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Discussion Starter #1 (Edited)
I have a prob that is beggining to wear me down now, any input gratefully received. Here is a list of how the prob started and also of things done and tried to resolve it...
Very similar to engine cut out prob a lot of people have experienced. Cruising along and suddenly without warning revs start to drop right down and there is no throttle response, didnt note rpm or speed.Turned off highway just as engine died altogether, but electrics still on.whilst coasting i pulled clutch in and bumped engine back to life, carried on riding normally(not rough) and headed home, a mile from home same thing happens but i wasnt going fast enough to bump it again so i pulled in, now it wont start, no fuel pump priming noise, spins over but wont fire up.
Got it trailered back home, next day i went through all wiring loom, checked all connections, fuel dry breaks, did all diagnostic checks, all checked well, hooked battery directly to fuel pump and it pumped fuel through fine.checked no hoses were kinked or wires nipped. Plenty of fuel is in tank.Checked lean angle sensor, seems fine. My decompression solenoid is buggered but has been for a good while and that wouldnt stop bike from starting.
Next day i put new spark plugs in, re checked dry breaks, and tried starting it, this time i can hear the fuel pump go through its prime cycle, but because i had left battery tender off for 2 days the alarm system(data-tool) had more or less weakened battery too much for me to keep trying to start it(i knew it wanted to start as it was trying and fuel pump cycle was audible) so i hooked it up to car battery and it fired up straight away, so alls well i think, will take it for a good ride out tomorrow to check wether engine dies again.
Next afternoon i get ready to go out and check it,wont start again, no priming cycle heard, spins but wont fire. Drastic measures needed i think, so i take off alarm system totally and re-solder wires back to eliminate possibilty of alarm playing havoc with electrics, i did the 'perfect install' of PC3 to eliminate the nasty crimp splice on TPS wire.Hook it back up to car battery(to give it a bit of a chance) and still no start and still cant hear fuel pump(battery is only 2 months old by the way but seems to drain quickly after 4 or 5 days if not on tender).
Now i may be wrong but i think there are only 4 reasons bike wouldnt start-1/ knackered CPS
2/defective LAS
3/defective side stand switch
4/knackered fuel pump/relay
As i have done diag checks and none of these showed faults and also bike did start once before, i cant see it being any of these.
What would stop fuel pump priming sometimes and not other times, i cant help but think its something to do with the fuel system but cant pin it down. Sorry for the long explanation but need to show i am actually trying to do something about it. Cheers.:confused:
Forgot to say bike is an 05 with 36k on clock, has PC3 (perfect install), was told that TPS and CPS recalls were done but im unsure of this(has been running fine though)
 

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Just my .02 here. Could it be the fuel pump relay or maybe even the pump itself? You said the pump pumped fuel when hooked directly to the battery, but did it have any pressure or was it just an open ended hose you used? Maybe someone will chime in here as I can't remember what the fuel pressure should be.
 

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Discussion Starter #3
Just my .02 here. Could it be the fuel pump relay or maybe even the pump itself? You said the pump pumped fuel when hooked directly to the battery, but did it have any pressure or was it just an open ended hose you used? Maybe someone will chime in here as I can't remember what the fuel pressure should be.
This is what im thinking too, it was an open ended fuel line so wouldnt show any pressure would it ? , as for the fuel relay i did the diagnostic check on it and it said it was fine, but i guess the diag checks maybe shouldnt be totally trusted.I dont have the neccesary equipment for pressure testing, and im not technically minded enough to devise something for it, guess i will have to try get some mech head to come round and look for me, cheers for the input.:)
 

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Probably not helpful, but mine died on the road once and it took me forever to figure out I had somehow hit the kill switch as a I was riding along. Also had the clutch cable pop out of the case linkage while riding. Couldn't down shift or get to N so once I was going slow enough it killed. Didn't want to start for a bit after I got the cable back in. Not sure what was up with that. I assume you've gone thru all the fuses.
 

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Probably not helpful, but mine died on the road once and it took me forever to figure out I had somehow hit the kill switch as a I was riding along. Also had the clutch cable pop out of the case linkage while riding. Couldn't down shift or get to N so once I was going slow enough it killed. Didn't want to start for a bit after I got the cable back in. Not sure what was up with that. I assume you've gone thru all the fuses.
Good idea Loren....Check all the Kill switch wires and block connectors. Also check and clean the brass tab inside the kill switch, but be very careful building it back the right way..The fuel pump doesn't prime with the key "ON" and the kill switch at "OFF".

Gav.
 

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My .02 on your starting problem follows:
If the engine turns over with the starter PB then there isn't an issue with the kill switch or any of the pre-start interlocks such as the neutral sw, kickstand etc.

The issue is with the FI sys relay, Item 9 in the hosted diagram here:

If you don't hear the fuel pump prime when the key is turned on then you need to check the circuit for the FI relay.
___________________________

NOTE: YFSM pg 6-10 Verifying sensors & actuators - Item 1 states to disconnect the fuel pump coupler. I've run the actuator Diag code 50 with this connected using the kill switch in the past as well as disconnected.
  • pg 6-16 Diag code 50
 

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The FI relay coil Blue/Red (-) receives a signal from the ECU. If the LAS was not operating properly there will be no signal at PIN 32 of ECU to operate relay coil. Check the LAS connector and wiring.
  • The LAS can be checked in the Diagnostic mode under sensors
The opposite side of the relay coil Blk/Red (+) feeds the ignition coils etc and must be working else the engine wouldn't turn over via kill sw.
  • ADDED: the exception here is if the tracing or internal wiring was NG inside the Relay unit because of a short circuit
So what remains is the contact of Item 11 feed by Brn/Blk (+) from fuse 71 and any of the interconnecting wiring to the Fuel Pump from relay contact of Item 11 Red/Blue.
 

