2000 GSXR-750 stalling at low speeds, running rich, etc.

[Titus Pantus]

Hi all, I bought a 2000 GSXR-750 yesterday and have got some niggles that need resolving with your help if possible. It has a K&N air filter and an aftermarket can and these may be the problem. The lad I bought the bike from said it stalls occasionally and upon riding it home it is a bloody nightmare!!

When you start it, it doesn't always stay running as in it will die straight away and can often take around a dozen attempts to start. When you are riding and pull the clutch in and change down to second or first more often than not it will die and again takes around a dozen attempts to start. When you open the throttle sometimes it will cough and splutter and then take off, not smoothly at all. When warm and the revs die, you can apply the choke to maximum and it will only bring the revs to approximately 1000 rpm, you then blip the throttle and it will idle around 4000/5000 rpm. When idling normally it hovers around 800 rpm and although I have located the idling mechanism, I can't for the life of me find the 2 idling adjustment screws. I am going to look at the FI faults tomorrow as the red light is on, I'll also check the TPS. The bike also smells like its running very rich too, could this be because of the filter and can?

Would a Power Commander or suchlike help, or even a remap?

I'm not looking for more power, I just want to sort this frigging idling issue out!

Thanks all, I appreciate it.

[Hoggs]

Hmm our bikes have the idle screws easily accessible on the side... but a cursory Google makes it look like yours are under the fuel tank?

My recommended idle is 1300 but it's not happy at that (prefers 1500) so imagine yours is really not happy at 800!

[Stu]

moved to the right section

your wasting your time checking the throttle position sensor if its not idling right as it will be reading low if its just the idle that needs to be turned up

it sounds like you could have a few faults though

the air filter and can wont make a difference to the idle

a power commander will not solve it either

if the FI light is on you should also have FI flashing on the dash

secondary throttle valve actuator's are known for going tits up on these and causing similar problems

the stalling is probably due to the low idle so try and raise that up

forget about the Throttle position sensor for now as the bike will still idle no matter how its set! once you get it running properly then set the TPS and balance the throttle bodies too

I would give it a right good service while you are at it

your idle should be set at around 1200rpm

[Titus Pantus]

Thanks Stu, the red FI light is on constantly, it doesn't flash. I will check the faults tomorrow after work. Secondary throttle valve actuator, how hard is that to fix/replace?

Hoggs, I can get to the throttle mechanism but there are no visible adjustment screws, only nuts and I'm not sure how to adjust them yet.

[Stu]

if your light acts as an oil pressure light too then I would check your oil!

it should flash FI on the dash

not sure if you can fix the secondary throttle valve actuator as its an electrical component I have never had the pleasure of dealing with one!

forget about the choke for now

you should have an idle screw on the left hand side of the bike though

[Six30]

And all the fella you bought it off told you was it stalls occasionally ... I'd be taking it back to him.

[Hoggs]

Idle screw should look similar to this.

http://i291.photobucket.com/albums/ll294/VeX86BirD/Carb%20sync/IdleAdjustmentknob.jpg

[Stu]

And all the fella you bought it off told you was it stalls occasionally ... I'd be taking it back to him.

 

and poking his eyes out with a hot poker!!!

ps the first thing I would do is stick it in dealer mode and see if there is an error code

if a C28 pops up then its definitely the secondary throttle valve actuator

I'm going to back track a bit here

dont touch your idle screw until you have checked the code and the secondary throttle valve actuator if it is faulty it can cause low idle

[Titus Pantus]

No worries, I'll check the codes tomorrow after work and see what's what. Oil appears OK through the glass.

I will also look for an adjustment screw. If it's light enough tomorrow I'll take a picture of it as I can't see it for the life of me. Off to bed now, catch up with you all tomorrow.

[Six30]

No worries, I'll check the codes tomorrow after work and see what's what. Oil appears OK through the glass.

I will also look for an adjustment screw. If it's light enough tomorrow I'll take a picture of it as I can't see it for the life of me. Off to bed now, catch up with you all tomorrow.

