Time To Pull The Pump (again)

When last I looked at it, I had just pulled the upper tank sending unit, found a broken wire and very carefully mended it. Then I tested it and found that I was getting the proper range of values through the range of the float arm. I reassembled it all, filled the tank and got full bars. The tank is down past half and I still get flashing fuel gauge with it showing full bars. To be honest I am a little disappointed. I figure I am going to need to buy a used fuel pump unit off ebay so that I can get the factory thermistor which I think is the cause of my flashing issue..

I am also still chasing a FI code #9. I took a break to replace the brake fluid but I am sure I will have to get into the throttle bodies to make any more head way there.
 
Big_Jim59 said:
When last I looked at it, I had just pulled the upper tank sending unit, found a broken wire and very carefully mended it. Then I tested it and found that I was getting the proper range of values through the range of the float arm. I reassembled it all, filled the tank and got full bars. The tank is down past half and I still get flashing fuel gauge with it showing full bars. To be honest I am a little disappointed. I figure I am going to need to buy a used fuel pump unit off ebay so that I can get the factory thermistor which I think is the cause of my flashing issue..

I am also still chasing a FI code #9. I took a break to replace the brake fluid but I am sure I will have to get into the throttle bodies to make any more head way there.
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FI Code 9 >>>> Goo in the 5 way feed to the MAP Sensor | ST1300 Related

Got the ST1300 out today for a startup and run up to operating temp in the driveway. Bike is 10 years old now and just shy of 40k. It started right up but immediately had running issues. Ran rough,died a couple of times and FI Light came on and would not go off. Tried a couple of restarts...
www.st-owners.com www.st-owners.com
 
I did read that article and that was my next stop on this journey. To get there I have to pull the air cleaner and get down to the throttle bodies and I just haven't had the heart to do it yet. I have had the bike scattered all over the garage for the better half of a week and I wanted to make sure it got back together before launching into another project.
 
Catmandu2 said:
But I will let a bottle of Seafoam do its thing, for a tankful first.
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I didn't get much results from the Seafoam,,,, and am now running a tank through with the new Gumout additive (with P.E.A.). In the meantime,,, I came across a couple of articles outside of this forum that are relevant to the problem. So in the interest of keeping info in one place,,, I am posting the links here,,, as they are very instructive. I am still searching for my root cause,,, but the wire crimps that Jim mentioned,, and the articles describe too,,, could wind up being my issue. Only time will tell,,, cheers,,, CAt'


 
Andrew Shadow said:
The only thing that I will add to that is with older or neglected ST1300's there have been a couple of failures of the terminal block on the top of the lower tank where the exterior wires connect to. The exterior of that block looks fine but it was found that there is either no connection or a bad connection between the exterior and the interior portions of that block. This resulted in poor, intermittent, or no continuity between the exterior wires and the interior wires. If you open it up again you might give that a good going over.
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I suggested checking that back in post # 16. This failure has been reported on this site before, so it is worth having a look.
 
Andrew Shadow said:
I suggested checking that back in post # 16. This failure has been reported on this site before, so it is worth having a look.
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Yes,,, I read all of this thread and several other threads as well, on this forum and elsewhere. I did refer to Big Jim's experiences in earlier posts. Although the solvents have intermittently revived the mileage calculator,,, (8) full bars are displayed on the level indicator (sometimes flashing and sometimes not), regardless of the quantity of fuel in the upper tank. If nothing changes after this upper tank is spent,,, I will pull the upper tank, clean the sender, and check the connections. Thanks for your earlier posts on these issues, Andrew,,, they are very helpful. cheers,, CAt'
 
So after a couple of rounds of chemo-cleaning, with Seafoam and Gumout,,, no success. Last night, I dug in and pulled the upper tanks sending unit out. No visual problems detected,, and the soldered points were tight,,, so out comes the magic erasers !! Put it all back together by midnight,, and tested it out today. So far,,, works like a charm. And I have enough eraser/s left to last me about 1000 years,,,, lol,,, CAt'

oh,, the sender did seem to have more consistant resistance readings after the eraser cleaning. And,, at no point did I see any residue on the unit or the eraser.
 

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The fuel leaves a varnish like coating that you often won't be able to see.
Glad it worked for you.
Much cheaper than all the Sea Foam and Gumout :rofl1:
 
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