Rough acceleration/misfiring TPS issue?

[LEDBiker]

I have a 2000 Busa. No engine mods or Power Commander. 35,000 miles.

Replaced the plugs, battery, air filter this year, after putting on a new TPS to replace the old one which was definitely bad. I am still having the same problem as I did with the old one but a little less pronounced. Bike starts and idles fine. Less than 1/4 throttle and it sputters and pops. Get over 1/4 and its smooth all the way up to red line, as long as I don't get on or get off the throttle. Once I do, it will sputter and break down. Any change in the throttle will cause it to sputter, but if its held at 1/2, 3/4 or WOT it will run smooth alll the way up.

I know the procedure to adjust the TPS is to jump that connector and put it in dealer mode after warming it up. The trouble is that with the new TPS, the the dash does not move at all, no matter which way I turn the TPS. The old one did move the dash even though it was bad, but it just moved the bad spot around so I replaced it. The new TPS doesn't move the dash at all. The bad spot doesn't change at all.

Could I have gotten a bad TPS? Ordered through my local Suzuki dealer so its not a chinese knock off, or shouldn't be.

Is there something else I should be looking at instead?

 

[Berlin Germany]

no in-tank-fuel-pump i suppose
but the external one, flanged RH to the throttle valve bridge

1st try - put the tps-dash (?) by the C00 gauge in the middle - it needs only a 10th of a millimeter / 1° turn step to move from C__ to C-- and C line up (the whole adjustment is very! fiddly)
2nd try - control the fuel hoses if they are kinked / narrowed - ev. the ´99 are used - get the ´00 hoses
3rd try - put the pump into its pieces and clean (or replace) the pump internal filter - but watch the item-no - the filter-form differs from ´99 to ´00

 

[Kiwi Rider]

no in-tank-fuel-pump i suppose
but the external one, flanged RH to the throttle valve bridge

1st try - put the tps-dash (?) by the C00 gauge in the middle - it needs only a 10th of a millimeter / 1° turn step to move from C__ to C-- and C line up (the whole adjustment is very! fiddly)
2nd try - control the fuel hoses if they are kinked / narrowed - ev. the ´99 are used - get the ´00 hoses
3rd try - put the pump into its pieces and clean (or replace) the pump internal filter - but watch the item-no - the filter-form differs from ´99 to ´00

Excellent info as usual Frank . . also your new avatar is pretty cool too!
Only other thing I could add is to check the fuel pressure regulator mesh screen is not blocked, and check the fuel pressure is constant through out the rev range.
Also check the injectors spray patterns for any issues re the injectors.
It really is worth the effort to go right through the fuel system start to finish on these older Gen 1's with the external fuel pump, you'd be surprised at what you may find!

 

[LEDBiker]

no in-tank-fuel-pump i suppose
but the external one, flanged RH to the throttle valve bridge

1st try - put the tps-dash (?) by the C00 gauge in the middle - it needs only a 10th of a millimeter / 1° turn step to move from C__ to C-- and C line up (the whole adjustment is very! fiddly)
2nd try - control the fuel hoses if they are kinked / narrowed - ev. the ´99 are used - get the ´00 hoses
3rd try - put the pump into its pieces and clean (or replace) the pump internal filter - but watch the item-no - the filter-form differs from ´99 to ´00

Thanks.

I'm not super great with mechanical stuff... shame I know but I do know that it is the external fuel pump. I did have problems when I first got it with the fuel lines. The bike would stall out coming off idle. They were kinking up when the tank closed so I replaced them with new hoses that didn't kink. It solved that problem at the time. I will double check those first.

With the TPS, I did have the dash lined up with the other mark. No matter which way I turn it the C00 doesn't change. A little or a lot. The dash remains at the bottom of the display. I wish I had of saved the old TPS so I could check if that still moves the indicator.

I have never taken the fuel pump off or apart. Is it a big job or complicated?

 

[LEDBiker]

Excellent info as usual Frank . . also your new avatar is pretty cool too!
Only other thing I could add is to check the fuel pressure regulator mesh screen is not blocked, and check the fuel pressure is constant through out the rev range.
Also check the injectors spray patterns for any issues re the injectors.
It really is worth the effort to go right through the fuel system start to finish on these older Gen 1's with the external fuel pump, you'd be surprised at what you may find!

Is the rest of this a big deal? Can I check all of this at home or does it need to go to a shop. The nearest shop to me is hundreds of miles away which really sucks.

 

[sixpack577]

None of what needs done is difficult.
Members here can walk you through all of it too, no worries.

