Inline Fuel Filter

[PeterB]

I am looking at installing an inline fuel filter in my BJ7 and I was wondering if anyone had any advice. I was thinking about a WIX. I wasn't sure if you can cut the flex line that goes to the carbs to install it because I think it is braided steel on the outside. Also can anyone describe how the 2 overflows from the carbs are run down away from the header.

Thxs

 

[AUSMHLY]

Hi Peter,

I installed an inline fuel filter between the gas tank and fuel pump. Things that I install that were not installed by the factory, I try to hide. Installing the filter there should catch anything that comes from the tank before it get to the now second fuel filter which is in the fuel pump.

I've seen inline fuel filters installed in the flex line that goes to the carburetor. You can cut that hose, for it's rubber with a stainless steel mesh on the outside. After cutting it, wrap electrical tape around the ends to keep the stainless steel braid from fraying and it looks like the rubber caps that are used on the outer ends. Then install the clamps over the electrical tape.

As far as which in inline fuel filter is better, WIX vs other brands, I don't put as much weight on aftermarket fuel filters vs an oil filter. You'll have two fuel filters, where as only one oil filter. What the first inline fuel filter does not trap, the second should.

The two fuel overflow tubes from the float chambers travel down and thru a hole in the heat shield. Both tubes will run side by side thru that one hole. Make sure there is enough length on those hoses, so that when running thru the hole, they hang straight down and not pointing or touching the engine or any part of the exhaust.

There are also two long copper overflow tubes that come off the inlet manifold, those travel thru a hole in a "clip" as described in the moss catalog. The clip is a flat piece of metal with two holes in it. One hole that a bolt goes thru to hold the clip to the oil pan, and the other that the copper pipe goes thru. You can make that clip, out of any piece of flat metal.

Cheers,
Roger

 

[andybj8]

I bought a chrome and glass cleanable filter that looks in keeping from eBay. I bought the small petrol flex tube that goes between the two carbs thinking I could put it between the front carb and filter, then move the long petrol flex . Unfortunately there is not much room, so I ended up cutting the long petrol flex tube and reusing the rubber ends from the new carb one. The rubbers just push over the braiding. I had to tape the braiding up and then carefully cut it with a hack saw and side cutters.

 

[HealeyRick]

I bought a chrome and glass cleanable filter that looks in keeping from eBay. I bought the small petrol flex tube that goes between the two carbs thinking I could put it between the front carb and filter, then move the long petrol flex . Unfortunately there is not much room, so I ended up cutting the long petrol flex tube and reusing the rubber ends from the new carb one. The rubbers just push over the braiding. I had to tape the braiding up and then carefully cut it with a hack saw and side cutters.

Although those glass filters look nice, consider what would happen if the glass fractured while the motor was running.

 

[Keoke]

Although those glass filters look nice, consider what would happen if the glass fractured while the motor was running.

Good point use what is refered to as a VW clear plastic filter.--Keoke

 

[AUSMHLY]

Good call Keoke,

That's the style I use. I installed a Fram G2
Here it is again.

 

[andrea]

https://picasaweb.google.com/lh/photo/Xoylf897Q6d3hX183q4dM9MTjNZETYmyPJy0liipFm0?feat=directlink
https://picasaweb.google.com/lh/photo/HJWqrBODwTk1RTipu7ttXtMTjNZETYmyPJy0liipFm0?feat=directlink
https://picasaweb.google.com/lh/photo/ejTok5ielURFNBw3pH3_kNMTjNZETYmyPJy0liipFm0?feat=directlink
King Filter in all two type --Little or Big (with Fuel pressure Instrument)-- is also pressure regulator -Braided tube can be cut but
you must mount a rubber cap (Part Number: FL4381 aHEAD)the CLIPS
go ON it (wrong on my photo)
cheers
Andrea

 

[reddsprite]

I use a wix 33095 fuel filter-its one of the smaller ones that works fine with low pressure fuel systems-I have had no problems and it works great.plumbed in just before the front carb. Its a aluminum filter that is not over bearing in size.

