G"day fellers,
My name is John, I have had my 00 busa since 03 (bought at17,000k) and now has 63,000k on the dial. Had a power commander pc111 usb fitted at 30,000 and bike has been un-faultable untill after the 48,000 service when it developed a surge/hesitation, this started a few rides after the service and came in at 100-110kph at steady highway speed and felt like someone was pulling back and fourth on the grab rail.
I have had it back to suzuki numerous times, they done?-re-sync throttle bodies,clean injectors,check fuel system,try new TPS and another set of plugs, after a while of going nowhere I decided to have a bit of a look myself and within ten minutes found that the throttle bodies where totally loose ( probably from 48k service)so I had suzuki redo all the checks at their expence and hoped the problem was gone.
But no luck so I pulled fuel pump and split to find the origonal filter split in two halves and full of shit (well done suzuki) so replaced filter cleaned all screens and run bike with remote fuel tank and pressure gauge to find all OK, reassembled and tested- still surging.
Bought new TPS, air temp sensor air press sensor , map sensor and coolant sensor and yes still surges.
Had the powercommander on and off and the surge is still there and I have had the mapping moved everywhere but nothing will restore the light load drivability it is slowly getting worse to the point now where the bike is far from a joy to ride and any rpm between 2500 and 4000 is lurchy in any gear but hit the noise button and its action stations to redline.
I am wondering if an ECM problem could cause this, any ideas would be appreciated (a loan of an ECM for an hour would be a great diagnostic help)
Thanks John.
You said you ran the bike with a remote fuel tank and problem was gone is that right?? What fuel pump did you use when you did this?? Was it the intank one that you used or another one??
Hey dude,
You said Suzuki cleaned the injectors??? Did they actually REMOVE them from the engine & send them off for flow testing & cleaning plus replacing the rubbers? Because if they didn't do that they didn't clean them at all! If they did this they should have provided you with a picture of the flow test from the injector cleaning.
Second thing, check for any play in the rear wheel HUB! My 2000 is up to about 67,000km. I have/had the same problem. I got my injectors pulled & sent off for cleaning & everything else that comes with it, it helpped, but it did show wear with injectors 1 & 4. I also had to replace the cushion rubbers in the rear hub. If you haven't checked this you should. If you have a rear stand just pop her up on there & with the vike in gear, see if there is any play - ie move the rear wheel. There shouldn't be any - if so - replace the cush drive rubbers ;) solved my issue.
Oh I should also mention the surgyness I have is in the same rev range, but is gone by 3,500rpm approx.
Also one of the best ways would be to get it on a Dyno & see what the A/F is like... which you would have done with the power commander right? or are you playing with maps on the power commander with out the dyno runs?
How many filters have you found in the fuel system, checked fuel pressure at these rpms ?
also look for splits blocks or leaks in the vac tubing.
Hi John,
The problems with the external fuel pump models (99 - 00) have been talked about since 1999.
Yes, you can clean the injectors, replace the filters, toss out the regulator screen, clean the injector filters, clean the fuel tank strainer, check all the vacuum hoses for kinks and holes and even drain the gear box strainer.
All of these contribute to the fuel starvation problem and surging to various levels.
Even using high octane fuel in hot weather causes vapourisation.
BUT the one thing that reduces the condition more than any is the replacement of the stock fuel lines with proper reinforced fuel injection piping for both the input and return from the tank to the fuel pump.
The OEM lines work well when they are new and when they are installed at the correct orientation, but if they are soft or twisted, they will kink and seal off as soon as the bike gets hot.
The surging condition you describe is exactly what I found happened with the OEM return hose was twisted on the tank sprogett.
It causes back pressure through the fuel pump and then a vacuum when you back off.
I've been there and worked through every one of the suggested causes.
Sorry Raz, the rear wheel cushes being worn don't cause the engine to surge.
BUSGO Wrote:Hi John,
The problems with the external fuel pump models (99 - 00) have been talked about since 1999.
Yes, you can clean the injectors, replace the filters, toss out the regulator screen, clean the injector filters, clean the fuel tank strainer, check all the vacuum hoses for kinks and holes and even drain the gear box strainer.
All of these contribute to the fuel starvation problem and surging to various levels.