 

[Kiwi Rider]

Is the rest of this a big deal? Can I check all of this at home or does it need to go to a shop. The nearest shop to me is hundreds of miles away which really sucks.

This could be quite a challenge for you to do this work if you're not familiar with wrenching on bikes.
To be able to check fuel pressure, a fuel pressure gauge is required and hooking it up is quite tricky for the uninitiated.
Anyway, getting back to your TPS,
Here is another method of testing and setting the TPS range using a multimeter set on the Ohms range..
Throttle closed.... 1.3kohms
Wide open throttle...4.5kohms

 

[sixpack577]

Hard to beat first hand info from a motorcycle mechanic at a Suzuki dealer..
especially a good one that knows what they're doing(it's sad that's so hard to come by anymore).

 

[Kiwi Rider]

Hard to beat first hand info from a motorcycle mechanic at a Suzuki dealer..
especially a good one that knows what they're doing(it's sad that's so hard to come by anymore).

Well, I have 91 weeks to go before I'm 65 and can bow out of the game knowing I have served my time, 45 years on the tools, so thanks for your endorsement my friend!
At my shop there are two other techs and one apprentice.
One of the techs is 29, a BMW and Suzuki trained motorcycle mechanic, a very good dirt bike rider, and the other is an ex speedway solo champ, exceptionally skilled rider and a very good mechanic, 26 years old.
So we do have a little hope here in NZ with new techs coming on, whether they stick it out for 40 plus years like I did . . who knows. There are very few techs like me that will go the distance.

 

[sixpack577]

Well, I have 91 weeks to go before I'm 65 and can bow out of the game knowing I have served my time, 45 years on the tools, so thanks for your endorsement my friend!
At my shop there are two other techs and one apprentice.
One of the techs is 29, a BMW and Suzuki trained motorcycle mechanic, a very good dirt bike rider, and the other is an ex speedway solo champ, exceptionally skilled rider and a very good mechanic, 26 years old.
So we do have a little hope here in NZ with new techs coming on, whether they stick it out for 40 plus years like I did . . who knows. There are very few techs like me that will go the distance.

Glad to hear you have good help.
I hope they are smart enough to listen to you.
I have watched several machinists and tool and die makers retire from where I work over the years.
Saddest part was watching 40+years of knowledge and experience walk out the door each time, and no one had been put under them as an apprentice or even for any training.
Are you going to be ready to hang it up?
I worked as an auto mechanic years ago, hated it, and eventually moved on.
But if I could make living as a tech at a bike dealer, I would be all about it...I say that now, meanwhile I b*tch about the stuff in my garage waiting on me right now, lol.

 

[Kiwi Rider]

Glad to hear you have good help.
I hope they are smart enough to listen to you.
I have watched several machinists and tool and die makers retire from where I work over the years.
Saddest part was watching 40+years of knowledge and experience walk out the door each time, and no one had been put under them as an apprentice or even for any training.
Are you going to be ready to hang it up?
I worked as an auto mechanic years ago, hated it, and eventually moved on.
But if I could make living as a tech at a bike dealer, I would be all about it...I say that now, meanwhile I b*tch about the stuff in my garage waiting on me right now, lol.

I’ll PM you to further this discussion and to de-hijack this thread lol

 

[BlueBacon]

I'm not super great with mechanical stuff... shame I know but I do know that it is the external fuel pump. I did have problems when I first got it with the fuel lines. The bike would stall out coming off idle. They were kinking up when the tank closed so I replaced them with new hoses that didn't kink. It solved that problem at the time. I will double check those first.

I have never taken the fuel pump off or apart. Is it a big job or complicated?

All of it is easily a "1 person-1 day" job. I removed my internal fuel pump assembly this year to drill a hole and add an external fuel filter. There is a post from @SSGT_B (that I cannot link for some reason) showing how he cleaned out his injectors when he did his fuel filter mod.

 

[LEDBiker]

Thanks a bunch Kiwirider, I will do that.

I was away for work and just back. Randomly I was messing with the TPS and its in a better place than it was. The hesitation and weirdness is about half of what it was. All I did was randomly change the position by a hair and it works better. However, I will use the method you suggested above.

We only have a few more weeks of riding left here before snow flies but I'll take apart that fuel pump over the winter, and a few other things.

 

[LEDBiker]

All of it is easily a "1 person-1 day" job. I removed my internal fuel pump assembly this year to drill a hole and add an external fuel filter. There is a post from @SSGT_B (that I cannot link for some reason) showing how he cleaned out his injectors when he did his fuel filter mod.

Thanks!