After I installed my Walbro pump, at start up I get this really weird vibrating cooing sound. It sounds similar to coolant boiling, but I coudl feel it through the floor board if I am sitting in the passenger side back seat. It goes away after a few seconds which is what baffles me.

Is it possible for the Walbro pump to be too long and bottoming out in the fuel tank resulting in the vibration? I installed everything correctly (drilling the bracket about 1/4" above, used new rubber isolator...etc).

Let me know before I go in there and hack off the nipple 1/4" to shorten it.

Thanks.

Kaiser

No it's just loud. Get used to it. :P

I like the sound personally. :thumbsup

Yo Kaiser,

I did not have that problem, but, when you turn your car on, the pump primes for like 1 second. This may be what you are hearing or it may be bubbles in your return line shaking the hardline.

Lates

James

I think it may be the bubbles (atleast it makes some sense). Eitherway I need to redo the whole fuel system back there. It looks like a rats nest.

Originally posted by eclipsekaiser
Is it possible for the Walbro pump to be too long and bottoming out in the fuel tank resulting in the vibration? I installed everything correctly (drilling the bracket about 1/4" above, used new rubber isolator...etc). Let me know before I go in there and hack off the nipple 1/4" to shorten it. Thanks. Kaiser

YES ITS TOO LONG! I dun told you nukka- you needs to hack off 1/4 from the brass hard line on the fuel sender, and from the rubber hose between the sender and the pump outlet.

Hacking the sender will NOT screw it up, you can still install the stock pump back in with a longer rubber hose. The hose clamp will hold without that extra 1/4" and nipple.

The Walbro 255 will hit the bottom of the fuel tank and vibrate unless you cut off that nipple. You may need to re-drill the bracket a little higher once you chop it.

EDIT- Be careful when taking the rubber hose off the walbro outlet. There is a metal nipple clamped on to the plastic pump that has a check valve built into it. It's weak, and the nipple and checkvalve can pop off if you pull the rubber line too roughly.

Nukka Please....

I got the biach to fit like OEM today by taking your advice. 1/4" off the brass sender, and 1/4" off the rubber hose. Fit like a glove.

Funny thing is that it is exactly the width of the factory spring clamp that was on there.

Otherwise the nipple on the Walbro came off as predicted. had to push it back on.

Thanks for everyone's replies.

I dont get what the issue is here? all i did was take the old pump out and i drilled another hole in the bracket like a 1/8 in up and remounted everything with the new walbro, no cutting hoses or anything and mine doesnt vibrate or show any issues or hints of problems??? fit like a glove.

i dunno what the problem is at al. i didnt drill, cut, and modify anything for my walbro install. you guys blow goat balls.

strange, the cooing sound is still there. It can not be the pump bottoming out on the tank as it fit the factory bracket.

It has to be air bubbles...

For grain & others- I'm pretty sure there's two different GS/GST walbro's. I don't feel like researching exactly what the differences are, but some of the fittings included with the pump and the overall length are different.

As far as the cooing- walbros do hum. Theyre supposed to. It should go away as soon as you give it a little gas. You were describing a vibrating sound, which they shouldnt do. If you had come to the meet I could have checked it out for you.
:bash

Nukka, I was at a OC car auction from 9-4, afterward just kicked it at my sisters in HB.

I'm fairly sure there is air trapped in there. I will drive it around for a bit to see if it will purge itself. I was planning on redoing the whole fuel system down there anyways.