Even using high octane fuel in hot weather causes vapourisation.
BUT the one thing that reduces the condition more than any is the replacement of the stock fuel lines with proper reinforced fuel injection piping for both the input and return from the tank to the fuel pump.
The OEM lines work well when they are new and when they are installed at the correct orientation, but if they are soft or twisted, they will kink and seal off as soon as the bike gets hot.
The surging condition you describe is exactly what I found happened with the OEM return hose was twisted on the tank sprogett.
It causes back pressure through the fuel pump and then a vacuum when you back off.
I've been there and worked through every one of the suggested causes.
Sorry Raz, the rear wheel cushes being worn don't cause the engine to surge.
Thanks for all your Quick replys( I have never had one from SAPL yet )
I have replaced both fuel lines with oem new ones, done the cush drive rubbers and even replaced a perfectly good set of sprockets and chain for new( on advice from suzuki)
no I never saw any flow charts for the injectors although suzuki told me they took them out?
I have cleaned all 7 of the screens and bought a new "golden' internal filter.
This problem did not creep into the bike it just suddenly happened shortly after 48k, it used to take at least 28km of riding before it would start and it would be in for say50% of a ride( you could ride 30 or 40km fine and then get on a highway stretch at100 kph and it would arc up and then stop again after maybe 5km and run fine for another stretch)
Now its getting to the stage where its hunting all the time at light throttle, all the mapping changes have been done on a dyno in fact the same one which set the pc3 up initially and it ran fin for a couple of years ( dyno is Serco's Dynojet Dyno so it can upload straight to the pc) although I think a problem in diagnosing light throttle problems on a dyno is that the dyno puts too much rolling resistance on the bike and masks the issue, I have been an A grade auto mechanic since 74 and have often found limitations on dyno results i.e. my bike has gon from 156 to 160rwhp in the course of trying to solve this issue but it still runs like a pig.
thanks again for your imput
John White
Still sounds like a lean surge , can you put in 10% at that range and see what it does, always revert back if needed.., still suspect a fuel pressure issue untill checked as ok.
Most sensors will give a fault code if not within range
j.white Wrote:Sorry Raz, the rear wheel cushes being worn don't cause the engine to surge.
Your right it won't cause the engine to surge, but it can make it FEEL like it is or has slight pause before power comes through... but thats only due to movement in the hub :) hope you get it sorta mate!
I guess being a sparky you would have already checked your plugs, caps ,leads coil's etc ? I had a bike with a similar fault and was positive it was fuel ,but in the end it turned out to be a simple ignition problem.
Mine developed a surge and a flat spot on accelertion, very recently. Most noticeable at about 100kmh in top gear and very light throttle. I pulled all the electrical connections apart(from the injectors to the ECM connectors and everything in between, there are quite a few connectors) and sprayed with an aerosol electrical contact cleaner. No more surge!
My bike some times has a power surge,
When you hit 25# boost on a good track and it carries the front wheel over the finshline......hehehe
Leonard.
Legend Wrote:My bike some times has a power surge,
When you hit 25# boost on a good track and it carries the front wheel over the finshline......hehehe
Leonard.
funny prick hey I was gonna say that mine surges around the 125-135k mark but I know what my fault is it is telling me to either slow down or lift the front wheel
Thanks again for your imputs,
I have opened up all the electrical connectors and sprayed proper contact cleaner on them ( as previously read on this site a while ago) as well as disconnecting the ECM to re-set any memory.
Why I was asking if anyone knows of or has an ECM to try is that in the 2000 service manual under troubleshooting as well as in the diagnostic sections they always say "replace ECM if all else fails, the ECM puts out codes for everything that fails on the bike but what puts out a code for a corrupt ECM ? Does anyone Know if 99 & 00 ECM's are the same?
Thanks John White.
Remember "Its hard to remember the object of the exercise was to drain the swamp when your up to your ass in alligators".
99 and 2000 ecu's are the same......but, I've got a late 2000 plated busa thats actually a 2001 (has in tank pump different harness etc).
If your pump is outside then 2000 it is.
If you have no luck with ecus, I'd be willing to try your ecu in my 99, if that helps.
Leonard.