1990 FZR400 fuel pump running constantly

The fuel pump on my 1990 FZR400 is running constantly. STRONG too. I did crash it on it's right side a few weeks ago. Coincidence?

Advice?

 

I had my TZ fuel pump running constantly once after a rebuild. Turned it off once I discovered fuel pouring out the airbox all over the ground!

Oops, left the carb drain plug off...

 

Pull the carbs apart...probably some trash in a float needle seat.

 

yes, check this.

However, is it running at full tilt? If yes, then it seems like you might have something else going on, I'd suspect the pump is going flaky.

 

There is a fuel pump relay in the circuit that is supposed to shut the pump off after 30 continuous seconds. Check the relay first, then the pump. It is also supposed to shut off at a certain pressure, so then check the pump to make sure it is actually pumping. The FZR can run without the pump, just not a low fuel levels, especially if the diaphragm is messed up. Relay first, pump second.

 

Nope. Checked that.

 

Okay, that's not out of question. But, when I say the pump is running STRONG, I means it's never ran that hard and loud before. I've had stuck needles before and could hear the pump compensating for the lost fuel and it doesn't sound like that at all.

 

First on my list too. It's running at a sound and speed that it's never ran before. To me it's kinda like right before a lightbulb in a lamp will burn out, it get's REAL bright.

Just a hunch though.

 

Will do this first.:up:

 

Oh, and here's another damned thing....my right front caliper is leaking brake fluid. I'm guessing they're both crash related. FML.

 

fuel lever in the "on" position? dunno about the fzr but on my cbr if i leave the fuel "off" the pump will run constantly.

 

Is it pumping fuel or just spinning its wheels?

 

Thanks but, it's on.

 

It's pumping like a mofo. When I turned the key on today, I heard it priming like hell. I didn't think twice about it when I hit the start switch and the bike fired up INSTANTANEOUSLY! Then it idled on choke like a scalded dog.

 

How low is the fuel? Borderline reserve level by chance? And how long did you let the bike run?

 

i bet if you pulled the line off it's running, but not actually pumping. probably a bad diaphragm.

as for the leaky caliper - where's it leaking from? look close, check twice, that stuff is sneaky.

OH and in my experience, FZR 400's are the master of the coincidental, unrelated mechanical issue. Stuff that seems to be related, but is really totally random, just to add to the madness...........

 

Half tank. About ten minutes.

 

Make sure the hose isn't pinched. Pick the tank up and let it run. Also what Kenny said but then your carbs will look like mine. Filled the crankcase.

Also, just take the calipers apart and it means your O rings are leaking. It is from the heat of racing.

Beleive me, your hose it bent.... Ask me how I know. If not, check the relay.

 

Are you sure it's the calipers and not fork oil migrating down from a weeping seal?

 

I might have found something. Checking relays right now.