Hello,

I’ve got an early ‘99 7.3 in a van. It’s my first diesel, and it’s only got 90k miles on it, so I want to do my due-diligence to keep it’s performance sound.

I’ve gone through all the fluids, air/fuel/oil filters, replaced the serpentine belt, and rebuilt the fuel bowl just sort of as precautionary measures, since it had sat for quite a while before I got my hands on it. In anticipation of a tuner, I’ve installed a bunch of gauges and got an OBD2 scanner and the Torque Pro app.

Everything seems to be running “ship-shape”, but now that I can see all of these read outs from the Torque Pro app, I’m curious about what I’m seeing from the HPOP.

I feel like I saw somewhere that HPOP pressure shouldn’t ever really be below 500psi, and I read that “bleeding down” pressure can be an issue, as well as a factory test where high injector duty cycle numbers at startup can be indicative of a problem with the HPOP system. And my intended usage for this van includes long drives to remote places, so I want everything to be 100%.

So here’s what I’m seeing. The HPOP system will produce 3,000 psi, BUT, every time I go to start the engine it only reads ~30psi before I start to crank it over (it bleeds off almost immediately
after shut-down). Cranking over the engine the HPOP will get up to about 1,700psi pretty quick, and injector duty cycle spikes momentarily at 70% or so. It starts up quick! And it idles at about 470psi, and 9% duty cycle.

Are any of these numbers indicative of a “tiring” HPOP system, or am I good to go?

Thanks,

Casey

 

Welcome to the forum Casey! Is that a Quigley? We love pics of unusual rigs, btw.

The HPOP numbers you have are fine, but getting some charts while running is far more informative then snapshot numbers. Here is a LINK to a charting tool from the Tech Folders stickied at the top of the forum. There is a learning curve involved but then you have charts we can inspect.

For overlanding there is plenty to sort out. Read the Failure Prevention Thread.

To help acclimatize to the unusual but simple world of 7.3, here's a useful chart below. Shows operation of the HPO system and the fuel system.

And if you have free time after all that check out the Monkeys On the Road blog. Family pointed their 4wd 7.3 van south, and after much adventure (including van repairs) are wintering in Argentina.


HPO and Fuel systems

And a notated map of the top of the engine.

 

Wow! What a response. Thank you for the links. I read through the first several pages of the failure prevention thread; that’s some seriously good stuff, and I’ve got some work to do. So far I have had the van on three ~500 mile journeys and it’s performed more or less flawlessly. The only exception was when we ran our batteries a little low camping and the engine wasn’t cranking over fast enough to start two days later, but I have since replaced them with a pair of Odyssey Extremes, and I don’t think that will be an issue moving forward (we also plan to add some sort battery monitoring system and dedicated house batteries before too long).

I also checked out the link to the charting software, and it looks like it will support Torque Pro, so I’ll try to figure that out and update this thread when I do. Am I trying to chart just the start-up, or should I put it through it’s paces?

As for the van, it’s a home-brewed build using parts from U-joint Offroad and Weldtec Designs. Chris @ U-joint sells the suspension lift (6”) and 4x4 conversion pieces, as well as the front bumper. The rear bumper is Weldtec, and the tire carrier is my own concoction. I rebuilt both a 2004 F-350 D60 front and the van’s original FF D60 rear with Eaton True-Trac diffs and Dana-Spicer 4.10 gears. My buddy who is sponsored by Toyo got me some of their 35x12.50” M/T’s. I added a 12,500 lb Warn winch and seats from a 2014 Honda Odyssey (on Sportsmobile swivels).






I actually still need to finish the 4x4 conversion. The stock 2WD transmission needs to modified to accept the t-case (not a lot of room under the van to run a divorced unit). And the interior is still just empty stock cargo van, but I’m planning a full build out. I’ll keep you guys posted, but if you have Instagram check out @ExcellentAdventurevan where I’ve been posting the build (including the before pictures).

Thanks again for the help! I’ll be back with charts sooner are later.

 

WOW!!! I LOVE that conversion and those seats are beautiful. I am going to hit you up on Instagram right now....

 

Thank you. I’ve wanted to build this van for several years, and, I’ve been in process on it for almost two already. It’s really a “dream rig” for me, and it’s really exciting to have it far along enough to actually get out and drive it a little while I’m finishing it up.