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  #1  
Old 10-30-2021, 10:11 AM
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Fuel tank "Jet" pump?

It was suggested maybe my Jet pump is clogged on my SVX. Is this something that can be cleaned out or will it need to be replaced?
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1997 Boudreaux LSi
1994 SVX LSi(SOLD)
Kool Blue air filter, 4500k HID's, airbox mod, Hella horns, WRX 6 disc stereo, Infinity Reference and Clarion Pro Audio speakers, Infinity basslink sub, ECUtune Stage 1v5, ECUtune TCU, Power mode mod, Mad muffler mod v1.3
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  #2  
Old 10-30-2021, 12:38 PM
irox irox is offline
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Re: Fuel tank "Jet" pump?

What symptoms are you seeing?

The fuel pump isn't too hard to replace (a little bit of pain), although after doing it once, and then finding out my problem was else where, I would be weary to do the replacement again unless I was certain the part had malfunctioned.
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  #3  
Old 11-03-2021, 11:00 AM
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Re: Fuel tank "Jet" pump?

Quote:
Originally Posted by irox View Post
What symptoms are you seeing?

The fuel pump isn't too hard to replace (a little bit of pain), although after doing it once, and then finding out my problem was else where, I would be weary to do the replacement again unless I was certain the part had malfunctioned.
When I get to about 1\4 of a tank the car will sometimes die coming to a stop and when I go to fill it up it only takes about 10 gallons. If I stay above 1/4 tank I don't have any issues.
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1997 Boudreaux LSi
1994 SVX LSi(SOLD)
Kool Blue air filter, 4500k HID's, airbox mod, Hella horns, WRX 6 disc stereo, Infinity Reference and Clarion Pro Audio speakers, Infinity basslink sub, ECUtune Stage 1v5, ECUtune TCU, Power mode mod, Mad muffler mod v1.3
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  #4  
Old 11-05-2021, 02:52 PM
irox irox is offline
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Re: Fuel tank "Jet" pump?

When I replaced my fuel pump, it turned out to be the MAF (well after replacing the MAF twice it turned out to be the MAF connector...).

If it's really consistent about not running under 1/4 tank, you may have debris in the fuel that are clogging the pump in take or something along those lines. There is a mesh sock around the fuel pump, to stop debris from getting in, so it would have to be pretty bad to in there to clog it. There is an inspection panel behind the rear seat (which you need to remove iirc), you can get to the fuel from there - maybe check to see if there is build of crud on fuel pump sock.

I would also check as many other things first, see if there are any stored error codes, make sure all electrical connectors are correctly seated, etc. before getting into the fuel tank...

Good luck!
Ian.
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  #5  
Old 11-05-2021, 08:16 PM
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Re: Fuel tank "Jet" pump?

Quote:
Originally Posted by svxash View Post
When I get to about 1\4 of a tank the car will sometimes die coming to a stop and when I go to fill it up it only takes about 10 gallons. If I stay above 1/4 tank I don't have any issues.
There's not a secondary pump - there is another tube assembly with a smaller sock on it and a separate fuel level sending unit that goes into the other side. It's connected to the main pump assembly with a section of rubber fuel line that passes over the middle - maybe that's developed a leak or has a loose clamp? It's easy to check, it's right on top when you pop the tank cap off under the access panel. Look for the hose bent in a U shape that doesn't have any connections to the cap. I can't remember if you can see / inspect the entire thing from the top without removal of the whole assembly.

Looking at my pics of the fuel pump assembly from when I dug into mine over the summer, there's also a yellowish plastic piece mounted directly next to the fuel pump itself that joins the crossover tube and I think the return line. It looks like it possibly uses vacuum to pull fuel from the other side of the tank? You could check that for cracks or damage as well, since (if I'm right) that may cause the same issues, although this will definitely require removal of the fuel pump assembly. It's really not a bad job, although not something you want to do in an enclosed garage.

e: Pulled the pics from my phone.

Hoses under the cap (the crossover one is the bumpy looking one on the left:


Fuel pump assembly. I'd check out the yellow piece on the side of the pump:


Main fuel level sender assembly - the little can contains the sensor that triggers the "low fuel" light:


Secondary level sender assembly and fuel pickup for the side of the tank opposite the pump:
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Last edited by Black88GTA; 11-05-2021 at 08:36 PM. Reason: Added pics
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  #6  
Old 11-09-2021, 06:12 PM
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Re: Fuel tank "Jet" pump?

