FI specific issue with a 2001 model

[angelthing]

Hello to everybody,

newbie (to the forum) bringing greetings from Greece.

I would greatly appreciate your advise / help on an issue that has me baffled for the past few months:

My busa is a 2001 jobbie, with twin Acrapovic bolt ons, DNA air filter and a PC III usb mapped with the yoshi bolt on + free filter map suggested by dynojet tech support (as an all round compromise, had an email chat with them concerning this).
No TRE is on and I have not removed the pair valve or done the marble mod.

The bike was running fine untill about last August and then a problem developed:

It started while i was on the motorway doing about 90mph or thereabouts. It felt like there was some slight reluctance to pull cleanly for about a second or two and then the FI light came on. Bike was running ok with the light on but i pulled to the side regardless and killed the engine. When started all was fine for a bit and then it did this again.

Got me home ok, and after doing the dealer mod I found out that the reported error code was C32 (first cylinder injection issue). The bike would give me the same behaviour almost at every ride sometimes at low revs. sometime at higher revs and mostly when it got warmed up.

I have since checked the electrical wiring to the injector (as per suzuki and Haynes manuals specks), taken out the #1 injector and cleaned it, swapped the #1 and #2 injectors but still got the C32 error code.

What I still have not done is to disconnect the PC and run the bike without it, check the spark HT circuits - as suggested by a mate in the greek Busa forum - or start focusing on electrical issues like grounding problems or faulty ECM connections.

What buffles me is that most of the time the bike runs fine (and when it does there is no indication or feel that something is wrong) but it will most likely exhibit this behaviour at least once per ride.

Any thoughts or suggestions concerning this issue will be most welcome.

Regards

 

[GIXERHP]

The harness going from the ECU to the throttle bodies has either a short, or chaffed wire in it, somewhere in the line!

It happened to a buddies bike, and we found the problem towards the left back section of the tank!

 

[angelthing]

The harness going from the ECU to the throttle bodies has either a short, or chaffed wire in it, somewhere in the line!

It happened to a buddies bike, and we found the problem towards the left back section of the tank!

Cheers mate,

this would make sense. It is just the sort of thing that is gonna be a real b*****d to find though .......

Thanx for replying.

 

[mike1180]

Check what Gixxerhp said.

Welcome!

 

[GIXERHP]

Cheers mate,

this would make sense. It is just the sort of thing that is gonna be a real b*****d to find though .......

Thanx for replying.

Prop the tank up, and the harness that runs by the upper shock mount check around there!

 

[angelthing]

Prop the tank up, and the harness that runs by the upper shock mount check around there!

Right, I had a quick look and found the wiring junctions you are reffering at. Nothing is visibly wrong but I did poke around the wires and connections and used some water repellant on them. Now all I need is some better weather (it has been raining very heavily in athens) to ride and check that it was not just a loose connection before going any deeper into the wire harness.

Thanx again for the help mate !

 

[2busa]

A visual is one way, but you need an ohm meter to read if the wires are causing a draw to ground. If you probe a wire and ground the meter prong to ground, there is you problem with the wire running to ground. See, you swapped injectors, so the injector still cuts out on #1.

Sounds like a wire, no? So say we just use a color wire and say it's white. We then take the meter from one end of the clip that is snapped to the injector. We remove the throttle body main harness, find that white wire to the #1 injector.

We know there are 2 wires, but for demonstration purposes, we probe the white wire on one end, and not ground the meter probe to ground, but to the other end of the white wire. The meter will swing to infinity both grounded or wire end to wire end.

See, we are looking for one uninterrupted feed from one connector end to the other. If the white wire goes to ground, there is your strand of wire that is etching onto ground when you test the wire 3 different ways.

If the wire is broken internally the meter will not swing to infinity. If the wire swings to infinity from white wire to ground, there is your short. If the meter swings to infinity when you probe both ends, then the wire has good integrity, and now move on to the next wire at the clip and repeat the 3 variables. Something like that.

 

[angelthing]

A visual is one way, but you need an ohm meter to read if the wires are causing a draw to ground. If you probe a wire and ground the meter prong to ground, there is you problem with the wire running to ground. See, you swapped injectors, so the injector still cuts out on #1.

Sounds like a wire, no? So say we just use a color wire and say it's white. We then take the meter from one end of the clip that is snapped to the injector. We remove the throttle body main harness, find that white wire to the #1 injector.

We know there are 2 wires, but for demonstration purposes, we probe the white wire on one end, and not ground the meter probe to ground, but to the other end of the white wire. The meter will swing to infinity both grounded or wire end to wire end.

See, we are looking for one uninterrupted feed from one connector end to the other. If the white wire goes to ground, there is your strand of wire that is etching onto ground when you test the wire 3 different ways.

If the wire is broken internally the meter will not swing to infinity. If the wire swings to infinity from white wire to ground, there is your short. If the meter swings to infinity when you probe both ends, then the wire has good integrity, and now move on to the next wire at the clip and repeat the 3 variables. Something like that.

This sounds like a good plan to check for possible wire breaks in the various cable lengths (between connectors).

Thanx mate. I shall put your advise to the test if needed (hopefully my poking of the connectors yesterday might have done something good - weather allowing I shall check this out soon.

Cheers

 

[suzuka1980]

maybe you should check the FI code?

 

[angelthing]

maybe you should check the FI code?

Have done this from the beginning (see in my 1st post), the code is C32 that corresponds to problems in the cyl #1 injection.

As it was pointed out in previous posts in this topik, the problem was indeed a wiring one. It was actually a wiring issue in the power commander wire harness that has been dealt with.

Thanx again to everybody who took the time to reply.