IT'S FIXED!!!! NO MORE AIR INTRUSION!!! FOR NOW
 

Macrobb was right the entire time. I replaced the fuel supply line and my truck drove like a top. Was a short test drive but she has cars to haul this Saturday. Here's a quick update. 94 f350 7.3 idi 4x4 was purchased for 450..Drove awhile then air intrusion started. Found many issues with fuel line. Holes. And bad repairs. The supply line isn't stock it has been changed my previous owner along with the injector pump so I was told

I replaced the check valve with clear return line to monitor air bubbles. I deleted the vacuum switch and SchaDer valve. Also deleted the fuel tank switch thingy under the truck. Only running rear tank. I dropped the fuel tank and found the fuel pickup strainer In pieces. I cut a v notch in submersible fuel line and wrapped steel mesh around it with a brass barb pushed into the hose so the clamp would clamp properly. Also changed fuel filter twice and did return kit with copper washers for injectors. Yes I used wheel bearing grease for orings. I've also notices my fuel filter light has been on but my fuel filter is aftermarket so I thought nothing of it. Well since I replaced the fuel supply line the truck runs great and no more fuel filter light. Also facet Dura-Lift e pump
​​​​​sorry for the long post but I'm excited she runs right again.

​​​​​​​also picked up steel lines and vibration clamps and steel return line that goes on top of the injector pump all for $75 at Junk yard. Thanks to all for the help with this beast. Hopefully she stays running properly

congrats on the fix ..

and good score on finding a jy idi to snatch some parts off of ..

they hardly ever turn up at the salvage yard here ..

Oh sure.. give mac all the credit lol. "Youre pumping air to the IP" is literally the first thing i suggested, but im just glad you got the thing running.

Hairybox you did help alot as well I just remember Marcobb repeating that air before ip but I appreciate all of yalls help

I live in a small town outside of Houston and 3 junk yards around me all had 7.3 idi. Most picked over tho. BuT in houston it's a kid in a candy store

I'm glad it ended up working!

psshha .. lucky dawg .. i see one every 2years and it's stripped by the time i get my hands on it ..

even raggly down broken FORD trucks bring 2k$ in nashville .. a chevy .. u can get for 500$ dollars but multiply x4 this is ford country and they're always in high demand .. rarely are they cheaper than what they bring for scrap so they rarely end up there ..

Just a follow up post. Yesterday she drove roughly 18 to 19hrs with maybe a hour or so break for fuel food etc etc. Only issue I had was I was going around a tanker and I had my foot in her hard. The battery light came on and the truck died while doing about 65 to 70ish. I pulled over on the shoulder and saw my radiator cap bubbling. Which it's done that before I need to replace it I went to the cab and my coolant temp gauge said 240. Which my truck was running 190 all day so I immediately thought I blew head gasket or something. Truck wouldn't start back up either. I found out my home made brace for my epump broke and the power wire shorted something out and blew my fuse to glow plugs. I swapped out the fuse and she fired right up. I checked coolant level and topped off maybe 1/4 gallon. I did see air bubble from my coolant filter housing so I closed my shut off valves to it. And she ran great the rest of the night coolant stayed 180 to 195. 200 the most but immediately back down to 180 while pulling about 5000lbs of car and engines. Today I drove her again with no issues at all. Perfect coolant temp. And I found out the a/c does work since the previous owner told me it didn't. So it was a good day. BUT BUT BUT she does idle a tad rough I'll change my fuel return line going to the tank and install my new steel lines and vibration clamps. But I do know I'm missing the small needle tip on the bottom of the injector for number 7.

So, this is actually typical. The water is at 190F, but the block is hotter(remember, the combustion temps are in the 1200+F range.
While you are driving, the water is heated by heat migrating it's way through the block, and cooled by the radiator. When you stop suddenly without letting it cool down first, you've stopped the water pump. The water in the block is at 190F, and you've got a /hot/ block and pistons to cool. So the heat migrates, and suddenly you hit 240+ and start to boil the coolant.

You can fix this by, you know, not going from WOT to off instantly. ;)

Give your truck a cooldown cycle(idling/less work) of a minute or so after pushing her hard, just to get all that extra heat through and out, and she'll appreciate it.

I have the aftermarket coolant temp kit installed on the passenger side block. But yes I do normally let it idle/relax before shutting her off. However the truck died and I didn't get a chance to do that haha

I am curious. The glow plug fuse blew. The engine was really hot. And a hot day but I tried to turn the engine on. And it didn't fire up. The wait to start wasn't on at all that's how I knew something was wrong with glow plugs. My question is shouldn't it have started since it was already hot?

also my glow plug controller is all stock. Could there be a issue with them staying on?

​​would this be a factor to the slight rough idle?

Probably heat soak. *every* injection pump will heat soak at /some/ temperature(worse if your injectors have a higher pop pressure).

I'm not sure what heat soak means haha

The rotor inside the IP delivers fuel to the head in which it spins through small ports. There is no seal between these parts, just the close tolerances of machining. When the IP gets hot, the head expands more than the rotor, widening the gap enough that fuel leaks out(into the body of the IP to be returned to the tank) instead of being injected.

This is what causes 'hot start' issues.

It usually becomes a problem when the engine is hot, you shut the engine off and try to start it 10 minutes later. If you start it up immediately, the engine heat won't 'soak' into the pump(which also has cool(er) fuel inside it). If you start it up after an hour or two, the pump/engine will have cooled down some.

The easy way to test for heat soak is when you crank when hot and it doesn't fire... slowly pour some cool water over the back of the IP, where the lines come out. If that's your problem, it'll fire right up.

I'll keep that in mind. I appreciate it