Power loss at 9k RPM

[Johnnycheese]

(Johnnycheese @ Jun. 16 2007,15:59) I say the cam jumped a tooth

he says it is fine

 

[BA BUSA]

(Big Red @ Jul. 07 2007,20:20) New cams; what about valve train problems?

His engine was rebuilt about 35,000 miles ago...the cams were put in them

It is only recently that something has gone amiss

 

[Big O]

She's FIXED!!!!

The wiring harness seemed to be the problem. I don't know what part of the the wiring harness yet, I'll have to do a autopsy on it to find the wire that was bad.

To review, we changed:
Throttle body, (includes injectors)
Ingition coils
Spark plugs
Ingition rotor,
Cam sensor
Fuel pump (includes fuel filter)
Crankshaft sensor
MAP sensor
Barometric sensor
checked fuel rail, and all vacuum lines.
Checked conductivity on ALL electrical wires (even turn signals)
Suzuki Techs were stumped.

I'm not sure if this will help, but it may be a place to look if you have the same exact problem.

 

[Big O]

(stlbusarider @ Jun. 15 2007,17:01) If the FI light is coming on still after replacing the cam sensor you should have your tech use an occiliscope and ck the wave form on the sensor at 9k rpm. If he's as good as you think, he'll know what that means. If the wave form is erattic you may have a problem with the ring on the cam.  Hope it helps, ggod luck.

20/20 hindsight, I think this might be an easy check. Is it possible to check the other wires like this? Do you have to dissconnect the wires or can it be done with an induction sensor. Like a timing gun has an induction pickup?

 

[stlbusarider]

You can only ck sensor that send an a/c signal or d/c signal to the computer, the tps,ect,iat,cam sensor, crank sensor, ect. The ocilliscope is a digital reader of the low amp voltage wave put out by these sensors. You need to be an exprienced tech and have a good knowledge of an ocilliscope and how to use it. In the testing of a cam sensor it will show a square wave pattern as the TDC spot on the cam is reached, as RPM increases the wave form will get closer together but remain the same height and depth. If its not there is a prob with ring or sensor. As far as other sensors such as the TPS (throtlle position sensor) which are potentiometers, the wave for will be a constant rise in voltage as the throttle is opened from closed to wide open. Hope it helps. If something didn't make sense ask. (The downside of being a Tech for 15 years)

 

[dwnhllthng]

CONGRATS BIG O!! Now I beleive I will start with teh wiring harnes to see if indeed we had the exact sam problem. Any ideas from anyone where I could get a new wiring harness for a decent price...I was loking on ebay and they range from $100-250 so far...but I beleive I should buy a new one incase those harnesses are bad already.

 

[Big O]

I think the only check I can do is to remove the electrical tape and sheathing from the harness and try to find a break in the wire(s) some where. Or a bad solder maybe.

dwnhllthng -I would get a new harness just in case.

 

[Charlesbusa]

Congrats Big O!!!

Glad she's fixed

Who knows, it might have been a shielding problem too...

 

[dwnhllthng]

Best place to get a Wiring Harness NEW straight through Suzuki?

 

[Johnnycheese]

so is it really fixed?

 

[Big O]

Yes it's really fixed. Now get THIS!
The cam chain guide is worn out and I need a new cam chain and guide.

She was making noise two days after she was fixed. and she was fixed.
Maybe she heard I was looking at the 08 Busa, which by the way is in the latest Motorcyclist mag. The new one looks NIIIIIIiice.

 

[dwnhllthng]

Still working?

 

[dwnhllthng]

So Big O how does it feel to be able to hit a rev limiter again? I'm taking my bike in weds to get the wiring harness checked out/replaced

 

[Spudley]

O,

I can't tell ya where, but someone else had this problem nailed down and repaired. Something about the timing sensor, and a keyed-something off of the crankshaft

?......kept hitting the rev limiter prematurely....topping out / crapping out, that sort of thing. Identical.

Let me look, it's here in the posts somewhere.........

 

[Spudley]

Nevermind...I guess it was the harness

?

 

[dwnhllthng]

Well Big O I just did a search for a new wiring harness and its cost is $501.32.....did you happen to find out which part of it went bad causing this problem? If not I'm about to have my shop tear into mine to find out so I may not have to spend 500 bucks.

 

[Big O]

I did an autopsy on the wiring harness and the only thing I could find was a worn wire going to the ingition coil.
You can see the electrical tape is broken. It was like that, brittle and cracked.

 

[Big O]

Here's a pic of the whole wiring harness.

 

[Big O]

The four plugs at the top of the pic should be the ignition plugs, just below that is where the electrical tape is missing and the wire is worn.  I think this was the culprit.  Maybe you can look here to see if you have the same thing.

 

[Big O]

The cam chain guides were replaced. Along with the cam chain. Also found: cracked clutch cylinder cover,(with the gear position numbers) cracked exhaust header, replaced. And we put new stiffer (than stock) valve springs. Now she really sings.