low rpm problems

Hi.
I got my VFR800FI -99/00 couple of weeks ago and first i loved my bike but like my luck then problems started...

I don´t know does that injection cleaner cause it, but it started run extremely rough.
When it´s idleing and low rpm`s it jumps about 300-400rpm up and down.
Over 4000 i think it runs fine.
When i try to increase speed in 2000-4000rpm it jumps like kangaroo. Even first gear

If i run it high rpm some time then it runs fine about 5sec. And when it´s could it runs fine

All plugs is changed, leads is measured and those was fine.
Then i looked temperatures of each sylinder and number 1 is much colder than number 3.
Is it possible that first cylinder injector is stucked cause of that cleaner.
I try to put more of that in tank but after couple of hundred kilometers problem is still on.

 

:welcome:
I would start by checking each spark plug, I have seen bad new ones more than once. If cylinder #1 is colder, I suspect that plug is bad. Check that all vacuum hoses are connected, you wouldn't be the first to have one come loose when lifting the gas tank up. Get some carb cleaner spray and lightly spray around gaskets and hoses to see if engine speed changes. I highly doubt the injector cleaner hurt anything.

 

Well i have all ready try to change plugs again, but that doesn't make any difference.
I have to check those vacuum hoses again.. there might been problem..

But one vacuum hose is missing and in my time no one has touched it.
I mean cylinder no.1 hose witch is attached to aircleaner box. Left side should be no.1,3 and right side 2,4.
I did't see that no.1 anywhere. But i havent take that box off, so i think that hose have to go some where else.

i think that some models those all hoses go elsewhere.

 

If you have the model with the hose attachments on the air box, then you definitely need hose one attached.
But normally having hose off makes it idle higher.

 

Unless it leans it out enough to stop it from firing properly. It would make less of a difference at high RPM, where there's a lot more air going through the throttles, and less vacuum too. I'd find the hose and fix it before the engine ends up being dusted because of it.

Of course, there's also the possibility that the engine is already dusted, or the exhaust valves burnt. It could also be a combination of things, both major and minor.

 

Well i went driving today after couple of days.
i think that cleaning stuff works cause bike works fine now.
maybe that injector no1 was little bit stucked.

i think that ex-owner has done something for that hose no1, but i have to take that airbox off and find that hose.
but because bike works fine when i bought it, i think that hose is plugged.

That under peace of airbox is quite hard to take off? As i heard..

 

If you remove the PAIR valveplumbing and install block-off plates and a bung on the air box, it will become an easier job.

 

Does anyone have real picture where i can see where that vacuum pipe go in cylinder 1?
I try to look(airbox still on) but i did´t see place where it should be?

 

Best I could do.

 

Thanks for the picture, but that vacuumline problem is solved..:eagerness:
Maybe i was stupid or my knowledge is little bit weak, but i found that pipe..
It went to automatic greaser :triumphant: