Weird gas gauge with Walbro pump?

Post by **Legacy777** » Thu May 11, 2006 3:26 am

Just curious if anyone else that has installed the walbro pump has a fluctuation/weird gas gauge when the tank get's low...

The only thing I can think of is that the higher flow of the walbro is causing the jet pump to suck down the other side quicker.

I had some weird issues with the 93 float and stuff....and put the older 90 float system back in, and that helped for the most part, however if I run it down to a 1/4 tank or so I get the weirdness described above. If I make a left turn, the gauge goes up......so that would sort of confirm the theory.

Splinter · Post by **Splinter** » Thu May 11, 2006 3:32 am

Ive got weirdness with mine...

I figured I must have bent the armature when I reinstalled the assembly.

free5ty1e · Post by **free5ty1e** » Thu May 11, 2006 3:45 pm

Well, I have noticed that when the gas is low the level does seem susceptible to little fluctuations with the Walbro. Didn't used to do that with the stock pump. I was super careful to not bend any of that assembly when removing or reinstalling it, so I guess it must have to do with the higher flow moving fuel faster.

Post by **Legacy777** » Thu May 11, 2006 6:45 pm

Yeah....that's the only thing I can think of too.

If I remember correctly, the jet pump is driven off of the fuel returning from the regulator. Since the supply flow is greater, the return flow should be greater as well.

free5ty1e · Post by **free5ty1e** » Thu May 11, 2006 8:59 pm

Yeah, you know, the computer (or the conditioning circuit for the fuel level sensor, whichever handles it) is probably designed to compensate for the oscillations associated with the flow of the factory pump and make the gauge needle relatively stable. I can see how more flow would probably result in some oscillations that wouldn't be filtered out of the gauge reading.

Great pump though.

Splinter · Post by **Splinter** » Thu May 11, 2006 9:02 pm

Are you running the stock regulator?

Post by **Legacy777** » Thu May 11, 2006 10:26 pm

you mean fuel pressure regulator?

yes.

Post by **Legacy777** » Fri May 12, 2006 6:39 pm

Well....I think I have other issues with the gas gauge.....yesterday it was going all over the place. It was down around E, then went up to half, and then up to F again...and in between.

BAC5.2 · Post by **BAC5.2** » Fri May 12, 2006 7:51 pm

My gauge works fine.

The fuel gauge is controlled solely by the float in the tank, right? Maybe when you guys removed the pump rig, you loosened it up so the float bounces around a bit?

I also used the stock fuel pump sock, instead of the Walbro one. I was advised to do this by the WRX guys.

Kelly · Post by **Kelly** » Sat May 13, 2006 3:15 am

Never had any issues with mine. Used the Walbro sock too.

Post by **Legacy777** » Sat May 13, 2006 4:46 am

The float is not bouncing around.....the metal wire that attaches the float to the sender is pretty flexible.

I think I've either got some wiring issues, or possibly crud on the contacts.....however I just swapped the pump assembly a few months ago, and the contacts were fine.

Phill, why'd the wrx guys say to use the stock sock?

free5ty1e · Post by **free5ty1e** » Sat May 13, 2006 4:06 pm

The stock sock was filthy and did not fit right. Why would you use that when the kit comes with a nice new properly-fitting sock?

BAC5.2 · Post by **BAC5.2** » Sat May 13, 2006 6:47 pm

My stock sock was in fine condition and it fit just right.

Plus, since it is OEM, it filters to OEM spec.

Post by **Legacy777** » Sat May 13, 2006 7:17 pm

But you no longer have an OEM pump.

All those socks do is screen the chunks from getting into the pump.

BAC5.2 · Post by **BAC5.2** » Sat May 13, 2006 9:01 pm

So then it doesn't really matter which sock is used.

It's been working great for almost 20,000 miles, so I'm not complainin.

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Weird gas gauge with Walbro pump?

Weird gas gauge with Walbro pump?