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Su fuel pump

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Jeepster

Jeepster

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Does the standard su fuel pump on my BJ8 have an internal filter?

i have an intermittent fuel blockage somewhere and need to clean out and check everything. I have an in line filter between the tank and the pump but need to know if there is maybe a gauge filter in the pump somewhere?
 
Jeepster said:
Does the standard su fuel pump on my BJ8 have an internal filter?

i have an intermittent fuel blockage somewhere and need to clean out and check everything. I have an in line filter between the tank and the pump but need to know if there is maybe a gauge filter in the pump somewhere?
Click to expand...

There is a small wire mesh filter on the inlet side (and maybe on the outlet, too, don't recall for sure). To get at that filter(s), you have to undo the six screws that connect the the pump head to the solenoid body. Then, you'll see the inlet and outlet ports (in the pump head) and, IIRC, there is a plate that holds the filter and valve assemblies in each port. There's a gasket between the head and body, and if you're careful you might be able to reuse it.

Be sure to note how everything goes on dis-assembly, the inlet/outlet flapper valves are identical but must be oriented properly.
 
As Bob said, it is wire mesh, but I'm not sure I would call it a filter. If you have an in-line filter between the tank and the pump, I would think that would catch any and all crud. The screen will only catch big stuff by comparison. Are you sure it is a blockage? I had a fuel starvation problem on my Sprite and I too thought I had a blockage, but the filter and the screen were perfectly clean. Since I have a clear filter housing, I was able to see that I was getting lots of air in the fuel line. The pump seemed to be clicking inconsistently as well. I did two things at the same time (so I don't really know what fixed it exactly): I replaced the pump, and I renewed all the flexible portions of the fuel lines. No more fuel starvation, and no more air in the lines.
 
I had fuel starvation problems twice before.

The first time was a plugged fuel tank sump that was easily unblocked by using an airhose and disconnecting the tank fitting and blowing back into the tank.

The second time was blockage in the fuel line between the tank and fuel pump and was fixed after I isoalted where the blockage was and cut the fuek line in that location and reconnected it with a piece of fuel line rubber hose. I would recommend that ALL fuel lines be disconnected and using an airhose blow out all of the fuel lines. You will see crud come out if the lines have never been blown out before! On rehooking up the fuel lines to the fuel pump be sure that you use new gaskets on those banjo fittings.
 
As long as we're digressing from the original question, I'll write the dissenting opinion (SCOTUS was busy today). I have only the stock wire mesh 'filters' in the pump and the thimble-shaped screens in each carburettor. AFAIK, the smallest passages in the fuel delivery systems are in the float bowl metering mechanism. I have Grosse Jets in my BJ8, and I'm not sure how big the openings are but our BN2 uses regular needle valves and I'm guessing the opening is about 1/32"; so, as long as anything that size or larger is screened out the smaller stuff will pass through causing no problems. Hence, the wire mesh screens in the pump and carbs are sufficient IFF ('if and only if') your fuel system is clean and otherwise in good nick. If not, a paper filter is only a 'bandaid' on the problem. I've also seen aftermarket filters with plastic screens and, although the mesh appears a bit finer than our wire mesh filters basically do the same thing. I put a new tank in the BJ8 probably 15-20 years ago, and sealed it well with the Bill Hirsch tank sealer. I've put about 130K miles on the car in 30 years' ownership, and averaged 5-6K miles/year for the past 20 years and haven't had any problems with fuel delivery attributable to contamination (the fuel pumps, however, are a different story and gasahol seems to cause some vapor lock issues). I've never found any crud at all in any of the screens. If you plan on doing any 'serious' driving and your fuel system components are original or just plain old bite the bullet and replace everything--except the pipes if they're OK--from the tank forward (including the tank--decent aftermarket ones are available). Your fuel-injected Bugsmasher 2000 needs a serious fuel filter, your Healey doesn't.

OTOH, went to start the BN2 the other day and it ran like crap. Checked compression thinking we might have a stuck valve and got 170-179psi on all four (yippee!). Pulled the float bowl lids and, lo and behold, the front bowl was as dry as a California reservoir. The rubber-tipped ('Viton?') needle valve was stuck. Have tried Grosse Jets on this car and one of them sticks, too (had great success with old ones on the BJ8; have heard quality has gone down over the years). Now looking for brass-tipped needles (had a pair but lost one).
 
Sorry Bob, but I've disassembled many SUs that were packed with little bits of crap that got past the screens. Each one may be small enough to pass, but when the get together they have no problem blocking the passages.
 
Jeepster,

If your fuel tank is original then its likely to be full of crap and/or corroded. I had that problem with my first Healey and it drove me mad until I bit the bullet and bought a new alloy tank. Take the tank out and flush it and see what comes out.
 
The tank is original but I sealed it with the resin sealer last year.

Just whipped the tank out for inspection and looking into the sender hole I could see what looked like strips of clear plastic. I pulled a few out and came to the conclusion that the sealant has started to separate from the tank. I'm hoping this is what's causing the blockage so ordered a new tank.
 
DerekJ said:
Definitely the right decision. Its not worth the effort trying to have them sealed.
Click to expand...


Correct. Wish I hadn't bothered patching the old tank and adding the sealer. Should have gone for the new tank from the off.
Hindsight is a wonderful thing!
 
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