Fuel Supply Problem... Low Flow - The Hull Truth

timo14 · 08-15-2007, 11:55 AM

I'm having a problem with my fuel flow. My alarm keeps going off when I'm at WOT or when taking off in rough seas. I had this problem once and found that my 3/8" line was kinking where it comes off the transom and loops into the outboard. I re-ran a new line and this solved the problem... for a while. The new line doesn't seem to be kinking at the same location as the old line. I recently added a Flo-Scan, and now the problem seems to be popping up again. Not all the time though. By the way, my Flo-Scan is off by 238%... it tells me I've burned 16 gallons, but it takes 38.1 to re-fill the tank. I've yet to troubleshoot it, but I'm wondering if it could be causing my restriction. Seems to make sense, maybe the wheel in the sensor isn't spinning as fast as the fuel is flowing. This would cause my low fuel consumption reading... and be restricting flow.

I just replaced the in-line fuel filter that is on the engine, and my Racor is new this season... maybe 20 hours max.

Not sure if I'm really asking a question, or just venting frustration. So many variables... anyone have a similar problem or any advice on where to start troubleshooting? I'm more concerned with fixing the fuel flow problem... having the flo-scan read properly is secondary. I'm afraid that if my fuel supply is low, I may be damaging my engine... even if just cruising.

Thanks, Tim

Bailey Boat · 08-15-2007, 12:07 PM

Disconnect the Flo Scan and see if the problem goes away...If it does then it must be the Flo Scan...... If not, then look elsewhere....

MrRobalo · 08-15-2007, 01:05 PM

Check your pickup at the tank. There should be a screen in the tude and a antisyphen valve in the elbo. Remove both of these as you are running with a waterseporator and you can add a fuel shutoff if it makes you feel better. I did.
The flow scan has a dial on the back that might need to be adjusted. I did ours and on a trip we took on 252 gal and the gauge showed 253. I can live with that.
Good luck .

timo14 · 09-18-2007, 05:30 PM

Well, I've been fiddling around with the fuel system. I removed the flo-scan... the problem has not gone away, but it is not as frequent. When I installed th Flo-Scan, i had to add about 2' of fuel line in a loop to make up for an elevation change. I cant see 2' of hose causing that much more friction.

I'm thinking that maybe I'll take out the fuel filter that is mounted to the engine. I still would have the Racor. Anyone see any problems with doing that? I haven't gotten around to checking the pickup tube. I'll try to take a look at that this weekend.

MrRobalo · 09-18-2007, 06:30 PM

Have you checked the pick-up tube for a screen (remove it)?????
Also have you checked to see if you have a antisyphen valve in the fuel elbo on the tank (remove it too)????
Hope this helps . Also call flow scan they were very helpfull.

mymojo · 09-18-2007, 06:34 PM

Definately look at replacing the anti siphon valve-quick and cheap fix for many fuel restriction problems.

Curmudgeon · 09-19-2007, 12:27 AM

Hook up a good portable tank directly to the engine and see what happens. If the problem persists, the problem is inside the engine. If the problem goes away, hook up the portable to the Racor and see. If the problem persists, change the fuel line and bulb. If the problem goes away, change out the plumbing from the Racor to the tank.

On a side note, check with your servicing dealer to determine if your engine fuel pump can support the length of line you have, the Racor, and the fuel flow transducer. Not all can, particularly when high flow rates are required ...