Yesterday I made a trip to the store to pick up some things. I pulled the plug on the ICP in the parking lot for the ride home to see if there would be any differences. Upon turning the key I see the engine light come on...don't remember that happening before with just the unplug...then when I crank it up it idles about 200rpm faster. I continue on home noting the tone of the engine is different, but it seems to run somewhat the same with the black smoke and flat spot. When I pull into the driveway the engine definitely doesn't sound happy with what sounds like a slight fuel knock. I shut it off, plug the ICP back up, and crank the truck back up...no engine light, idle rpm back to normal, and no odd engine tone. I will hook Forscan up and check for codes later today...

Oh, I have also pulled the air filter for a run to rule that out. Though I have the AIS, the filter minder doesn't go past the first mark with the filter in and running it up to the upper rpm flat spot, but I wanted to rule this out anyway.

 

I think this just shows that the ICP sensor is not likely to be the culprit since it was running off the default tables to manage the IPR solenoid.

It will be interesting to see the actual ICP values. Pikachu likes to see the ICP voltage since that helps rule out wiring but I’m not able to make sense of those numbers. I would log the event to include those as well though.

I personally think fuel volume is the most likely cause right now. Hopefully you can get a gauge on it soon.

 

I put the truck back to stock and hooked up Forscan yesterday and nothing stood out. The day prior I disconnected the ICP after startup when the engine was cold and I get the bump in rpms like expected. I took it out and ran it through the gears and it comes back to a couple hundred rpm higher idle and the engine cackling not happy. I was unable to get some information running down the road given the battery on the laptop went caput. While I was loading the tune back in the truck I noticed the fuel pump making some racket...it's a Bosch pump, but been in there for years...so you may be on to something. I have a new in the box Bosch pump and a Diesel o-rings fuel bowl rebuild kit with fuel pressure adapters sitting here on my desk that I'll get into over the weekend...I've been putting it off thinking my problem was a boost leak. I just rebuilt the fuel bowl on the Excursion which also has the stand pipe gutted, so I'll plan on doing that too while in there...


...from EBP valve delete...


...taken when engine cold...


...taken when engine warmed up a bit...weird that the coolant temperature started at 32* (it's probably mid to high 80's) and took some time to get here though the truck was up to operating temperature...

 

I found the problem. Yesterday I replaced the noisy fuel pump with a new unit. When I started the truck I noticed the new one was making a little noise, but not as bad as the one that came out. I took it on a drive and once up to operating temperature I hit the throttle. It ran really good and pulled hard all the way through the rpm band with very little smoke...even set a SES light that went back off later down the road. Pulled over and sure enough it pulled the filter minder on the AIS about 3/4 of the way. I got back on the road and noticed it went back to doing somewhat to what it was doing before though not as bad...still pulled the filter minder 3/4, but still had some smoke in lugging it from 50mph. When I got home I took a look at the pre pump filter and it had so many bubbles I thought it was water in the fuel. Figuring the filter/hose assembly between the hard line and pump may have a leak somewhere, I pulled the one off the Excursion knowing it has no issues, but it still had alot of bubbles. The tank is about half plus full and it has the hutch/harpoon mods done many years ago with no pickup foot and compression fittings. I'm thinking the air has to be coming from the connections/o-rings in the flexible line between the top of the pick up line to the hard line on the frame given they come almost immediately when the pump comes on, which is why I thought it was in the line pre pump filter assembly. When I did the hutch/harpoon mod many years ago I did so by pulling the bed since I had a big LULL forklift at the time. I didn't replace that line since the connection to the hard line on the frame is not really accessible with the tank in place. I tried wiggling the connections to see if it would help slow down the amount of bubbles, but it didn't. So at this point I'm thinking it's time to pull the tank unless someone has some further thoughts...I know, I know the worm clamps were from many years ago when I did the mod...

 

Hey there's some fuel in your air.

Good find tho, and a fix you already have experience with. I'd replace the entire hose from the tank to the in-line fuel filter. And check inside the tank to see if a connection got loose.

And fuel injector clamps ftw!

 

It will be the first time to drop a pickup style tank...the Excursion is really easy to do given the metal skid plate. I've been there a couple times for the Excursion, and looking at a third time given the fuel level sender is all wonky now...suspect them tree varmints may have chewed the wiring...plus it's time to replace the flexible lines in it to after seeing this. I'm hesitant about side stepping the frame rail hard line for rubber fuel line as I suspect a tree rat may have chewed on the flexible line as I'm seeing alot of leaves and smaller limbs up in there. I can understand the leaves, but the limbs couldn't just blow up in there. If that's the case...time to wage war again...