Quote:
Originally Posted by irox View Post
When I replaced my fuel pump, it turned out to be the MAF (well after replacing the MAF twice it turned out to be the MAF connector...).

If it's really consistent about not running under 1/4 tank, you may have debris in the fuel that are clogging the pump in take or something along those lines. There is a mesh sock around the fuel pump, to stop debris from getting in, so it would have to be pretty bad to in there to clog it. There is an inspection panel behind the rear seat (which you need to remove iirc), you can get to the fuel from there - maybe check to see if there is build of crud on fuel pump sock.

I would also check as many other things first, see if there are any stored error codes, make sure all electrical connectors are correctly seated, etc. before getting into the fuel tank...

Good luck!
Ian.
There aren't any codes I could see and since it's only taking 10 gallons to fill it seems the pick up on the other side of the tank might be the problem.
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1997 Boudreaux LSi
1994 SVX LSi(SOLD)
Kool Blue air filter, 4500k HID's, airbox mod, Hella horns, WRX 6 disc stereo, Infinity Reference and Clarion Pro Audio speakers, Infinity basslink sub, ECUtune Stage 1v5, ECUtune TCU, Power mode mod, Mad muffler mod v1.3
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  #7  
Old 11-10-2021, 10:55 AM
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Re: Fuel tank "Jet" pump?

Quote:
Originally Posted by Black88GTA View Post
There's not a secondary pump - there is another tube assembly with a smaller sock on it and a separate fuel level sending unit that goes into the other side. It's connected to the main pump assembly with a section of rubber fuel line that passes over the middle - maybe that's developed a leak or has a loose clamp? It's easy to check, it's right on top when you pop the tank cap off under the access panel. Look for the hose bent in a U shape that doesn't have any connections to the cap. I can't remember if you can see / inspect the entire thing from the top without removal of the whole assembly.

Looking at my pics of the fuel pump assembly from when I dug into mine over the summer, there's also a yellowish plastic piece mounted directly next to the fuel pump itself that joins the crossover tube and I think the return line. It looks like it possibly uses vacuum to pull fuel from the other side of the tank? You could check that for cracks or damage as well, since (if I'm right) that may cause the same issues, although this will definitely require removal of the fuel pump assembly. It's really not a bad job, although not something you want to do in an enclosed garage.
Here's the info on the "jet pump" Also how long did it take you to pull the pump assembly?
Attached Images
File Type: png jet pump.png (212.6 KB, 14 views)
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1997 Boudreaux LSi
1994 SVX LSi(SOLD)
Kool Blue air filter, 4500k HID's, airbox mod, Hella horns, WRX 6 disc stereo, Infinity Reference and Clarion Pro Audio speakers, Infinity basslink sub, ECUtune Stage 1v5, ECUtune TCU, Power mode mod, Mad muffler mod v1.3

Last edited by svxash; 11-10-2021 at 10:58 AM.
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  #8  
Old 11-12-2021, 12:14 AM
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Re: Fuel tank "Jet" pump?

Quote:
Originally Posted by svxash View Post
Here's the info on the "jet pump" Also how long did it take you to pull the pump assembly?
Ah, I was thinking you were referring to another electric / mechanical pump assembly, not just the vacuum device that pulls from the other side. Hadn't heard that part called the "jet pump" before, although I haven't had much reason to dig into it until recently. This and the crossover hose would be the first things I'd look at to try to solve the problem.

It didn't take long to pull, I want to say less than half an hour from start until all of the pieces were out. It's pretty straightforward, although (once everything is disconnected) you will have to rotate the individual parts in the tank a little bit to coax them out. It's much better to do this when the tank is close to empty than full, obviously. I placed sheets of corrugated cardboard with plastic on top all around the tank opening so I wouldn't get gas all over my interior when I took the pump parts out. There wasn't much spillage, but enough where I was glad I had the cardboard out.
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  #9  
Old 11-20-2021, 03:24 PM
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Re: Fuel tank "Jet" pump?

I pulled everything out and it all looked good. I blew out all the lines just to make sure. It looks like maybe it had been replaced before as it was a Carter pump. I put it back together and so far so good.
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1997 Boudreaux LSi
1994 SVX LSi(SOLD)
Kool Blue air filter, 4500k HID's, airbox mod, Hella horns, WRX 6 disc stereo, Infinity Reference and Clarion Pro Audio speakers, Infinity basslink sub, ECUtune Stage 1v5, ECUtune TCU, Power mode mod, Mad muffler mod v1.3
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