 

I'm feeling your pain , what with losing your key as well, hope you get it sorted mate

[fq-craigus]

Idle is too low. Flash out the codes and see what it comes up with

[Titus Pantus]

OK so, c22 fault. Atmospheric pressure sensor. Could this be what is making or at least contributing to the bike running like crap?

I'm too tired to hunt for the sensor now and its bucketing down out there so I will wait until tomorrow. Also the dash before the c is high but I literally only started the bike to get the codes. Do I have to wait for normal running temperature to get the correct reading?

Thanks all, speak tomorrow.

[Tango]

Yeah.....If that sensor is goosed it'll mess up the fuelling.......dunno where it is on the gixxer, but it's on the airbox on the Speedy......so have a look around that area.....

[Stu]

yes that sensor can and will affect the running of the bike

they very very rarely fail! so it could be an electrical connection fault

it looks likes this http://www.ebay.co.uk/itm/Sensor-Air-Pr ... SwI-BWM6KW

it should be on the left hand side under the seat unit

it will have an electrical plug and a bit of rubber hose which connects to nothing

get this fixed before moving on to anything else otherwise you could be pissing in the wind

[Titus Pantus]

Cannot find it anywhere Stu, perhaps its missing? From the looks of it the wiring has been chopped about. Anyway, I've had enough for now!! Signing of for now.............

[Stu]

it may be hidden somewhere

as I say they are usually under the seat unit you have to remove the panels to see it

[fq-craigus]

 

This bad boy

[Titus Pantus]

Aha! I looked there last night and I am pretty sure I don't have one of those though I do have the connector block it fixes to. I will look when I get home about 6:30 tonight and report back. Wouldn't it be great if this cured the awful running problems I'm having! There is only one fault on the FI at the moment. With the TPS do you adjust that with just the ignition on, or running or up to temp? Forgive my ignorance But I am somewhat of a novice still!

[Stu]

It will more than likely sort the problem out

With the tps you set it when it's running and at the set idle AFTER you have balanced the throttle bodies

You set it to the centre line at idle then just off idle it needs to move to the upper line

Balancing the throttle bodies can bring it out of spec as will adjusting the idle

So it needs to be running fine at temp throttle bodies balanced then idle set then set your tps

Doing it any other way round is a waste of time as one can knock another out

[Titus Pantus]

Thanks for the info Stuart I appreciate it. I popped home at break but couldn't see the APS under the rear cowl or under the seat. Is it going to be near the air box do you think? Fingers crossed after I sort this out it will run a whole lot better. I'm itching to get out there!!

[Stu]

99% of the time they are under the rear seat unit somewhere

there is instances of them been upfront near the headlight

you really need to get a manual for the bike and it will tell you the location of all sensors etc

[Stu]

the sensor is on the left handside of the air box at the rear

just downloaded a manual for you bike and checked

[Titus Pantus]

Thanks Stu, I have just got in after faffing around. I found it bolted to the right hand side of the frame as you sit on the bike, just before the airbox as you said. I took the connector off and cleaned it and it now runs more evenly if that makes sense. I have no FI warning lights on now which is good. The revs are far too low still and it dies if you take the choke off. I cannot see any idle adjust screw, it just seems to be nuts that can be moved?

Is there any recommended oil for my bike as it could do with topping up. The TPS still shows as high but I guess that may change when the idle is sorted.

It feels good knowing that we seem to be getting somewhere!!

The oil light is on but is that for oil pressure or level?

Also, the bike now smells like a bike when running instead of fuel!!

[Stu]

you may have a bad connection/lose wire on it

there should be an idle screw hidden somewhere

as for the oil light been on if there is no FI codes then it must be oil pressure and this is a worry to me to be honest!! its a pressure switch and not a level sensor on these

if you adjust the idle up the TPS will stay on the top bar as it moves up when you open the throttle bodies

[Titus Pantus]

Shoot! Any ideas what to do about the oil pressure then?

I think if I lift the tank again, the idle screw will be on the left side of the bike, on the right side of the throttle cables. I will go out tomorrow and do that and report back!! Hopefully I will be able to go out on it properly soon without stalling at every junction!!