'spraying'. Is that still the case? Maybe somehow that squirting pattern is such that, combined with >3000RPM, the stream of fuel is entering the cylinder in such a way that it is causing that cylinder to have an askew A/F mixture?

When you have a spray bottle that can do either 'spray' or 'squirt', you know, when you 'squirt' water it has a lot more velocity than if you spray it, and when it strikes a surface, you get a ton of overspray. Could something like this be happening inside your cylinder? Where the fuel is sorta bouncing around and not making it completely into the chamber during the intake stroke? We know I'm no mechanic, but I'm sure they design injectors to spray a very specific way. Plus I just want to chime in with any input considering how much you've given me.

If money permits, maybe find a local shop with a guy who is good with Busas, or maybe some dyno time would help determine the cause?
Lol that's true Shaun, I thought I would've accidentally changed the faulty part by now.

That's interesting what you say about the spray/squirt pattern, after I changed the fuel pump and got full pressure back, the amount of fuel delivery on each pulse has considerably increased, it's possible that faulty injectors, could now be pumping too much fuel, causing flooding at low rpm and leaking or failing at high rpm, it wasn't something I had considered, weak points tend to travel down the line when things are renewed.

I'm lacking any busa specialists down my way I'm afraid, I feel like I'm turning into one tbh lol the only specialist in the uk with a non running busa, I think with this new thread and new advice, there may be some light at the end of the tunnel, I was quite desperate when I posted this thread but now feel optimistic, I just really want to post that update that IT'S FIXED and say what the component was that was causing the problem.

Have you had any luck with your problem btw?
 

GIXERHP

ok, ok...just a wee bit Irish...
Donating Member
Registered
#15
I just know what we found on a older Turbo bike,, never thought you would have to this far,,, The injectors are a big question now,, They have various problems that could be your problem
 
#17
I can't follow everything that has been tried or changed. But here are a couple of facts that may help: 99-00 Busa has a different harness AND connectors to the TB than the 02-07. Plus,You can't swamp in a newer wiring harness and keep the 2000 rotor/ECU without a repin of the newer harness. (IIRC, 4 wires have to be switched). You shouldn't be able to plug in a 2000 TB plug into a 02-07 harness.

Next, sometimes a "weak" cam sensor will cause all kinds of oddities. Primarily, the cam sensor is used to start the bike and then is ignored by the ECU unless it is showing a 180 degree phase differential. The way to check is to start the bike and then once running unplug the cam sensor; run the bike up the rpm range past 9000 and see if the miss fires go away. If the bike clears up, then the sensor is bad. Now remember the bike will not start with the cam sensor unplugged. Sometimes folks describe it as a rev limiter coming in early when the cam sensor is bad.
 
#18
Hi Ransom.
I've done so much, that I've probably tied myself in knots a lot, I'm more concentrating on the things that I've changed for new, like cam chain, plugs, water temp sensor, head-gasket, piston rings, for eg, tests and checks that I know are accurate, like, compressions, leak down test, valve clearances, fuel pressure test and now focus on the things that have not been confirmed as 100%, like injectors and coils.
The second hand loom I have, plugs straight into my original TPS, so I'm sure the loom is compatible the same as the one on my bike.
I have fitted a new cam shaft sensor but will perform the test that you've suggested, I have to take the bike on the road to run it upto 9000, it does feel like a very rough and uneven rev limiter kicking in but brings up misfire codes, rev limiters don't bring up any codes.
Thanks for this ransom, a useful piece of information and test easy to test (as long as there are no speed cameras out).
 
#19
Also ransom, do you know if it's possible for a faulty ckps to give these types of faults? I know that usually a vehicle won't run, if the crank sensor is faulty but my Haynes book mentions it, in the trouble shooting section, at the back of the book, as a cause for poor low speed running issues and my local Suzuki dealer mechanic, has said that it's possible, it is one component that I've never changed and can only do a resistance check on the book says, to measure peak voltage, it needs to be given to Suzuki to test, which is bogus and I can't find anyone selling just the ckps, it is always with the stator windings.
 
#20
I've only seen one issue with a ckps. When the bike got warm, it would miss and cut-out. The fix was to isolate the crank sensor wires from the stator wires. The stator wires can cause all kinds of havoc on the crank sensor signal. The 2 ckps wires and the 3 stator wires share the same loom. You just have to separate them out and tape them.
 

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