1990 7.3 Fuel filters keep needing changed ever 20 miles

I am doubting the air intrusion idea.
The OP says the filter light comes on. That light comes on when there is negative pressure in the fuel filter housing, meaning the injection pump is pulling more than the lift pump is pumping.
I can't see air intrusion causing that.
Thewespaul inline filter idea is a good one, in the rubber line near the lift pump is an easy spot. If that stays clear I would just replace the lift pump.
I have had a couple lift pumps go out over the years, some times its sudden,and other times it comes and goes like this.

Air intrusion can happen between the lift pump and ip


Sent from my iPhone using Tapatalk

austin92 said:

Air intrusion can happen between the lift pump and ip


Sent from my iPhone using Tapatalk

Click to expand...

yes, but it wont turn the filter light on.

I'll try that rubber hose idea, but I'm pretty certain it's going to be the lift pump. As for the air intrusion you mentioned it wouldn't buck, but when the light comes on it starts bucking and surging right before it dies. I've hit the shrader valve and have heard no air come out. That said I'm going to check and replace those rubber O rings anyhow because it might be getting close to time anyhow, and it's an easy job.

I had a similar issue when I changed fuel caps. Ours need vented, almost all aftermarket are for closed systems (emissions). Mine died about 10 miles from the house. I loosened the cap (kind of hard because of the vacuum in the tank), re-primed the pump and it ran fine. I went back to the old cap and it has been fine for years.

I installed a Facet electric lift pump in my truck. 120” pull on that baby Prime's everything and even pulls from the tank in almost no time at all. My fuel gauge is broken so I have run out of fuel a couple times. Prime's the fuel filter and runs strong in seconds.

It also has a totally separate fuel filter in a clear container so you can see everything before it makes it to the actual fuel filter.

Easy to install and there is even a full fledged write up on how to do it I the stickies. Just make sure you spend an extra $60 and buy American made pump so you can sleep easy at night.

Would a bad lift pump also cause blue smoke? My truck recently started smoking and it's never done so in the past, it still runs pretty well, and I'm now thinking with about 80% certainty that it's going to end up being the lift pump, but will do some tests before putting in a new one. I would go with the electric pump, but this winter I'm going to convert the truck to a cummins for more pulling power. I'm sure I could get enough out of the IDI, but it would cost so much more money to do so. I love my truck, but the lack of power not so much.

austin92 said:

What he meant by olives is the 2 o rings on each injector that seal the return lines.

Click to expand...

No. The olives are the seals on the hard lines that go into the fuel filter, from the filter to the injector pump, and, in some cases, by the fitting that actually sends the return fuel back to the tank (at the back, driver's side of the engine). Correction: the final olive would be at the return fitting on the top of the injector pump. This hard line does go back to the fitting that I mentioned earlier.

IDIBRONCO said:

No. The olives are the seals on the hard lines that go into the fuel filter, from the filter to the injector pump, and, in some cases, by the fitting that actually sends the return fuel back to the tank (at the back, driver's side of the engine). Correction: the final olive would be at the return fitting on the top of the injector pump. This hard line does go back to the fitting that I mentioned earlier.

Click to expand...

Yeah, I get viton and olive mixed up for some reason.


Sent from my iPhone using Tapatalk

The filter change light is only going to activate when there is a restriction of fuel. When the consumption of fuel by the injector pump becomes greater than what is being supplied by the filter head it creates negative fuel pressure between the injector pump inlet and the filter head. This condition is what triggers the vacuum sensor at the filter head and activates the dash light. That being said, the restriction may not necessarily be caused by the filter. It could be a restriction anywhere between the tanks and the filter. Basically anything making the fuel being supplied to the filter head less than the injector pump demand creates a restriction. That's why you may notice it more quickly with higher revs/greater throttle. Air intrusion will prevent the injectors from building pop pressure but, is not going to cause a sensed restriction at the filter head. If your filter is not actually clogged, the most likely causes are a failing lift pump and/or collapsing rubber fuel lines before or after the lift pump. Don't let the thread die without updating us on the culprit.

Are you sure you do not have water in your fuel?
If you have water in fuel, the filter will fill up with water and displace and block off fuel to the injectors. The engine will die because of lack of fuel to the injectors.

When you install a new filter, it runs for a while, while the water gets sucked or pumped to the filter on it's way to the Injection Pump. When filter fills up with water, no room for fuel, engine dies.

Next time, pour off the contents of the filter you remove into a clear jar, then drizzle some diesel into the jar. let it set for a bit, if there is water, the diesel will float to the top and you will see the line where water stops and diesel starts. Water is heavy, fuel is lighter.

I would lay odds you got a load of water in your tanks.

This would only happen with water block filters, standard filters will absolutely pass water into the injectors.

Stanard filters will also fill up with water, the top of the filter is where fuel is sent to IP. When filter is full of water, you don't get fuel to IP or Injectors, engine dies.

The "Filter plugged" sensor is at the top of the mount bracket. Water breaks the signal and tells him "filter plugged", then, shortly after that, engine runs out of fuel, because the filter is full of water.

BTDT, with water contaminated fuel. Just my suggestion, OP's problem may be different, but it fits what I've experienced.

With water contamination, the ip doesn’t care, it will pump and inject just about any liquid you feed it. Water will cause some funky issues, but I don’t think it’s the cause here.

Water will not trigger the filter restriction sensor, there’s a seperape WIF sensor for that