I've gone through two Walbro in line high pressure fuel pumps, and want to give the Bosch 044 a try to see if I can get some better life. The 044 has a check valve, and the Walbro (GSL392) does not (AFAIK). I know you can remove the check valve from the 044, but I'm curious about the logic; should I simply leave the check valve installed? The car always ran fine with the Walbro and no check valve.

As an aside, I suspect my first Walbro was a counterfeit, as it lasted 30 minutes (Ebay seller). The next one (Summit purchased) lasted around 500 Sunday afternoon miles. I'm running an Earl's 85 micron pre-filter, and a Vette filter/regulator on an LS1. I would have thought it should have lasted a lot longer.
Andy1

 

If you've eaten two genuine Walbros, I would question something regarding your install that is killing them.

And the pump will flow a little more without the check valve, if you actually need that.

So exactly how are they installed, where, exactly what pre-filter, line sizes, lengths, etc etc ?

 

Stevieturbo, Pre filter, pump, and regulator are below the bottom of the fuel tank. -6AN hoses. Stock '01 Z28 LS1/914 Porsche swap..
Yeah, I'm surprised/concerned of the short lives. I will dis-assemble the pre-filter to see if it's clogged. I'll check the fuel tank as well.
The first Walbro simply quit. The second one started whining, then quit.
Andy1

 

I run a 44 and I don't run a pre-filter as they don't recommend it. They have a decent screen in the pump body. I run the high pressure Bosch fuel filter AFTER the 44.

Mine is a fairly new install also, so really not too sure about longevity also.

Dirty pre-filters prior to a pump will kill them everytime.

 

That is vague. I asked for specifics.

-6 supply line to an 044 is too small. And it should be short hose runs.
There is no issue at all with a pre-filter as long as it is a proper one and not a small piece of **** as quite often people choose to run.

Inline pumps like this must always have a good, clean uninterrupted gravity ( or pumped ) supply of fuel.
Failure to have this will kill pumps.

044s do have a mesh screen inside, but it's still good practice to have a good pre-filter

 

Stevieturbo, Hope this photo provides enough info. The bottom of the fuel tank in coincidental with the crease (above the fuel filter/regulator) in the sheet metal bulkhead. Fuel tank has a 3/8NPT x -6AN fitting for the supply line. Supply line to pre-filter is about 24" long.
Andy1

 

I've run a O44 on a few swaps with zero issues. LS1, LS6 and a stroked LS2 to 427 cubes. Always used -6 lines again no issues. Just bolted them on and ran them. Didn't remove the check valve because I didn't know they had one! I've never run a pre-filter but always had the "sock" on the pick up tube.
How is the pump wired? Large enough gauge wiring?

 

That filter is in NO way whatsoever suitable for what you are using it for. It is far too small. That's like something you'd use for a dead headed carburettor setup.

Put a proper filter on it, and up that supply line to at least 1/2" with suitable fittings. And often the M18 fittings at the pump can have tiny holes in them for some reason, if need be drill it out as big as is practical.

 

And where does your return go to the tank ? Some have had issues if the return is too close to the pump supply, as the returned fuel can sometimes be aerated and can contaminate the supply. Ideally it needs to be a bit away from the supply.

 

I know on the old rwd Volvo applications, that pump is always used with an in-tank pump to supply fuel to it. Eventually I ditched it and just went with a solo in-tank pump from Deatschwerks.

 

That Volvo dual pump setup is weird though, my 940 has two pumps.

The 044 and pumps like it were common on millions of vehicles in Europe, single pump, inline, always gravity fed ( except some Volvo lol ), local and underneath the tank with a mesh strainer inside the tank pickup.

Given there is a mesh trainer inside an 044, and if you were pretty sure your tank and fuel supplies were always clean, you could forego a separate filter before the pump.
But in general I would not. IMO, use the biggest 40-100 micron filter you can so there will be zero restriction at all to flow. I've used the these before, https://www.holley.com/products/fuel...arts/230630ERL

Or the equivalent Aeromotive. I've also used 40 micron in the same style without issue.

Are they oversized for the task in hand ? probably....which is exactly the reason I used them. ZERO restriction.

I can only imagine the pump on Andy's car was screaming it's head off trying to get fuel through those small lines and very restrictive filter.

 

I should of looked a little closer but on the 044 pumps that I have used they had barded? fitting not a a -6 on the input side. I had to use -8 that slid over the barded and then I used fuel injection hose clamps to hold it in place. Maybe the -6 line is creating a restriction on the input side?

 

Barded?? BARBED...

 

No 044's have barbed fittings, nor to they have -6.

ALL 044's have M18x1.5mm inlet threads

 

Of my two pumps on my turbo build, one is a genny 044. I don't see the point of a check valve for it, since it runs all the time. My other pump is a Weldon 2345A I have a check valve on that side.

 

Some people just have a fascination about check valves and pressure bleeding off after shutdown. It's a non issue. It may make a small fraction of a difference to starting time, but it is extremely small.

but yes if it is a multipump setup, some pumps may require a check valve.

 

Maybe barbed is the wrong term. Maybe ribbed is a a better description. Yes you need the -6 adapter for the output side.
I don't have the cars any more so I can't take a pic but I could of sworn it was part of the 044 pump not an adapter on the input side. No doubt I could be wrong.

 

NO 044 has a barbed fitting on the inlet.

 

I think what you are referring to is a banjo fitting... These come standard with the 044. The banjo0 fitting goes over the "Barbed" part and allows for swivel action.


https://www.ebay.com/itm/SYTEC-MOTOR...-/264414055903

 

That's the discharge, not then inlet. NO 044 has a barb or anything like it on the inlet.