Need help with fuel pump fittings

[M. Holtmeier]

I picked up a Walbro GSL-392 to replace my main pump. The pump has, from what I can tell, metric straight pipe on both ends in m10x1.0. Both fittings that were supplied with the pump are 3/8" barbed end like in the picture. What I need are 90s and one in 5/16" to connect to fuel filter. I don't really want to turn this into an all-out fuel system upgrade with a custom fuel rail and $300 worth of army-navy fittings.

[turbodan]

What I did was simply stretch the 8mm fuel line over the barbed fitting. You can do this with fresh line. Old, dry fuel hose will crack and split. The supply side hose from the intank pump clamps down onto the 3/8" barb just fine. No need for angled fittings either. The stock pump has the same fitting arrangement with loops of fuel line to make the bends.

[Mr Project]

I did something very similar on the E23, but instead of a 3/8ths barbed fitting I have 8mm single-barb. New hose goes right over and clamps down just fine.

Something like this: http://www.ebay.com/itm/3024-Walbro-Fue ... 3744wt_762

I want to say on the inlet side I had to buy a 10mm fitting. I mistakenly thought that I'd be able to find something locally but nothing had the right thread setup for the Walbro, so I had to get one off of ebay. IIRC it was like this.
http://www.ebay.com/itm/ws/eBayISAPI.dl ... 3417wt_762

[M. Holtmeier]

I was going to stretch the hose on, but this pump is longer than the oem, even more so with the fittings installed. The supply hose is entering the wheel well. What about tapping the ends of the pump to 1/8" npt?

[T_C_D]

Are you sure it's metric? i used 1/8npt fittings in mine.

[turbodan]

Are you sure you have the pump, filter and lines oriented correctly? I'm running that exact GSL-392 with those fittings in the stock bracket with the stock line routing. Had this setup on two e28s now.

The supply hose clamps onto the rear of the pump. No loops needed there. You should have a section of hose making a 180 from the pump outlet to the fuel filter and another section of hose making the turn forward from the rear of the fuel filter to the feed line on the way up to the engine.

[M. Holtmeier]

Are you sure it's metric? i used 1/8npt fittings in mine.

No, but the fittings screw all the way in and came with crush rings. I might be screwing some npt fittings in there.



I'll look again at the setup. I just eyeballed it without taking any of the stock stuff apart and thought, "that shit aint' gonna fit." My "giv-a-fuck-ometer" with working on this car is at an all time high. Knowing now that someone else has fit this pump/fittings helps. Thank you.

I wonder how the car will run with a walbro intank pump that doesn't have a ripped inlet hose trying to push through a main pump that runs when it feels like it.

[Mr Project]

I was going to stretch the hose on, but this pump is longer than the oem, even more so with the fittings installed. The supply hose is entering the wheel well. What about tapping the ends of the pump to 1/8" npt?

I tried putting 1/8" NPT fittings on the end but wasn't comfortable with the way it was working at all. I didn't try really screwing them in to cut their own threads to see if it would seal under pressure. Maybe I was foolish to give up so easily?

It's close enough that if it doesn't work with the 1/8" NPT fittings you aren't going to be able to re-tap it to 1/8" NPT. Not enough metal to play with IMO. You'd have to go up a size and I don't know if there's enough meat there for the next size NPT.

[M. Holtmeier]

Yeah, I didn't want to cobble a fitting in there.

I'm not sure if Todd's came with npt or not. Maybe you can order them that way and I didn't research it enough. The one's I found on ebay came with or without an "installation kit."

[T_C_D]

Yeah, I didn't want to cobble a fitting in there.

I'm not sure if Todd's came with npt or not. Maybe you can order them that way and I didn't research it enough. The one's I found on ebay came with or without an "installation kit."

I don't know but it's in and not leaking.

[thrty8street]

Are you sure you have the pump, filter and lines oriented correctly? I'm running that exact GSL-392 with those fittings in the stock bracket with the stock line routing. Had this setup on two e28s now.

The supply hose clamps onto the rear of the pump. No loops needed there. You should have a section of hose making a 180 from the pump outlet to the fuel filter and another section of hose making the turn forward from the rear of the fuel filter to the feed line on the way up to the engine.

Would you recommend using this model instead of the Walbro 255lph (in tank)?

[turbodan]

Not particularly. If anything I would recommend doing the in-tank version. The only thing the GSL-392 has going for it is the ease of installation. Direct replacement of the stock main pump. Having never used the in-tank Walbro I don't know how difficult it is to install, so that might be a non-issue. A drawback to using the GSL-392 is that you're still pulling fuel through the stock in-tank pump which could potentially reduce the flow through the main pump, especially if the in-tank pump quits. I don't know if this is an actual issue but its always good to eliminate a potential problem and simplify the system.

[wkohler]

Has anyone run both the in tank and the external? It seems like overkill, but I've got them both, so I thought I'd ask. I searched and saw someone concerned with amperage. At this point, I'm setting it up to use just the in-tank, but I did get to thinking.

[M. Holtmeier]

I've got a couple hundred miles running both pumps. The circuit seems to be holding up fine thus far, no signs of excessive heat build up yet. I'm still messing around with stuff but for right now the the entire circuit is stock.

[wkohler]

Thanks. What fitting did you end up using? The pump I got seems to have some sort of 3/8 check valve fitting.

[mooseheadm5]

And can you put an ammeter on the circuit to see what the circuit pulls at full clip?

[thrty8street]

Not particularly. If anything I would recommend doing the in-tank version. The only thing the GSL-392 has going for it is the ease of installation. Direct replacement of the stock main pump. Having never used the in-tank Walbro I don't know how difficult it is to install, so that might be a non-issue. A drawback to using the GSL-392 is that you're still pulling fuel through the stock in-tank pump which could potentially reduce the flow through the main pump, especially if the in-tank pump quits. I don't know if this is an actual issue but its always good to eliminate a potential problem and simplify the system.

So for turbocharged vehicles, would you recommend doing the upgraded in-tank (as you described) + bypassing/removing the main pump?

[BATESY]

I personally, on my m106, got rid of the inline pump under the car, due to it locked up on me, and installed a walboro high flow I got from TCD for the intank. Works great, just a crank longer on the first morning start up. Fuel pressure running it perfect. havent had a problem.

Now if your running a stock intank pump, which is new or good, then I could see running a walboro inline under the car. Im my situation my intank went out and installed a walboro in its place. 3k miles later my undercar inline went out.

[maybeillbuyit]

Just my .02 cents on this. I installed the walbro intank pump and it works fine but its noisy. Makes a high pitched whine you can hear inside the car and standing outside beside it. Worse when the tank is below half full. Probably going to try the TRE intank pump when I get around to it.