Fuel pressure question

[jermzfree]

So I drove my turbo bike in rush hour traffic for the first time, no overheating issues so far, but the fuel pressure gauge dropped 8 psi over the course of 45 minutes sitting in traffic. I heard the liquid filled analog gauges can flucuate with external temp changes. My gauge is a glow shift digital series. The pump is a Walbro with 700 miles use. Little afraid to boost it when it is reading that low, but not sure if it is just my cheepo gauge that is off. Any advice appreciated!

 

[E Zurcher]

Dropped 8 PSI or dropped to 8 psi?

 

[jermzfree]

Dropped 8 to 34 psi.

 

[E Zurcher]

From what little I know it should maintain regardless. Check out your fuel pressure regulator first. Check filters also. Wouldn't get on it until you have it worked out.

 

[jermzfree]

The Begi regulator has a new rebuild kit, and was done in house so I have full faith in it. I took it out and rode it today with no issues, under boost the pressure rises nicely. I insulated the fuel pump in heat wrap and will see if that has an effect on the problem. If it happens again Im going to hook up a fuel pressure tester and see if the gauge reading is off.

 

[arthur39]

I have had similar issues with the glow shift gauges, I do not think it is the gauge itself, but the voltage drop that happens when the bike heats up. Specially when the fans are on. The pressure drop you are seeing on the gauge most likely is from the voltage drop. I now run an analog gauge inline to my FPR as well, I rely on that when adjusting pressure at idle. The glow shift gauge I depend on when the tank is down. It reads a bit higher in pressure then the analog. It still is a tool for me to know if anything is out of whack with fuel pressure when cruising or in boost. A/f gauge is important as well if you don't have one I would recommend it. if pressure is down a/f should be lean, then you would know you have a problem. I would consider an analog gauge inline or on the rail as well. Can't hurt. Definately put my money on voltage drop to the digital gauge when the bike is hot. good luck

 

[isiahstites]

Buy a good gauge, it's alarming you of anything potentially bad with the fuel pressure. Wouldn't you be completely pissed if the bike went lean under boost and you never saw it because of a cheap ass gauge.

Good gauges are not much, engine rebuilds are.

 

[GIXERHP]

What was the Airfuel at???

 

[jermzfree]

What was the Airfuel at???

A/F did not change. Im thinking it was the gauge. I have had issues with my other glowshift gauges. The oil pressure gauge is not accurate, the digital boost gauge never worked out of the box, A/F is not bad but a little off even after calibrating it. If it turns out to be the fuel pressure gauge im going to wish I was born with an extra arm so I could give them 3 thumbs down!

 

[GIXERHP]

If the Air fuel did not change its fine, ithe the AF changed then there is a problem!

A/F did not change. Im thinking it was the gauge. I have had issues with my other glowshift gauges. The oil pressure gauge is not accurate, the digital boost gauge never worked out of the box, A/F is not bad but a little off even after calibrating it. If it turns out to be the fuel pressure gauge im going to wish I was born with an extra arm so I could give them 3 thumbs down!

 

[OZZYBUSA]

Buy a good gauge, it's alarming you of anything potentially bad with the fuel pressure. Wouldn't you be completely pissed if the bike went lean under boost and you never saw it because of a cheap ass gauge.

Good gauges are not much, engine rebuilds are.

That's so true .... buying an excellent gauge from the start will limit a lot of potential problems down the track....