Fuel System Reassembly Problem?

[Mogan]

I just finished installing a bulkhead fitting and "hooray" no leaks so far. The fuel tank has been remounted in the rear and all connectors and hoses have been reattached.

BUT, the bike doesn't want to start. I put about 1/2 gallon of gas in the tank (what it had when I started the removal process) and it kicks over, fires, but doesn't stay running. Sounds like it's starved for fuel.

Any ideas on what may be wrong????

 

[ionbeam]

When you looked under the gas tank, did you see which hose got pinched?

 

[Mogan]

One thing that does seem odd is that the two hoses on the left side of the tank seem switched. I labeled them when I took everything apart, but they now seemed crossed. Could this account for the problem?

 

[ionbeam]

One thing that does seem odd is that the two hoses on the left side of the tank seem switched

One hose is the tank overflow, the other is tank vent which I believe has a check valve in it. They should be installed correctly but being swapped won't (shouldn't) matter to running. But, pinching the vent line will cause exactly your symptoms. So will pinching any of the hoses on the right side of the gas tank. The way the retaining bracket is set up on the right side it is easy to pinch the hoses.

Alan

 

[radman]

Does the pump cycle when key is switched on? I haven't added an aux tank, so my knowledge here is limited, but generally, look at what ya played with.

 

[Mogan]

Haven't been able to see any pinching...

 

[ionbeam]

It is tough to diagnose problems on-line. Holding the phone: Hello, doctor? What is this funny spot I got here?

In FI systems both the feed and return fuel lines need to be working. The fuel pump pressurizes the fuel line with more fuel than the injectors can use, this is the reason you have fuel pressure. The pressure regulator returns the unused gas back to the fuel tank.

Do you have good pressure? Do both the feed and return lines work? Ahem, does the fuel pickup reach the fuel? :der:

Check out this fine site and see if it offers any tips:

https://www.fjr1300.info/howto/bulkhead.html

Alan

 

[Mogan]

Thanks for the suggestions. NO JOY.

Took the tank off again, removed the fuel pump assembly, took it apart and reassembled everything. No change. :angry:

 

[FJReady]

Mogan,

When I recently did my TBS the bike conked out with very little tilting of the tank. It had maybe a gallon in it. Had to add a couple more gallons to get it to run with tank elevated. Perhaps your fuel level is just below the threshold it will run at? Is it possible the additional fuel lines you added consumed just enough of the half gallon or so of gas to starve your fuel pump? Just thinking.

FJReady

 

[Mogan]

FJReady-

A good thought, but that did occur to me too. I added more gas...about 1/3 of a tank and tried running it all the way down and in various tilt positions. No Joy! Although I added a bulkhead fitting and the related connector line, the aux tank is not yet connected so very little fuel was lost via that source.

Oddly, more fuel seems to be draining from the fuel line than when I first disconnected it. First time just a bit of fuel trickled out of the line. The second time it seemed to poor out a la gravity feed. I'm not sure what could account for this difference. Perhaps a vacuum problem? In any case, I've rechecked each line about 10 times and can't locate a problem. Urrggg!!!!!!!!!!

 

[Mogan]

Possible Clue?????

I dissassembled and reassembled everything including the fuel pump housing one last time--leaving gas in the tank. After reassembling I noticed that fuel seems to flow freely out of the fuel-in fitting on the fuel pump. I don't think this is normal.

I did a significant amount of electrical farkling while the tank was off. Don't know if I could have messed up something with the fuel injection system in the process.

Any other ideas? I'm stumped. :dribble:

 

[radman]

Start from scratch. Pull the plugs after a start attempt. Are they wet? Wet plugs don't spark. New plugs, disconnect fuel pump wire connector, start bike on fuel dumped in cylinders. When bike dies, reconnect and should be ready to go. You havent answered as to whether the pump starts up at key on. If not, check fuse. Check injection fuse under panel c-d. You played with wiring, you coulda popped one. Ditto ign fuse. If all this checks out, plugs are dry, fuses good, still no start, cycle pump several times with key on for 2 secs, off, Again. And again. You may have air in the fuel rail. Pulling and plugging the vac line on the fuel pressure valve (right side of rail) will crank fuel pressure to max with no vac signal present. Verify spark by connecting an old plug to one of the wires, ground the plug, turn over. Should be fat and blue. if you have compression, timing, spark and fuel IT MUST RUN!!!

 

[Mogan]

Radman-

LOTS of good ideas to try. Where EXACTLY is the fuel injection fuse? I see it's #7 on the wiring diagram, but I'm having trouble finding it. Panels A-D are removed and the tank is propped up Warchild method.

 

[radman]

FI fuse is below panel "D", behind the battery.

 

[Mogan]

Update-

Pulled remaing plastic off bike to make working on it easier. All fuses check out ok including fuel injection and ignition.

Fuel pump seems to work fine. Cycled the power switch a few times with fuel line disconnected at rail and lots of gas was being pumped. Reconnected everything and tried starting after multiple cycles. No joy.

I guess playing with the plugs is next or playing with the vacuum line.

 

[Mogan]

Pulled a plug and it's WET! Should I replace? Other?

Totally stuck.

I removed the plugs, disconnected the injectors and ran the engine to evacuate surplus fuel. Inserted new plugs, reconnected everything. Tried again. Exact same outcome.

Last call before the dealer emergency call. :wacko:

 

[SkooterG]

Mogan. Wow. Sorry, I have been so busy I just got to this thread.

I had the EXACT same thing happen to me after I installed my bulkhead fitting. Same symptoms.

After a lot of trial and error diagnosing, I fixed it, but I am not sure how.

This is what I think: Bubble in the fuel line, or some issue with the pump initially pressurizing the system. After trying a bunch of stuff to fix the problem, including getting into the diagnostic mode of the ECU, I eventually lifted the tank, disconnected the fuel line, and then turned on the ignition to verify that it was pumping fuel. Well, it was, gas came out of the line, so I guess that was not the problem, right?. (Of course I had a cup ready to catch the fuel) So I put everything back together, for the heck of it tried to start again.

Voila!!! Houston, we have ignition! :good:

Like I said, I tried a lot of different crap before this to no avail. So I am guessing there was a bubble, or some issue with getting fuel from the pump to the injectors, that I somehow fixed by shooting gas through the line.

So give that a try! I only hope its that simple for you, as it was for me. Good luck!

Greg

 

[radman]

You have to burn off the fuel remaining in the chambers for one. Disconnect the pump harness and with dry plugs try and start the bike. Most likely it will run for a few secs on the remaining fuel. Right now, you are adding fuel to an already flooded engine, and just wetting the plugs again.

 

[Mogan]

Thanks guys. I was fresh out of ideas. This a.m. I'll try Radman's latest suggestion first then do one more round of connecting/disconnecting everything.

fyi, I my last marathon of fiddling, I did run the fuel pump disconnected and it seemed to pump gas fine.

I still wonder if there isn't a vacuum problem somewhere. When I first took everything apart little/no gas flowed out of the system--just what was in the line at the time. Now, I disconnect the fuel line and it gravity feeds out of there like crazy. There was an old thread on another site about someone else with a asimilar problem. They ended up taking the bike in and he was told it was a kinked vacuum line. I don't know fo any on the tank bottom area other than the two vent hoses on the left. I can't remember which one is which but I've tried it both ways and I think they both just go to air--one for overflow and one for venting.

I'll keep ya posted! :angry:

P.S. For what it's worth, it's a great comfort to know there are great guys on this new forum. You're keeping me from hanging myself!