I have some real data here on this one. I use the fuel additives and I have a fuel pressure gauge. My pressure dropped significantly with cold weather and the fuel filter right at the 10K mark. I swapped the filter and the pressure jumped right back up - same fuel in the tank and same temperature outside.

 

No kidding ! Thanks for the reply Rich, I am on your side of the state this week. It's a bit chilly as you know, but it isn't fuel-gelling chilly. Very interesting info about your fuel pressure/filter discovery.
Do you have any thoughts about the fuel pump, as it relates to my symptoms ? Changed out the CPS last night, that didn't resolve the problem. I carry a fuel filter behind the seat, so I will change it out and see if that does the trick.

 

Also, what additives do you use ? I just dump a little Stanadyne in every now and then. Hoping it helps the injectors, but it might just be snake-oil ...

 

Considering the weather your in and roughly skimming over the thread, I'd think a leaky windshield. Check under the ebrake for moisture, or rip dash bezel off, unplug light switch and take a look atop the fuse and gem modules

 

That's a good thought, I will check it out today, thank you. I live in rainy weather, so I sealed the windshield very well long ago, but it's worth taking another look at. I did it to keep out water and pine needles, the bane of my existence ! FWIW I have never seen moisture inside the cab or under the dash, but I will look higher up under there now.

 

From my experience, without physically removing and resealing the window, you'll never get a water tight condition.
Mine, would drip from the sheet metal screw from the ebrake. It was then, I traveled upword to the gem, to find the puddling. Once new window was installed(had a crack) was when water stopped penetrating

 

Thanks brother, good to know. I have been lucky and haven't cracked a windshield in years. I will get back to you on the leak search. It is a possibility.

 

I just dump a little Stanadyne in every now and then. Hoping it helps the injectors, but it might just be snake-oil ...
__________________________________________________ ______________________
Not snake oil at all. It was developed by the injector manufacturer (don't recall which one though) for lack of a good available product. There are others on the market as well.

 

Ford sells some stuff over the counter, I use that from time to time. I also use the Diesel Kleen stuff - white bottle for winter. I've tried so many additives and I don't see or hear any difference in my new-ish injectors. All I can say is the lubricity is the key thing, then the cetane bump doesn't hurt. Once in a while, I run one tank without additives to purge the system of the additive cocktail that builds over time.

I don't suspect the fuel pump, low fuel pressure makes a horrible knock and a lot of smoke. Of course... without a fuel pressure gauge, I can't make that call for sure. As far as pumps go - OEM, OEM, OEM. Before upgrading my injectors, I did exhaustive research on the fuel pump. What I learned was this: The vast majority of fuel pumps out there are not diesel rated, and nothing that handles the flow/pressure of our 7.3L lasts longer than the OEM. The 044 is a racing pump - look it up. Racing parts are made to outperform everything else with all other considerations taking a back seat, as opposed to doing the daily grind year in and year out.

 

Stanadyne fuel additives were developed by......Stanadyne. the manufacturer of many mechanical fuel pumps. Including the db2 found in the old Ford IDI trucks. They knew they had a problem when low sulfur diesel was mandated way back in the day. As sulfur was the key lubricity component in diesel. Our powerstrokes were meant to run on low sulfur fuel, but this ultra low sulfur fuel needs a little something in it to keep our trucks singing along.

I've been using Stanadyne for a very long time. It makes my IDI sing like a chorus of angles, instead of sounding like a bucket of bolts heading down the stairs. Though I'm not convinced it's any better on the heui injectors in my powerstroke, than anything else.

 

In the beginning I was hesitant to use any additive, but I did have concerns with the ulsd fuel. When I asked around, I got the same answer again and again. Stanadyne. I don't use it on every fuel up, but I try to use it regularly. I figure it's cheap insurance, cheaper than premature injector failure. Definitely interesting that the injector manufacturer created it. There are probably lots of additives that will increase lubricity, so maybe it doesn't matter, but I use Stanadyne. I am sure opinions will vary ...

 

Very common misunderstanding here. Sulfur is not a lubricant, so removing it does not hurt anything at all. What does hurt the fuel, as far as our systems are concerned - is the process of removing the sulfur also removes lubricity and lowers the cetane. Here's where things get sticky... the oil companies know their fuel ain't what it used to be, and so do the regulators. The regulators came up with "thou shalt not allow more than XYZ wear on fuel components because of what we made you do to the fuel, oh... and keep the cetane level above ZYX".

In answer to new regs since 2006, the fuel companies mix in additives at their facility before delivery to the fuel station. However - these additives make the fuel comply in the tanker, but time can allow those additives to escape by way of evaporation or conversion. In the state of Washington, they regulate the fuel to include 5% biofuel (according to my sources) - which has a very high lubricity factor. Biofuel degrades with time, so low-volume fuel stations are more inclined to serve up stale fry soup instead of the diesel we know and love. So... the fuel additives we pour in augment the fuel to compensate for what was lost between the fuel tanker fillup and the injector burn. Keep this in mind if you plan to let your truck sit with a full tank for extended periods.

 

Thanks Rich. Interesting and informative as always. Sounds like different mechanism, but the same ultimate result. EPA meddling has managed to screw up diesel fuel as well. Figures tho, that is what they do best.
As far as practical application then, it's more important to use a good quality additive, than what brand that additive actually is. Along with that, is it then more important to use a fuel stop that has high traffic volume, rather than a high quality one, such as Shell, Chevron etc ? Or am I not on target ?

 

As to the fuel pump, like most all parts, I agree OEM. I understand that the Bosch model is the OEM equivalent replacement. It may not be the culprit I am looking for, but it's almost 20 years old, and not expensive, so it couldn't hurt to do a quick R & R on that item.

I will have to make due with just back blowing out the supply line for now. When I get back home, I will probably have to drop the tank, finally, and do the usual popular mods. Or maybe some variation ...

 

Bosch is the manufacturer of the OEM pump - they won the bid. So... if it is a Bosch pump spec'd for a Ford Superduty with the 7.3L - then it's most likely OEM.

The high-volume traffic factor outweighs the brand factor. I'm not going to imply Joe is better at maintaining the integrity of his tank than Shell does, but when the quality of the delivery system is equal - a significant volume difference will draw me in. Think Fred Meyer diesel near town with a discount and 4 pumps vs. Art's Shell with the single diesel pump out back.