Odd Issue

[74Nitro]

Well after almost six seasons of 100% trouble free riding on my tuned from new SW it finally has an issue.
After a great high mileage ride yesterday my SW quit when stopped at a roadway for no apparent reason.
Details:
- 65 miles since refuel
-1/2 tank of fuel on gage
- 6'c/43f
-ok snow conditions with scratchers down and BOP aux radiator fan running
-sled temp normal@ 170f
-6500 header tuned miles, closed loop, adjustable fpr, hurricane big fuel pump, fuel return over slipper, fuel pump direct power harness, two fuel tank vent lines
-could here fuel pump cycle before it restarted
-fuel pressure gage indicated normal key on pressure before restart

Unfortunately I wasn't data logging!

NO CODES

After a short wait the sled fired right up and ran normal for a couple miles then quit again and this repeated one more time until it got me home and in the shop. Definitely seemed fuel related to me.

I have reviewed the " Three gallons or less" running issues thread for some ideas.

I plan on systematically step by step perform the following to see if any one individually has an effect or cure:

- drain the tank and add only one gallon of fresh fuel and see if it runs or repeats
- replace the fuel pump relay with another sealed one I keep as a spare.
- bypass the aftermarket pump relay harness and go back to stock wiring connection
- check the fuel pickups and fuel pump hoses
- change out the fuel pump for one I have as a spare [Deatschwerks 9-201-1000 255 lph]

Hopefully that process will track down or at least eliminate the fuel system as a possible issue.

I guess I will pull out my trusty Yamacharged Attak for my next ride.

Have you ever checked your valve clearances?

 

[sideshowBob]

Have you ever checked your valve clearances?

I have not...yet...but it is towards the end of my list of possible causes and things to check after the fuel pump and then stator/pickup.
I know I have read that on Apexs the valve clearance tightening up can cause stalling and Idle issues but my SW symptoms were dissimilar and came on suddenly with no previous or now current running issues. But who knows....I will eventually get to the bottom of it.
Never say never

 

[jonlafon1]

My experience with crank sensor going out was, I noticed it started kind of funny like. Almost like a cough on start up. Only did it once and then I was back at cabin> Next morning nothing it would crank but no codes no run just cranked over. After reading this post, going with water in fuel. Or possibly some kind of electrical issue/short. Hope you got it Bob.

 

[Turboflash]

Have you ever checked your valve clearances?

Even if valve clearances were starting to be out of spec, that wouldn't cause sudden immediate engine shut down. In such a case, the engine would exhibit gradual runability issues like difficult cold start, perhaps gradual lack of power (boost down some), erratic idle, etc. Bob said his sled just shut off while he was sitting idling.
Water and gas don't ever mix. While riding, there was enough gas (mixed with water) to keep sled running satisfactorly. But once he stopped (gas no longer being mixed with water), immediate phase separation began quickly with water sinking to bottom of tank (right where fuel pump draws from). Happens immediately. Fuel pump begins drawing in water sending it to injectors. NFG.
Possible cures: pump out watered down gas and replace with fresh gas. Add isopropyl alcohol to absorb water.

 

[sideshowBob]

I have removed as much of the old fuel from the tank as I could . Fresh 91 octane fuel in the tank now with added isopropyl so any fuel issues should be eliminated. Long ride planned soon so I will know by the weekend.

 

[74Nitro]

Even if valve clearances were starting to be out of spec, that wouldn't cause sudden immediate engine shut down. In such a case, the engine would exhibit gradual runability issues like difficult cold start, perhaps gradual lack of power (boost down some), erratic idle, etc. Bob said his sled just shut off while he was sitting idling.
Water and gas don't ever mix. While riding, there was enough gas (mixed with water) to keep sled running satisfactorly. But once he stopped (gas no longer being mixed with water), immediate phase separation began quickly with water sinking to bottom of tank (right where fuel pump draws from). Happens immediately. Fuel pump begins drawing in water sending it to injectors. NFG.
Possible cures: pump out watered down gas and replace with fresh gas. Add isopropyl alcohol to absorb water.

I've had a few atv's come in over the years where they would run fine except for when you came to a stop they would stall and almost immediately start back up. The problem turned out to be the exhaust side clearance was too tight. Once some of the heat came out of the valve it would start back up and idle fine. It had to be driven with load in order to get the valve hotter, which causes less or no clearance.
These were carbed engines, so may not react entirely similar.
Agree on the fuel.

 

[sideshowBob]

I've had a few atv's come in over the years where they would run fine except for when you came to a stop they would stall and almost immediately start back up. The problem turned out to be the exhaust side clearance was too tight. Once some of the heat came out of the valve it would start back up and idle fine. It had to be driven with load in order to get the valve hotter, which causes less or no clearance.
These were carbed engines, so may not react entirely similar.
Agree on the fuel.

I had a XR350 in the 1980s that was doing that exact same thing, I initially thought it was the CDI but a valve adjustment is what cured the problem. The big difference there was it was a single cylinder so it couldn't run with any valve slightly open The odds of my SW having a valve simultaneously hang open, due to heat expansion, in every cylinder I think would be unlikely....but you never know

 

[cannondale27]

Pull the fuel pump and check the wires on the underside of where they go through the plastic cover. I have heard of them breaking

Yup mine. Pump moves slightly. Only thing holding it is the sock and the wires at least mine should not have so much bare wire which is brittle from soldering showing. I resoldered and used shrink tubing over wire and receptacle.

 

[fatchance]

I drilled out that wiring and replaced it with 12 gauge wire with the Walbro connector up through the inspection plate. No weak points to worry about. Do not use JB weld 2 part epoxy to seal. Ask me how i know! Use a good 2 part resin ultimately UV activated for a rapid cure.

 

[cannondale27]

Another good tip related is instead of using the Flex tubing to pump use FI rated rubber hose and cut it to exact length needed to hold pump all the way down in reservoir. Murdered here suggested that and I thought it was a great idea to keep pump from moving up and down. Especially since some of the performance pumps the sock is smaller than stock and allows more movement.

 

[GlennM]

Check the fuel pump plugs. Happened to me in a field where it just quit one day riding alone in the middle of no where. The next day while it ran fine, went into a pit stop, shut it off and It would not start at all. I knew It had no fuel pressure or fuel pump, suspected it was a relay, warmed and swapped them out still no fuel pump. Friend came with the trailer and got me home. We took the seat off and found the fuel pump plug in completely fried. Cut off the stock plug ins, replaced with HD plug ins and been fine since.

Can you show your HD plug, any link?

 

[sideshowBob]

We got a bonus 6 to 10" late March snowfall and I did a 150 mile+++ ride today ....and I am to happy to report my SW performed flawlessly though out the entire ride.
I am still skeptical but maybe my issue was simply water in the fuel, I guess I tend to over complicate running issues when it basically falls back to the simplest solutions.
Anyway...so far so good....