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Discussion Starter · #1 ·
Okay here is, Saturday was riding, running good, stopped at restaurant, ate, came out, could not get it started. But battery was weak, I knew that, so I didn't get too much cranking out of it. But there was a hint that something was up due to the fact it would normally just hit right off. ( Like maybe a problem before jumping) But then tried jumping it, finally got it to start but had to hold throttle wide open to start, when it did start it was blowing smoke and running badly, and wouldn't run under 2000 rpms. Smelling gas Got it home, ( trailer), everything looks good, front plug was kinda grey'ish, not bad but lots of gas present. Back plug black'er, but not horrible, it IS getting bright spark, but it seems like it just fueling like crazy. When I got it started once it blew raw gas out both pipes, and is dripping black sooty gas out of exhaust connection at the bottom. Unplugged PC5 and plugged harness as stock, no change. FI light on when key is cycled but goes off and stays off. ( Key on but not running). Seems like it's over fueling like crazy. When I took the front plug out to use checking spark, it blew a LOT of gas out, was dripping off everywhere on front fender and fairing. Definitely more than normal it seemed. So, anybody got any ideas ? Regulator ? ECM?
I hadn't rode it in about two months. Last it ran fine, as it always had. 15,000 miles. 2002.
 

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replace fuel pressure regulator.

you can check this piece by lifting the tank, there will be a little "tophat" looking fitting threaded on the rear right of the throttle body.

unplug the vacuum hose and cycle the fuel pump.

If fuel comes out of the vacuum, your FPR needs to be replaced.
 
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Discussion Starter · #3 ·
Thanks for the reply. I actually have been thinking that too. "What would make it flood with too much fuel" I have been thinking regulator, that would do it stuck shut. I already looked and "watched" one on eBay ( same one as for a lot of ST1300's too) but I'm going to check the vacuum line tomorrow first. But Its narrowing down to that to me too.
 

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Discussion Starter · #4 ·
replace fuel pressure regulator.

you can check this piece by lifting the tank, there will be a little "tophat" looking fitting threaded on the rear right of the throttle body.

unplug the vacuum hose and cycle the fuel pump.

If fuel comes out of the vacuum, your FPR needs to be replaced.
That was it, vacume line was pouring fuel out. Changed out the regulator and it runs great. Also changed plugs and the oil. Rear plug was really black, due to fact the regulator vacume line goes to the back cylinder, that can be a good indicator your FPR is going south. As black as that plug was I think the diaphragm may have been leaking for a while maybe before it just blew out totally. Oil was over full and "gasy", it was a lot of fuel going in that motor. I even "Blue Flamed" some out the exhaust when it started, I assume left over fuel in the ex pipe, just held it at 5000 rpms and blew it thru. Was really cool looking actually for a couple of seconds. Thanks for the help.
 
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