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Based on my understanding of the FI start circuit the Blue/Red (-) signal from Pin 32 of the ECU is intermittent or momentary to prime the FI manifold. Once the starter PB is operated the ECU recognizes the CPS signal that the motor is started and the signal at Pin 32 is continuous unless the bike overturns or the ignition or kill sw is operated.

An idiot light or instrument bulb across the fuel pump Red/Blue & Grnd will confirm the above.

Once again starting from the top, IF THE ENGINE TURNS OVER WITH THE STARTER PB AND YOU DON'T HEAR THE FI PRIME WHEN KEY IS 1ST TURNED ON THEN I FEEL MY APPROACH WOULD BE VIABLE TO SOLVE THE ISSUE.

I can appreciate that the Hands-On to trouble shoot the FI relay is not maintenance friendly as i've been down this road ... good luck
 

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Once again starting from the top, IF THE ENGINE TURNS OVER WITH THE STARTER PB AND YOU DON'T HEAR THE FI PRIME WHEN KEY IS 1ST TURNED ON THEN I FEEL MY APPROACH WOULD BE VIABLE TO SOLVE THE ISSUE.... good luck
Good info there Alan, have you a part number for the FI relay ?, there are a few on the fiche which just mention "relay". Like you say, the LAS could be the problem, wiring or internally.

Gav.
 

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Good info there Alan, have you a part number for the FI relay ?, there are a few on the fiche which just mention "relay". Like you say, the LAS could be the problem, wiring or internally.

Gav.
Reading through what Alan has posted plus looking back through some of his other links a faulty Lean Angle Sensor would give you the symptoms you've described.
When it's triggered it cuts the fuel delivery, the bike will still crank but not start.
Would also check this in conjuction with your kill switch.
The diagnostic check may not show it as faulty if it's working when you do the check.

Can anyone post a picture of where the sensor is on the bike?


Don't worry, I've found it. Might take mine out and check/clean the connections now I've found it. (it's behind the left side horn for those that have one)




Nick
 

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Don't worry, I've found it. Might take mine out and check/clean the connections now I've found it. (it's behind the left side horn for those that have one)Nick
I took mine apart when I was sorting the problem I had, end of 2009. Just unplug "the awkward to get to" sensor Nick, clean and seal the block connector with silicone or marine grease, don't take it apart, there's not much in there, a printed circuit and a plastic 1/2 moon.

Gav.
 

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I took mine apart when I was sorting the problem I had, end of 2009. Just unplug "the awkward to get to" sensor Nick, clean and seal the block connector with silicone or marine grease, don't take it apart, there's not much in there, a printed circuit and a plastic 1/2 moon.

Gav.

All done :)
 

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Nick & Gav ... my time today is committed to a customer so i can't answer your questions other than to say that the Relay in question is difficult to identify.

There is the head light relay & the FI relay unit and they appear on the parts fiche as a relay only so you'll need to use the YFSM (Yamaha Factory Service Manual) to identify their correct position.
If you check my Homepage flickr photos of the battery box folder i think you'll see some of the devices in question, maybe? for sure the T/S Denso & headlight relay!

Nick, i'm not aware of the LAS ever preventing a member's bike from starting up. It has always been a high speed intermittent issue at 80-90mph etc so if that's what you guys read into what i've posted i apologize for misleading you. Of course anything is possible and there is always a 1st but i've not heard of it.

The following statement is Boiler Plate: If the the engine turns over via the starter PB then the Kill SW is NOT an issue and ALL the prestart interlocks are working properly as stated earlier so move on....

I would use the on board diagnostics to trouble shoot and also carefully inspect the FI relay wiring at the buried Hitachi connector etc. This will require getting into the trenches with hand to hand troubleshooting with a DVOM or equiv... good luck
 

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Nick & Gav
Nick, i'm not aware of the LAS ever preventing a member's bike from starting up. It has always been a high speed intermittent issue at 80-90mph etc so if that's what you guys read into what i've posted i apologize for misleading you. Of course anything is possible and there is always a 1st but i've not heard of it.
No need for apologies Alan, it's worth checking everything before buying unnecessarily. If we didn't have one of the most technically advanced cruisers on the market, there would be less need for this forum. A lot of these problematic discoveries on this Warrior forum even baffle the best Yamaha dealership technicians...Believe me, I know....;)

Gav.
 

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Discussion Starter #17
Thanks for all that info, going to try and get to bottom of it now, very demoralising is this !! even heard myself thinking 'sod it , gonna sell it and go back to carb 4 stroke', thats how it gets ya !!!, ridiculous.
 

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I would start with the LAS as that would be the easiest piece.
 

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Wow!!

Props to Alan and Gav and others who contributed to this thread.

If I ever have that kind of weird problem I'll now know to look to the Lean Angle Sensor (LAS... took me a bit to realize the acronym! ;-) ) ****, I might even take mine out, dis-assemble, clean and seal it now before it gives me problems!!

Thanks a million guys for the heads-up!
 

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Thanks for all that info, going to try and get to bottom of it now, very demoralising is this !! even heard myself thinking 'sod it , gonna sell it and go back to carb 4 stroke', thats how it gets ya !!!, ridiculous.

Don't give up. It will be worth it in the end, and you'll have learnt so much about your bike.



Nick
 
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