imnotvincent Posted August 10, 2021 Share Posted August 10, 2021 (edited) Need help diagnosing. Bike dies after starting. Need help. Bike info : Also has some sort of Intake, with Two UNI pod filters 2015 FZ07 about 30k miles (Purchased at 24k don’t know previous services) Rotella T6 for last 5k miles Full Yoshi Exhaust Pretty sure it’s been reflashed (has Hordpower sticker on the side of ECU) https://youtube.com/shorts/23ZJ1qQFnls?feature=share Video of bike starting then dieing So I got back from a ride last night, bike ran perfectly during the ride. Get home shut the bike off. Turn the bike back on and check engine light comes on, I wait a few minutes and it doesn’t go off. So I kill the bike and restart it, the check engine is now gone. I now have the problem of the bike not wanting to stay on. I have since changed the oil and oil filter. Siphoned the gas out and added new gas (92 octane) and added fuel system cleaner. Air filters were replaced very recently (50miles ago) and I’ve checked them, they aren’t clogged or anything like that. I’ve asked some of my friends and they have said to check spark plugs next. Wanted to get some opinions from more mechanically inclined people before I start taking stuff apart to get the spark plugs out. Attached is a video of the bike as it sits right now. It starts but dies after 30seconds. Any info or ideas on what could be causing this would be greatly appreciated. Thanks. Edit: I have since changed spark plugs and still have the same issue, now I noticed a clicking/sucking sound coming from under the tank area. Will upload video soon if the sound. Replacing the fuel pump will probably be next. Edit 2: https://youtube.com/shorts/IfEZn3yfS0s?feature=share The second time I start it I hold the revs. I have also since replaced the battery with a new one, checked all the fuses and glued my tip over sensor. Edit 3: I have checked o2 sensors and it’s fine. I got a throttle body sync tool, and I’m trying to sync the throttle bodies. After I connect the lines to the throttle body, the bike won’t start whatsoever. I reconnect the plug(on the brake lever side) and the line(on the clutch side) and it starts but eventually dies again. I think the lines that came with the tool are a little too big. I was thinking about just turning the throttle body adjustment screws like 1/4 turn at a time to see if anything changes. I have ordered new lines for the tool that should fit. Does it matter which side I adjust ? The clutch side seems to connect to a sensor or something. Any ideas are greatly appreciated. This is probably gonna be my last ditch effort before taking it to a dealer and paying 200/hr to diagnose it. Sorry for paragraphs of reading. Thanks if you’ve made it this far. Edited August 10, 2021 by imnotvincent Removed unnecessary info Link to comment Share on other sites More sharing options...
Triple Jim Posted August 10, 2021 Share Posted August 10, 2021 (edited) I'm not terribly experienced with fuel injection, but it seems like a failing fuel pump could cause this. Based on my experience with one of my cars, I'd probably put a pressure gauge on the fuel pump output using a Tee in the line, and see if the pressure falls when the sputtering starts. Note that this needs to be done in a safe way that doesn't result in fuel spraying all over the place, and I haven't thought about the specifics of how to do that. Edit: There are videos on how to test the fuel pump output pressure. YouTube has some, including one called "How To Check Motorcycle Fuel Pressure & Fuel Flow". Edited August 10, 2021 by Triple Jim Link to comment Share on other sites More sharing options...
imnotvincent Posted August 10, 2021 Author Share Posted August 10, 2021 4 minutes ago, Triple Jim said: I'm not terribly experienced with fuel injection, but it seems like a failing fuel pump could cause this. Based on my experience with one of my cars, I'd probably put a pressure gauge on the fuel pump output using a Tee in the line, and see if the pressure falls when the sputtering starts. Note that this needs to be done in a safe way that doesn't result in fuel spraying all over the place, and I haven't thought about the specifics of how to do that. Edit: There are videos on how to test the fuel pump output pressure. YouTube has some, including one called "How To Check Motorcycle Fuel Pressure & Fuel Flow". The only thing that doesn’t make sense if it were the fuel pump, is it idles perfectly fine for the first 30 seconds. I was thinking on cold starts the ECU runs on a closed loop, then once warm it runs open loop and gets info from sensors and such. Which explains why it runs fine for the first bit. Link to comment Share on other sites More sharing options...
