Fuelling Issue?? Idle + VTECH - A bunch of weird things

Hi guys,

Have been browsing the forum for some useful information; found some tips but nothing that mimics my experience;

I have a 2012 with 96,000 kms, down in Melbourne, Australia.

Recently did an oil change, brake bleed some standard TLC got the injectors serviced. I had not changed the fuel filter in a few years so took the opportunity to do this also with an OEM fuel filter. I have also ordered a new hot idle wax unit as I think mine has been shot; on Occassion it does not idle consistently, a few months ago a mechanic messed with it and turned the adjustment nut a few turns...go figure...

Once I reassembled everything, the bike started falling over itself and sputtering badly around 6,500 -6,800 RPM's. (Side note: I will admit, the reassembly of the fuel pump assembly into the tank after the filter fitment was a bit tricky and I was not sure if shoving the last bit of the steel wool filter was the way to go but I could not get it to fit otherwise..). Because I had fit in a new filter, I suspected perhaps an incorrect assembly causing fuel delivery restrictions?

To avoid draining the tank, I thought I would have a look at the vacuum hoses to make sure there were no vacuum leaks - sure enough found the vacuum hose for the flapper valve off the intake nipple. (Should mention that the bike has had the snorkel delete, flapper mod + PAIR delete (blocked off) for a while and it was running great). Took the time to redo all the vacuum hoses with fresh silicone hoses; MAP + FPR circuits. Blocked off the flapper valve hose with an end cap so no vacuum leaks now!

After this, the power all the way through VTECH to red line seems much much better, doesn't stumble but it does occasionally hesitate between 6,500 - 8,000..almost stutters through the revs all the way to redline..Gut feeling is that it feels like a fuelling issue at this time to me...

A few other mystery items; After the bike is warmed up, I can smell what seems to be a rich exhaust... (i have a REMUS exhaust system on it (just the cans and piping from the collector)

Also the left side exhaust (standing behind the bike) feels warmer than the right side?? I tried to read up on how the collector box is made but on the face of it looks as though it is a 4 into 1 and then into 2 for the cans?
I am thinking before pulling out the fuel pump again, my FPR may be malfunctioning?

I could not smell any fuel or see any visible fuel leak out during priming with just the ignition ON? Could it be just stuck shut?

Did a starter valve sync and got a solid steady adjustment 8-9 inch of vacuum.




I really appreciate you guys helping out...really doing my head in..

 

Are all of the vacuum values soposed to be identical for the 6th gen?
I own a '98 (5th gen) and the FSM states they are not!

 

Hey RillwJoe,

Yeah..they are all referenced to cylinder 4, I set up the gauges so the one on the left is cylinder 1 and the one on the extreme right is cylinder 4.

 

Get an infrared temperature gauge, they so cheap and so handy

 

Have you replaced the spark plugs in the time that you have owned your VFR?
You might want to pull them to see how they look.

 

yes I had replaced the spark plugs a few weeks ago before I got into the fuel filter and the SVS..ran fine.


Today i noticed the rear 2 exhaust headers were cool much after the front 2. Given they were on the idle circuit I cracked the throttle and sure enough they started warming up pretty quickly. I do not think it is a spark issue because it wouldnt fire up under throttle application?

i think the mechanic screwing around with the idle unit messed things up. Even though I synced them pretty close; i am assuming perhaps the throttle bodies themselves need some cleaning? The filter had black fuel pouring out when i pulled the old one out and some of the injectors were partially blocked before i had them serviced however the bike did not seem to lack power and no issues on VTECH either....just a low end vibration..

i am considering ordering a FPR now as it could be a failing FPR? i did pull the vacuum hose again but couldnt spot any fuel there but what if it has not leaked at the diapghram but it is malfunctioning none the less? Any suggestions for an aftermarket FPR or just go OEM?

Also not sure if the throttle body has a rebuild kit? Or just needs a good disassembly and clean?


Thanks guys

 

The only path for idle air is through the starter valves, the butterflies are basically sealed shut at that point. If you've synched the vacuum then you ought to have uniform airflow at idle.

 

Absolutely. Although after I put the last post I remembered that when I had done the vacuum after the hot idle unit has done its job..I actuated the hot idle unit by hand and i noticed all valves squeaking. Not sure if this is normal and they need to be silent but I noticed some minor play in them maybe thats why they were squeaking as they were moving? I did give them a dose of WD-40 but that did not stop the squeaking...

