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Discussion Starter #1
Hello!

2007 R6 (FI), 25k miles. Can't quite figure out this problem, but I've been doing a whole lot of testing trying to recreate the scenarios that it will die. The engine will die/stall/shutoff if I quickly pin the throttle all the way back. It does fine if I'm slow turning the throttle all the way to open. Any time I try to quickly shift during full acceleration, it will die, I think because of the quick 100 > 0 > 100 throttle movement. It will also die when I'm just cruising and quickly pin the throttle back. It doesn't matter what gear I'm in, it will even die in neutral if I pin it really fast. The check engine light will always come on when it dies, but sometimes it will come on without actually dying if I'm right on the edge of pinning it too quickly. No code is displayed. I can pretty quickly get the bike started again by clutching, cycling the key slowly, and releasing the clutch again.

Trying to chase this down, I've already tried quite a few fixes. I removed the power commander (a slip-on is the only difference in the exhaust). I just did a valve adjustment since it was almost due anyway, I got all valve clearances within spec and pretty close to nominal. Confident I lined up the timing right. I replaced the fuel pump and fuel filter. I replaced the entire throttle body, primary injectors and sensors. I gapped and then fully replaced the spark plugs. I removed the AIS and closed off all the ports since there were some cracked hoses in that assembly. Otherwise all hoses/lines look in good shape, and all gaskets look good and seated with no fluid leaks.

Anyone know what else I might be missing?

Thanks, Joe
 

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Discussion Starter #3
is the fuel lines getting pinched when the tank is lowered into position?
I don't think so? It's hard to completely tell but I made sure to clear out anything in the way for it to pinch against unless it's just kinking on its own... Good suggestion though, I'm going to find a way to look up in there while the tank's down to see if that line is getting kinked. I have a feeling that at this point it's something stupid easy like that lol
 

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Discussion Starter #4 (Edited)
It's not pinching up against anything :confused:

One weird thing I noticed: since I replaced my fuel pump, when I disconnect the main line (tank>FI rail), fuel squirts out at high pressure for a half second all over the place. It didn't used to do that.
 

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YZFR6... ooodles of HP
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It is supposed to leak when disconnected. Ohm the coils.
 

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Discussion Starter #6 (Edited)
Yea it used to drip when I disconnected it, now it literally just sprayed me in the face like I'm riley reid... at least I know the pump is providing good pressure lol

Coils measure 2.1-2.2 ohms primary resistance, which is out of spec (1.19-1.61), but I think that's just because I'm using a 2-wire multimeter which isn't taking the resistance of the leads into account, I'd need a three-wire to properly measure that low of a resistance. 9.6-9.8 kohm secondary resistance, in spec (8.5-11.5)

I just ordered some soft tubing and hose clamps to try replacing the main line, thanks to one day shipping i can try it out tomorrow :)
 

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Discussion Starter #7
Okay I think I just didn't have good contact when I measured them the first time, I measured them again just now and they're 1.6 across all 4. Resistance when I touch the leads together is .2 so I think the actual measurement is around 1.4, middle of spec
 

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Discussion Starter #9
Well, I replaced the lines with a suggestion I saw from another old post on here, wrapping soft tubing in wire. I'm 100% sure this didn't kink or pinch, but still having the problem, so I changed it back to the oem line. Pics attached.

I really have no clue what's wrong now. It really throws me that the CEL will come on right before it would die, like it knows something's wrong but it isn't telling me what it is lol.
 

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Discussion Starter #10
Okay, update time. Still experiencing the consistent CEL/shutoff on any quick throttle application, including quick shifts. I'm also now noticing some uneven power delivery at all throttle positions. I.e., sometimes at half throttle it'll be jerky, and sometimes it will bog and hardly give power for half a second until I really pull back on the throttle and then it will seem to "catch up". The acceleration response is inconsistent so it's really hard to have smooth throttle control.

The problem seems to be slowly getting worse over time (I've had this problem for about 10 months / 4k miles now). Perhaps it will eventually get to the point it will be easier to diagnose. In the meantime I feel like I've just been throwing parts at it to try to get anything at all to improve :/
 

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Discussion Starter #11
Update time again.

Throttle response has just been getting worse and worse. Extremely jumpy. Will sometimes die at low RPM. However it finally threw a code a few days ago when it died at idle - code 15 for throttles TPS open/short circuit. Obviously that's wrong because an open or short would mean the bike can't run. Since I have two throttle bodies/TPS assemblies that I've tried, I think that means a problem with either wiring or ECU, or I just got really unlucky and two TPS's are bad.

I want to diagnose wiring first, but I'm not sure what I should be measuring. Tips?
 

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YZFR6... ooodles of HP
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Check resistance of wiring and check pins for corrosion.
 

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Discussion Starter #13
Did a bunch of testing today. I think I can rule out wiring. Tested resistivity/continuity on all the TPS connections and bent the wires back and forth to make sure there wasn't anything jumping contact. I ran through diagnostics D1 and D13 and found something interesting. They're both in spec on the low end, but well under spec on the high end, measuring in the low 60's when wide open at the grip. So I took it down to the TB again and the servo motor is doing really weird things in response to the throttle applied. It will only open to that 60% or so in response to the throttle applied, no greater. If I quickly open/close the throttle grip, the servo stops completely. Just closes off to zero and won't respond unless I cycle the power again. I swapped it out with my other TB. Same exact response. For both TB's, if I manually turn the butterflies to full open, D1/D13 both read in spec. So it can't be sensors either.

Would I be correct that this has to be a faulty ECU then, since I think I've exhausted all other options? Considering that's such a pricey OEM replacement, do you guys have any tips for how to diagnose for sure that it's a faulty ECU? How bad of an idea is it to buy used or off ebay?

Edit: Wanted to add that the servo is not resisting finger pressure when applied to open. I can easily push the butterflies back down (it will be all fluttery) with the throttle grip full open.
 
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