Can a clean looking filter still be restricting fuel?

[Conflict]

• Truck died while driving. No fuel pressure. Changed filter. Fuel shooting out of the schrader valve and truck runs fine. I can blow air through the filter easily. Open the filter and it looks clean. Could it still have been restricting totally? Every time I turned the key the pump was humming. Suggestions? Change the pump just in case? Look in the tank for crud? Tank seems plastic. Were they all plastic for 2wd manual 2001 B2500's? I'm tempted to remove everything and put in 2 smaller tanks with their own pumps? I don't like not knowing the cause.

 

[cbxer55]

Guess it's just like a fuse looking good, but being bad. Or a spark plug.

I recently changed my fuel filter, hadn't done so in probably 10 years. Could not blow through it.

What gets me is why they even need the secondary filter. There is a sock on the pump to keep it from getting plugged up. Despite that, the inline filter still gets plugged up. My three motorcycles have the pump filter only, no inline filter to be found.

Things That Make You Go Hmmmm.................................

At the same time as the filter, had a really dirty MAF. Spray wouldn't remove the brown stuff that was on the upwind side of the wires. Had to use a q-tip and alcohol to get whatever it was off. Felt kind of sticky. Don't know how that got there. New filter and clean MAF fixed it right up. Previously, the MAF was not working. If you pull the plug while the engine is warm and running, and it keeps running, the MAF is not working. Cleaned it and it works now.

 

[pjtoledo]

so it's running now?
just looking for why it died?
try looking at the connector and wires attached to the inertia cut-off-switch.
if your pump is 25 years old I wouldn't feel bad about replacing it.

 

[JoshT]

What gets me is why they even need the secondary filter. There is a sock on the pump to keep it from getting plugged up. Despite that, the inline filter still gets plugged up. My three motorcycles have the pump filter only, no inline filter to be found.

Fuel pumps work better at pushing fuel than at pulling it, you want as little restriction as possible before the pump. Large micron sock filter in the tank stops large debris that would damage the pump, but still permits a large amount of flow with little restriction. Small micron filter inline stops contamints that may clog or damage the injectors, but would pass by the pump harmlessly. Some modern vehicles only have a single filter in the tank and it's intended to last the life of the vehicle, of course we all know how those intentions go.

For the motorcycles, I would assume that it has a lot to do with size. Due to the small engines and small size of the fuel system, they probably require a lot less fuel flow. They probably do fine pulling through a much finer filter. Smaller fuel batches, typically much more involved owners with more careful maintenance, easier to access the filters for replacement. All speculation.

 

[cbxer55]

Easier to access? LOL.

Remove seat. Remove side covers. Remove speedo housing on top of tank. Drain all fuel from tank. Remove tank. Turn tank upside down. Remove pump from bottom of tank. Disassemble pump. Change filter. Reverse all the above.

Takes two hours on my M109R. Three hours on my B-King and CBR600RR.

Starting in 2018, I keep 15 gallons of 93 in my garage. I use a funnel with two fine mesh filters (I made it) to fill the tanks. I rarely fill them at a ststion. The mesh filters in the funnel tell me most statuons where I live have pretty dirty fuel.

 

[cbxer55]

All three of my bikes have double injectors per cylinder. Primary and secondary. I know from finding a chart, mt B-King, the secondaries, at 8000 rpm and 80% throttle, carry 90% of the fuel flow.

We are talking a 1300 that has more power than a 3.0 Ranger. My CBR600RR, factory stock, is 124 hp.

My M109R, 129 hp.

Small engines. BIG power. All of them can empty a near five gallon tank in 100 miles if you ride them like you stole them.

 

[Conflict]

OK so ya'll think it may have never been the filter... Wiring looks perfect at the fuel cutoff switch. I don't know how old the pump is so I'll just get a whole new pump/float switch cluster. the racing hangers can hold multiple pumps. Is that for redundancy or do they just need extra flow? The tank looks to be plastic so I guess nothing can really go wrong with that as far as contributing debris to clog anything. As far as motorcycles, you gotta have a death wish to ride those things.

 

[85_Ranger4x4]

Just get a replacement pump/hanger assembly, you don't need multiple pumps.

Motorcycles have no relevance for this discussion.

 

[Roert42]

I’ve had clogged fuel filters cause issues. Normally you turn them upside down and brown sludge pours out.

Could be a weak pump, pressure drops when you start driving. Could be a bad wire causing voltage drop.

 

[MISWFL]

How many miles and years on the fuel pump? OEM or aftermarket? Fuel pumps have brushes that wear out. When they start getting short, they can stop making contact, especially if they get canted in the slots. Tapping on them will often get them working again for awhile.

In tank pumps suck vs external but that's the norm now. Just because it's a plastic tank, doesn't mean there's nothing to clog up the inlet of the pump. Do you run some fuel system cleaner like Techron and some water remover regularly? Not sure about your application, but some tanks have rubber in them that degrades with time and can clog up the inlet of the pump. I used to deal with that on water cooled VWs. My solution was to use a glass serviceable filter before the factory external pump to keep the tiny pieces of rubber from clogging and killing the fuel pump.

 

[Conflict]

It was the inertia switch. It happened again on the way back from getting a new pump and I was able to see it with the voltmeter. Jumped it with a scrap of wire and I was back on the road. FYI, Autozone can't get replacement inertia switches for my 01 B2500.

 

[85_Ranger4x4]

At least now you know what is wrong!

 

[MISWFL]

It was the inertia switch. It happened again on the way back from getting a new pump and I was able to see it with the voltmeter. Jumped it with a scrap of wire and I was back on the road. FYI, Autozone can't get replacement inertia switches for my 01 B2500.

RA has a Rostra 760002 for $49.

AutoZone's Z Net system sucks. You can call them and ask for them to punch in that Rostra 760002 part number into the Z Net part number search field. Most likely something they can get will pop up. It'll probably be double or more than RA or Amazon/eBay.

 

[alwaysFlOoReD]

I have a bunch of rangers I'm scrapping out. But shipping would probably kill any good deal. But just in case pm me and I'll price out shipping. No charge for part...