Fuel pressure gauge

[dern]

Can anyone recommend a fuel pressure gauge I can mount on a bike to check fuel pressure while riding. It's not a permanent requirement, just for diagnostics. Ideally will work for FI and carb'd. Thanks.

[Le_Fromage_Grande]

I don't think I've ever seen one, would an oil pressure gauge work?

[mangocrazy]

If it was on a car it would be a lot simpler, as you could use an OBD II diagnostic scanner tool. This gives you real-time engine fuel pressure readings, directly from the fuel pressure sensor. But on a bike, I suspect you would need to plumb in a dedicated fuel pressure gauge, with a takeoff from the delivery fuel line, which would be cumbersome and hard to make a neat job out of. Places like Demon Tweeks sell fuel pressure gauges, but I don't know how suitable they'd be for bikes.

[dern]

I've seen this sort of thing...

fpg.jpg (105.99 KiB) Viewed 464 times

...but I'm not sure if they can be used while riding. I suspect that they're not intended for this but as long as all the hoses were secured and you don't press the pressure release valve it would probably be ok... maybe.

[Le_Fromage_Grande]

I don't see why that wouldn't work, so long as everything is sealed you should be good, do you need to ride the bike, doesn't the pump always pump at the same pressure and any excess fuel returned to the tank with injection and with carbs the pump only pumps when the fuel level is low in the carbs (this is how old Yamahas work)

[mangocrazy]

doesn't the pump always pump at the same pressure

I suspect that's what he wants to check. Varying fuel pressure on FI can give rise to some odd faults, and if it drops below a certain value the ECU won't trigger the injectors to fire.

[dern]

doesn't the pump always pump at the same pressure

I suspect that's what he wants to check. Varying fuel pressure on FI can give rise to some odd faults, and if it drops below a certain value the ECU won't trigger the injectors to fire.

Exactly, I'm looking for reasons for an intermittent failure. Better to buy tools to diagnose than parts to try out.

[mangocrazy]

Is this on the RSV, by any chance? I know that a number of owners were getting intermittent failures with no obvious cause and it turned out to be the wiring to the in-tank fuel pump. To make it really devious it was the section that was encased in rubber (or potted, can't recall) and was part of the fuel pump assembly. It needed some serious tracking down.

[dern]

Is this on the RSV, by any chance? I know that a number of owners were getting intermittent failures with no obvious cause and it turned out to be the wiring to the in-tank fuel pump. To make it really devious it was the section that was encased in rubber (or potted, can't recall) and was part of the fuel pump assembly. It needed some serious tracking down.

That's the bike. Yikes, that sounds fun to find.

[mangocrazy]

I'd have a look on some of the 'Priller forums and start searching. Alternatively give Griff a ring at AP Workshops. He'll have seen it all before. And tell him Graham with the Falco and the LC sent you...

[Skub]

I'd have a look on some of the 'Priller forums and start searching. Alternatively give Griff a ring at AP Workshops. He'll have seen it all before. And tell him Graham with the Falco and the LC sent you...

I wish an outfit like this was close to me.

[mangocrazy]

I'd have a look on some of the 'Priller forums and start searching. Alternatively give Griff a ring at AP Workshops. He'll have seen it all before. And tell him Graham with the Falco and the LC sent you...

I wish an outfit like this was close to me.

Griff is a bit of a legend in Aprilia circles. When I lived in Stafford he was less than 30 miles away from me.

[dern]

I'm booked in to take the bike there next month but it's a couple of hours from me and they're not open at the weekends.