Triple Jim Posted August 10, 2021 Share Posted August 10, 2021 3 minutes ago, imnotvincent said: The only thing that doesn’t make sense if it were the fuel pump, is it idles perfectly fine for the first 30 seconds. I was thinking on cold starts the ECU runs on a closed loop, then once warm it runs open loop and gets info from sensors and such. Which explains why it runs fine for the first bit. I'm not saying I'm sure it's the fuel pump, but it's not hard to check its output pressure. When I had one fail in one of my cars it would start and run for several minutes. Then as the pump got hot it would slow down and the engine would sputter and eventually stall. I checked and replaced several sensors before I put a pressure gauge on the fuel log and taped it to the outside of the windshield. Then I went for a drive and sure enough... Link to comment Share on other sites More sharing options...
AP996 Posted August 10, 2021 Share Posted August 10, 2021 Might be worth trying it with the fuel tank lid undone, maybe you have a breather blocked or nipped. Easy to check before you get in too deep. Link to comment Share on other sites More sharing options...
imnotvincent Posted August 10, 2021 Author Share Posted August 10, 2021 4 minutes ago, Triple Jim said: I'm not saying I'm sure it's the fuel pump, but it's not hard to check its output pressure. When I had one fail in one of my cars it would start and run for several minutes. Then as the pump got hot it would slow down and the engine would sputter and eventually stall. I checked and replaced several sensors before I put a pressure gauge on the fuel log and taped it to the outside of the windshield. Then I went for a drive and sure enough... Okay, do you mind finding a video on how you’d test the fuel pump and sending it. Thanks! Link to comment Share on other sites More sharing options...
imnotvincent Posted August 10, 2021 Author Share Posted August 10, 2021 1 minute ago, AP996 said: Might be worth trying it with the fuel tank lid undone, maybe you have a breather blocked or nipped. Easy to check before you get in too deep. Try starting the bike with the tank lid open ? I’ve done that already, or do you mean adjusting throttle body’s with it open ? Link to comment Share on other sites More sharing options...
Triple Jim Posted August 10, 2021 Share Posted August 10, 2021 4 minutes ago, imnotvincent said: Okay, do you mind finding a video on how you’d test the fuel pump and sending it. Thanks! I haven't looked in depth, but I gave you the title of one on YouTube above. (Working now.) Link to comment Share on other sites More sharing options...
stickshift Posted August 10, 2021 Share Posted August 10, 2021 If the check engine light on came on there should be a fault code also. Some info below on how to get a fault code to display on the dash. If this doesn't work I would take it to a dealer to get them to read the fault code. Link to comment Share on other sites More sharing options...
imnotvincent Posted August 11, 2021 Author Share Posted August 11, 2021 2 hours ago, stickshift said: If the check engine light on came on there should be a fault code also. Some info below on how to get a fault code to display on the dash. If this doesn't work I would take it to a dealer to get them to read the fault code. The check engine light came on, then back off after restarting it. I never got a chance to look at the fault code. 1 Link to comment Share on other sites More sharing options...
myfootisdumb Posted August 11, 2021 Share Posted August 11, 2021 do spark plugs got them shipped from amazon for $28. that was my initial reaction at idle it will be rough like this and will seem fine at higher rpm. Link to comment Share on other sites More sharing options...
imnotvincent Posted August 11, 2021 Author Share Posted August 11, 2021 1 hour ago, myfootisdumb said: do spark plugs got them shipped from amazon for $28. that was my initial reaction at idle it will be rough like this and will seem fine at higher rpm. Already did spark plugs. They weren’t bad but I replaced them anyways. Link to comment Share on other sites More sharing options...
stickshift Posted August 11, 2021 Share Posted August 11, 2021 8 hours ago, imnotvincent said: The check engine light came on, then back off after restarting it. I never got a chance to look at the fault code. Take it to a dealer, the fault code may be stored in the ECU Link to comment Share on other sites More sharing options...
