I'm in a shop clean out phase right now. As such, I have a bunch of GSXR parts listed on FB marketplace. As you can imagine, this brings out some characters.
3 days ago I was contacted by a guy (who had actually contacted me a month or so ago about an oil pan and stopped responding abruptly), he asked if I had a starter clutch. As it happens, I had a disassembled motor, and therefore I did have the starter clutch he needed readily available. Shot him a pic and told him $20 and it was his. To my surprise, he said he was on the way over. Cool. When he arrived, it was him and his step dad. He (maybe in his mid twenties) was obviously not very mechanically inclined, but his step dad seemed to know what was up. They looked at the clutch, handed me money, and left. Awesome.
Up until now, normal story right? Well, buckle up! About an hour later I got another FB message (with a picture) that they had installed the starter clutch successfully inside their kitchen, and the bike now turned over with the starter. Nice, I liked hearing that the part worked. They were pushing the bike outside to see if it would start. Then I heard nothing. The next morning I woke up to another FB message that now he needed a fuel pump. Ug. I knew this was going to be an issue because for whatever reason these fuel pumps pull 300-400 on ebay, and while I did have a fuel pump that would probably work for him, I had it listed on ebay for $350. I could also tell from my previous interactions that a $350 fuel pump was probably not in the cards for this guy. I told him I had one, but also that they bring 300-400 on ebay and I would sell him mine for 200 to skip the ebay nonsense. He sent me a pick of a cheapo amazon replacement fuel pump for who knows what that was $30 and said my price was too much but he only had 100. Ok, here comes the crap I thought.
So I took a risk, I asked him what the symptoms with his bike were. We quickly established that the fuel pump gets power with key on and does push fuel if the line is disconnected. Bike will start on ether. Not starting otherwise. Remember I said the step dad was pretty good? He had already established all of this. But remember the dad is the knowledgeable one and im working through the kid who doesn't really understand the systems. A phone call happens. There's a language gap a little bit because they are both pretty thick on Jamaican accents. Parts have different names. They're telling me the injectors are getting 'pulse' but I'm not sure if that means 12Vs, or a flashing noid light, or something in between. I tell them to come over and bring their fuel pump.
I'm literally typing out that I will sell him my fuel pump for $100 if he brings me his in trade as well when my email dings. The FP that I've had listed for weeks at $350 sold and was paid that exact moment. By someone else. Good thing I didn't hit enter!
These guys are already on their way over to my house, and they are both still sure the FP is just not hitting the right pressure or volume (but they haven't tested either to my knowledge). Crap.
When they arrive, I help them mock up a test setup. We hook up their fuel pump to one of the fuel rails I have laying around, and we give the pump 12v from a battery. When we hit the injector with 12v, we can all see the visible fuel spray. So at least for a few minutes I have them both convinced the fuel pump isn't the main problem. It's either in their injectors (odd for all 4 to die at the same time), or it's in their control or wiring (more likely). What's really odd is the bike still runs on ether, and according to my manual cam and crank and tip over and kickstand sensors are the only ones that would cause a 'no-start' but they all SHOULD cause both no spark AND no fuel. hmmm. I sent them home with 4 good injectors and a fuel rail. I told them they could bring it all back if it didn't work.
About 2 hours later, they are back here. They tried my injectors but they didn't fit (hmmmmm), but they were able to repeat the same bench test on theirs and prove the injectors were ok. So they narrowed it down to a signal issue. The crank sensor is in the same part of the case as the starter clutch, so they hypothesized that the crank sensor was gummed up or ruined by the failing starter clutch. Fair point, so I took the injectors back and gave them another crank senor to try. Remember I have all this stuff just sitting around, and all of this stuff is so cheap on ebay its almost not worth listing. I also sent them with a cam sensor and my workshop manual. Then I heard nothing.
Next morning I hear that they worked all night and still no dice. DANG! I'm pretty invested now. What could it be? Maybe the ECU? Wiring issue? But the diagrams show that the injectors and the fuel pump get power from the same circuit, and they are measuring 12v at the injectors. injector ground through the ECU. Looks pretty bad for the ECU at this point. I happen to have a spare ECU but the part number is not an exact match. I tell them to take it and try. They are getting a fault code that points to the intake air temp sensor. I give them one of those to try as well, as well as a tip over switch. None of that works.
Finally they came back last night to return all my stuff I had let them try. AND THEY HAD FIXED IT!!!! What was it?
Turns out, it was a faulty power commander. That neither of them ever mentioned to me they had on the bike (I would've said right away to remove that). Wait, you mean an aftermarket accessory that's sole purpose is to modify the fuel injector signal from the ECU was at fault when the engine was getting all the right signals except fuel injector signal? no way!
Anyway, when they returned all my stuff they also mentioned they wanted to buy a steering damper from me. The stock ones are like less than free on ebay so I told them $5. The dad handed me $20 and said thanks for all the help and for loaning him the parts and the manual.
There are good people out there folks. Even on facebook. Also I'm sure I'm going to hear from this guy again the next time his bike needs something... haha