 

Well, problem solved though I had to pull the tank half way back down given I had the new lines crossed, but I have 0 air bubbles. Overall dropping the tank wasn't bad once I pumped most all the fuel out of it...that was actually a longer process. I took the truck out for a run through the gears today and it runs better than it ever has...even after the turbo work...and I think it was a slow progressing issue relative to leaking o-rings at the disconnect on the pickup. Once I pulled the sender/pickup assembly, it was dirty, but still solid...I think I originally did the H&H mod more than 20 years ago. I cleaned everything up, tested it, and re-installed it. So @RacinJasonWV was in fact on it...thanks ole Hotrod buddy. In running it...not sure which program I have installed...the air filter minder will pull down 3/4 of the way on the AIS and will set an SES light on hard acceleration, though the light will go back off once driven decently down the road a bit. I cut both the supply and return lines on the frame rail and replaced them with rubber fuel hose. So now I'm going to pull the fuel bowl to rebuild it and get the fuel pressure adapter on the lower passenger side port. I'm also going to pull the tank on the Excursion and see if I can find out why the gauge is stuck on Empty, though I expect the wiring between the frame rail plug and the pickup sending unit. This will also give me a chance to cut the lines on the frame rail to do away with the disconnect o-rings, and install rubber fuel hose. Hopefully I might get a chance to get the other AIS unit I have for it, along with doing the secret Zoodad mod done on it...

 

if the Air Filter Minder is pulling down, you need to replace the Air Filter.

made a huge difference on my truck... when I bought it, the filter was oil soaked, or wet with rain??

I was climbing a steep grade at Loveland Pass in Colorado while towing and it set the code for the filter minder, had to back off and drive like an old lady going to church.... at the time, not knowing anything about the 7.3L that was just acquired, I took it to a big diesel shop, they fixed me right up.

 

Congratulations! @Wes444 actually called it in post #9. FTE has a good team!

Just a note about the fuel level. Dad’s 2000 was always showing as full. I found a broken wire for the sender. So I’m assuming open circuit displays full and the needle goes down by grounding the wire. Since your’s is always showing empty, I’m guessing maybe there’s a short to ground somewhere.

 

No sir. The AIS is borderline when using a hot tune and heavy foot. It filters excellently but the box can become a restriction when ramping engine speed and boost up quickly. Even so, the performance is enough to support even while mostly pulling the minder in.

Opening the side of the box into the fender can help ease the restriction a bit.

All that said, with my current setup mine doesn’t pull in too far. Adding the fender mod and not driving like I did as a teenager keeps it in check. Towing the enclosed trailer in the 80hp tow tune recently saw no appreciable movement of the minder. Typically it may only go up about a 1/4 under all my “normal” driving conditions.

So bwguardian, have you completed the fender mod? lol

 

 

Glad you were able to figure out the issue Guardian. This community is a great one indeed!

 

@Wes444 did allude to fuel pressure, but you keyed me in on fuel volume, which while they do go hand in hand, it was a wording thing that lead me to the air in fuel. Regardless, I wish to thank you both as there's always a different interpretation that will lead one in a different direction. That's what I love about this community...everyone is trying to solve an issue with different ideas, but in such a way that there's no back and forth which leads to harsh feelings.

Thanks for that insight, the ground was the issue here with my F350...fuel gauge did fine until half tank, then would go to full again and work back to half. You can see how crusty that plate is where the sender mounts to. I contemplated bolting another stainless steel plate to it like the newer ones have, but it did go 20+ years and the tank was actually not that bad to pull. Not to mention the price of just the sender...even looked into the oem supplier Herko...is as much as the entire pickup assembly. I looked into them for the Excursion pre Covid, and I could get them from Herko for $5+- at the time...they are almost a Benjamin now...

 

It's a brand new blue Donaldson filter...and more of an air flow restriction as @RacinJasonWV aforementioned.

 

I have not, but will pull out the stock OBS filter box assembly I have to start looking into how to marry that fender application part to the AIS box. Do you experience the SES light coming and going under hard acceleration...I'm thinking it has to do with what the MAP is seeing relative to increased boost pressure...