ElGonzales Posted August 11, 2021 Share Posted August 11, 2021 The last two times somebody mentioned a dying engine after some seconds of unstable idle rpms and an engine check light without error code in the dash it was a faulty MAP sensor. 1 Link to comment Share on other sites More sharing options...
mossrider Posted August 12, 2021 Share Posted August 12, 2021 So if you replaced the spark plugs you probably lifted or removed the gas tank. Did you remember to reconnect the sensor at the right front of the fuel tank under the bodywork? Link to comment Share on other sites More sharing options...
imnotvincent Posted August 12, 2021 Author Share Posted August 12, 2021 2 hours ago, mossrider said: So if you replaced the spark plugs you probably lifted or removed the gas tank. Did you remember to reconnect the sensor at the right front of the fuel tank under the bodywork? Yes most of the bike is still taken apart. That sensor is plugged in. I’m trying to do a throttle body sync, but every time I connect gauges to it it just dies. I have the same sync tool as him. And did basically same steps as him. Link to comment Share on other sites More sharing options...
imnotvincent Posted August 12, 2021 Author Share Posted August 12, 2021 (edited) 7 hours ago, ElGonzales said: The last two times somebody mentioned a dying engine after some seconds of unstable idle rpms and an engine check light without error code in the dash it was a faulty MAP sensor. Where is this located at on the bike? Is there any way I can test it ? Also how would I know which model bike I have ? Obviously FZ07, but there’s words after it on partzilla. (For example, FZ07FCR etc…) Edited August 12, 2021 by imnotvincent Link to comment Share on other sites More sharing options...
Triple Jim Posted August 12, 2021 Share Posted August 12, 2021 Those letters just tell what color it is. If you check the parts listings I think they'll all be the same. Link to comment Share on other sites More sharing options...
shinyribs Posted August 12, 2021 Share Posted August 12, 2021 I haven't watched your videos yet. But DO NOT move the synch screws until you get the bike running again. That's not what made the bike stop running, and you don't want to be having to get an engine up and running again with the synch screws at random places. Link to comment Share on other sites More sharing options...
imnotvincent Posted August 13, 2021 Author Share Posted August 13, 2021 1 hour ago, shinyribs said: I haven't watched your videos yet. But DO NOT move the synch screws until you get the bike running again. That's not what made the bike stop running, and you don't want to be having to get an engine up and running again with the synch screws at random places. I’ve had a couple different people tell me it could be WAYYY out of sync but I’m not too sure. I’m not sure if the previous owner every synced it. I’ve ordered a MAP sensor hopefully it’s what’s faulty. Link to comment Share on other sites More sharing options...
Triple Jim Posted August 13, 2021 Share Posted August 13, 2021 They don't go out of sync much just from riding. If they need an adjustment it's only a small one. 3 Link to comment Share on other sites More sharing options...
imnotvincent Posted August 20, 2021 Author Share Posted August 20, 2021 On 8/11/2021 at 2:26 PM, ElGonzales said: The last two times somebody mentioned a dying engine after some seconds of unstable idle rpms and an engine check light without error code in the dash it was a faulty MAP sensor. It’s fixed! I replaced the map sensor and it rides like a dream now! Only thing is mine only had the check engine light once when it first happened. Then after that no check engine light or error codes. 1 Link to comment Share on other sites More sharing options...
ElGonzales Posted August 20, 2021 Share Posted August 20, 2021 (edited) Toss a coin to your witcher ! The descriptions of the error pattern vary slightly, but as long as we don't have a great Yamaha diagnostic tool, we sometimes have to guess a bit. It's also possible to check the sensor, some days ago I posted a sloppy YouTube Video how I did it. You have to give it a supply voltage at two pins of it's connector and measure it's output voltage at the third pin while there's a certain negative air pressure at the hose connector. Service manual says: 4.2V at 119.990 kPa - but I think testing through the whole pressure range the running engine produces is better. Put the measured values in a diagram and we should see a linear relationship between connected negative pressure and voltage output like in this example I've tested. But haven't tortured my original Yamaha sensor yet Edited August 20, 2021 by ElGonzales Link to comment Share on other sites More sharing options...
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