Glacier Diesel Walbro pump low pressure.

[JBallou]

Have had a GFS392 system on my truck for a couple of years, worked great until I think recently. Have the 2 mic kit after the OEM 7 mic canister. Have a electric fuel pressure sensor running to my Quadzilla gauge. Sensor is at the CP3 pump. Picking up only 12-15 at idle and under load empty I can pull it down to 1-4 psi. Filters are all new, 14. 5v at the pump. No odd noises at the pump.



The wierd part is that I can pinch off the return and get 27psi at idle. Only did it for a 10 seconds, didn't want to pop a lid.



I have no drivability issues other than watching the numbers get smaller with more load.



Do I have a failing pump? or a bypass valve problem? Never have adjusted the valve.



Have a call in to GDP, but no return call, I know they don't have the kit any longer.

 

[JJPage]

Really, Richard is no longer selling the Walbros? I had hoped to pick up a spare pump(insurance). I will have to give him a call.

 

[BMeier]

I know another member that had the same system and it had failed on him all together, he said his would pull down to 1 psi under load when it was working. He now switched to a FASS pump. I have heard of others that had problems with the Walbro pump also.

 

[MickeyMiller]

I've had the Glacier 392 w 2mu filter kit on for 20K and happy with it so far. Richard previously said Glacier stopped carrying the Walbro pump because Walbro required Glacier to carry the entire Walbro line. I picked up a spare 392 off e-bay for $80... I'm sure I can swap it out in 10 minutes on the side of the road, if I have to!

 

[JBallou]

Lotsa banter, but no thoughts or suggestions?

 

[AH64ID]

My guess is the bypass valve is faulty.

 

[CumminsBu]

My guess is the bypass valve is faulty.

That's my guess also.

 

[JBallou]

Thanks I will give GDP another call.

 

[JBallou]

Just got off the phone with them. He thinks that the pump is dieing, being that I can pinch off the return and only get 27 psi, it should put out up to 100 psi. Or the inlet screen in the pump is plugged, not very likely, I think.

So it is off to find a replacement pump, GSL-392 Walbro. That is the technical name for it in case anyone needs to know.

Will repost when fixed. Later

 

[Tinman]

I had one crap out at about 1 year and <15 miles. Richard warrentied it for me, but I'm beginning to wonder about the is pump. I'm trying to decide whether or not to change fuel canisters with my wife's Liberty. I don't want to get rid of my backup stock pump if the Walbro might quite.

 

[JBallou]

Getting one from summitt racing. $ more than e-bay but no account, don't need the temptation. When I get that new one I will see if I can get the old one warrentied. GDP didn't have any. Then I will have 2 new ones. Every moving part can fail on anything. No chicken little for me here.

I think that the walbro failure rate is small, just like the others, FASS, Air Dog, etc. Good luck finding a FASS pump if a failure on a sunday from advanced autoparts. Who knows, I will keep running what I got for now.

 

[JLovas]

You've maybe thought of this, but is it possible that the pre-filter ahead of the Walbro is getting plugged? A starving pump could act like that too.

 

[MickeyMiller]

IF the pre-filter is getting plugged, you have some real junk in your fuel tank! I changed my pre-filter after one year and cut it open. There is just a wire mesh cup inside... will only stop real BIG stuff. My mesh was clean, nothing caught on it after one year ~17K miles.

 

[BDaugherty]

Instead of speculating on what could be wrong, why not take a look at it? Adjust your regulator and/or take everything off the truck and inspect it. There's nothing wrong with a little troubleshooting.

 

[JBallou]

Chill out BDaugherty, If you have read the above, it states that I did the needed troubleshooting. All except dropping the tank. . yes I could do that to make everyone else happy but I am satisfied with the diagnosis of a bad pump.

Pinching the return showed 27psi, the pump should put out more, adjusting the valve will have no effect here.

Removed the screen just before the pump and blew thru it and felt no resistance, both of the other filters have been changed 2 mic and canister pump. It is not a resistance problem. Period.

Checked the relay and all of the associated wiring. Have good voltage.

What else do you think that I should do? There is nothing left to inspect.

Rant off.

 

[JBallou]

Put in the new pump, pressure is now a solid 20psi. The pump was bad, will send it out to be checked for warranty. Will now have a spare in the box, I don't know about how long the walbro will live on my truck. Just an FYI for others that have a walbro, keep an eye on it.