 

Hi guys,

Been raining here in Melbourne this entire week so could not really get a long ride in but a short one in to test the work done but I did manage to get the following done:

1. Rechecked all vacuum hoses. All good there. The hose from the cylinder head to the air box was a bit loose and had a small leak so fixed that up. Bike seems to be better at the higher RPM's with a bit of an intermittent flat spot. Still not a 100%.

2. I checked the electrical. Resistances for the IAT sensor came out OK. Voltage for the MAP sensor was good. Checked resistances for the alternator all within spec and no short/ground. Idle voltage at battery between 13.8-14.0 V. At higher RPMs voltage does not climb past 14.1V so all good here.

3. I have unscrewed the nut on the hot idle wax unit as it was sticky and I felt the starter valves need some TLC. I have ordered a new wax unit from Yoshi parts and when they arrive I will take off the TB, drain the coolant and refill that and check the hoses leading up to the wax unit to make sure it is fine. Once I disconnected/de-linked the wax unit from the throttle plate and with the idle know by the clutch cover set to full clockwise, the bike idles at 1100-1000 at cold. I guess I can live with this till the new unit comes.

4. Something interesting: after all of this. I noticed that the engine, of its own accord, raised the RPM to 1,500 then to 2,000. I was scratching my head as the SV's were not pulled back and there was no vacuum leaks (double, triple checked + all new hoses all checked with my vacuum pump before installing all the pieces). Even though the harness side of the MAP sensor checked out, I thought maybe the MAP sensor was sending out the wrong information. I unplugged the connector but left the hose connected to the sensor; instantly the RPM's dropped again to 1,100 and the engine sounded as though it had more 'bass'. I reconnected and again the RPM shot up. Disconnected it again and the RPM's dropped.

I think it could be the MAP...any ideas guys

 

The idle speed will increase naturally as the engine warms up; the fuel vapourises better so you get more combustion, so I wouldn't be too suprised that 1100 cold becomes 2000rpm when warmed up.

I'm note sure that your MAP exercise shows an issue; the engine is using the intake pressure as one of the inputs to drive the injector pulse width, along with throttle position, coolant temperature and air temperature. By disconnecting the MAP sensor, you've created a fault for the FI system (expected voltage not received) so the FI defaults to "limp home" mode; it will run and be rideable, but not "right", so probably no suprise that the idle speed changed when you did that. You will probably have a flashing FI light to show it has detected a fault.

 

thanks Terry,

funny thing was it was doing it at startup like 5 seconds in..

thanks for the note on the MAP sensor..makes sense..
so i had another look. I was flashing my light to have a closer look at the starter valves and it looks as though the number 3 cylinder was screwed in the whole way so much so both holes had the metal cylinder showing through the 2 small holes on the TB. I took out the valve (dropped the brass end down the bike..dont ask how I got it back up ) anyway I fixed it up and now it looks like the same gap. I did not break out the vacuum gauges i eye balled it but looked pretty close..took into account parallax error..lol...

The bike now sitting at 1200 rpm with the idle adjuster knob about 3/4 turn counter clockwise from maximum clockwise as a rough indicator.

have not ridden her yet to figure out how she feels especially at the higher rev range.

the wax unit is on the way and I will be pulling off the TB shortly anyway where I plan to clwan the TB, dismantle and clean tbe SV's also


Any tips or advice so fae?

 

Also meant to ask; I have Remus cans instead of the stock system. It came with its own pipe to the collector box...im noticing the right side exhaust is cooler than tbe left bank..all exhaust pipes feed into the collector and then comes out as - 1 - 2 system so is this normal?

 

You are right, the exhaust is a 4-1, then splits to the two mufflers, so any temperature difference is just down to airflow difference after the y-pipe.

I have had the "oh shit, where did that go?" experience a few times. Worst was when a dowel dropped out of my fingers when I had the clutch cover off and disappeared into the sump. Fished that out with a magnet luckily, otherwise I would have had to pull the sump off (after the exhaust system).

 

something strange..as i put the seat back on, the wire bunch for the fuel level sensor and the pump grabbed the edge...this caused the rpm to rev up to 2,200 rpm...i took the seat off and started pressing it and at a certain spot it caused the RPM to go up...now i am thinking that maybe pressing the wire causes it to get a full 12 V which means that there is likely a ground or bad insulation somewhere...i am also dropping steady on the voltmeter on ignition ON for the fuel pump prime from 12.8 V to 12.3 V.....is this voltage fade on priming normal?

I think i need to investigate the harness...from the wiring diagram this pump wire goes to the fuel relay and to the common ground block?