 

[RAC68]

Hi Peter,

This topic has come up in the past.

If you are using an electronic or points-triggered SU pump, it is recommended by SU and Dave DuBois (recognized SU pump expert) that a filter can be installed after the pump and not between the tank and pump. According to Dave, “<span style="color: #3333FF">SU pumps are able to pass most debris right through them without causing any problems. The filters that are built in them are designed to stop rocks and small birds. Placing a high efficiency filter on the inlet side of an SU pump is something to be avoided because if the filter clogs to the point where it will not allow fuel to pass through it, the pump will stall in a current on condition</span>”. If the circuit is left on too long, as in a diagnostic session, the SU coil’s swamping resistor, part of its suppression circuit, will burn out and cause permanent damage to the pump.

A more complete article can be found on Dave DuBois’ web site at https://homepages.donobi.net/sufuelpumps/Fuel_Pumps/SU_Fuel_Pumps_Facts_and_Myths.pdf

Hope this helps,
Ray (64BJ8P1)

 

[AUSMHLY]

Ray, thanks for sharing what Dave DuBois recommends. Interesting logic, that I need to look into more.

"if the filter clogs to the point where it will not allow fuel to pass through it, the pump will stall in a current on condition". If the circuit is left on too long, as in a diagnostic session, the SU coil’s swamping resistor, part of its suppression circuit, will burn out and cause permanent damage to the pump.

If the before the pump filter clogs, the pump will start pumping faster and faster, the engine will shut off letting you know it's not getting petrol. No different than if there is no inline filter before the pump, you hear the pump clicking faster and faster telling you the tanks about out of petrol. Of course you don't want the pump to keep pumping in either example, just pointing out that the pumps fast clicking will let you know no petrol is getting through, and of course the engine will shut off. At that point you turn the key off, which turns the pump off.

Now putting a filter after the pump, if that filter clogs, the engine would shut off too, being no petrol to the engine. The pump should stop working at that point because it thinks the line is full of petrol, so that's a good thing and a reason why one would put a filter after the pump. Either way, your driving and the engine stopped. Pull over and turn the ignition off, which stops the pump.

If the filter inside the pump is designed to stop rocks and small birds, what good is the filter. And how did those birds get in the gas tank anyway...lol
One could say the putting a filter before the pump would stop the small debris from passing through the pump, if the pumps mesh is that large. I did find debris in one of my carburetor screens, that got pass the pumps screen, that it affected the running of the car. After that, I added the aftermarket inline filter.

Question, should the pump filter be checked occasionally to see if it's starting to collect enough debris that it would eventually clog? There's a reason to put a filter before the pump, then you should not have to check the pumps filter.

I placed a filter between the tank and pump (before knowing what Dave DuBois recommends) that is easy to get to and I change it with every oil change. My filter has a clear plastic housing that shows me what it has trapped, which is always very fine, and a very small amount. If one were to see a lot of debris in the aftermarket filter, then the tank should be taken out to find out what's going on, like Dave DuBois mentioned. I have an electronic SU pump and thought that anything I can do to keep clean petrol headed it's way, is better than having it pass through or accumulate in the pumps filter. Maybe I should rethink this, per Dave DeBois. I appreciate sharing of views, for my views (some, well maybe more than one, and I'll deny it) are not always the smart ones.

Cheers,
Roger

 

[RAC68]

Hi Roger,

I, personally, do not see a major issue with having a filter before the SU pump if you are aware of the swamp resister and are willing to take the risk of having a bolder of large bird clog your fuel system. Although I do not have a filter before or after my SU and purchasing dirty gas can happen any time, only once in 48 years did I have a fuel-stopping “clog” and that was caused by my misuse of Form-A-Gasket around the sending unit that fell into the tank about 2 years after use. If it were any other pump, it would be a must, if not a strong suggestion, to install a filter before the pump. But, the SU is a different animal and I would appreciate reading what you find in your further research.

All the best,
Ray (64BJ8P1)