How to bleed the lines on a 7.3 idi

The right way of bleeding injectors on a 7.3 IDI.
Have fun!
Edit:
For anyone who is looking at this video because they are having issues, a good resource is www.oilburners.net/forums/6-9... Good IDI forum, lots of advice. I'm on there as Macrobb.

[@dwightpr8541]

Wow i love idi because I don't have to deal with wiring and computers but this guy wiring is crazy

[@Huskinmatt]

Bro... holy smokes... I gotta step my wiring game up

[@demolitionbmxd]

Great video, thanks! Not new to bleeding out diesels but I am needing to do a 7.3 idi I recently picked up and not knowing these engines at all I wasn't sure the best way to do it on my own. This covered everything. Thanks again, much appreciated!

[@jamesbuck3818]

Same boat brother... mine is an 85 F350 originally w the 6.9. Now a doner 7.3

[@joeyfiniguerra3101]

God brother you're a g you got a nice glow plug on your gas that is a guide me right there I love it I appreciate the video thank you I got a old 7.3 l with no turbo the rainwater's been coming through the hood and the intake was slap full the whole motor was full of rain water I've been working on that baby for a minute and I had to do all the o-rings and injectors and I found your video I love it thank you bless you

[@mikesmith8952]

I hope you wrap up all those loose wires someday as you are just asking for a engine bay fire of epic proportions sir. The insulation will get rubbed away or short out to some metal and wala, fire.

[@bustsrods]

Wow!!! That's hot!!!! I need a wiring diagram to watch this!!!

[@marcusdevries3453]

who in the hell wired your truck it looks like a 5 year old got under the hood.

[@flintlocke7954]

🤣 what i said! Wire nuts bro?

[@kman-mi7su]

I thought he spilled a plate of spaghetti under the hood!

[@andrewfernandez3827]

THANK YOU SO MUCH!!

[@Cruiseomatic380]

What in the world is with all those wires?! But good instructional. Pretty clear and to the point.

[@MacRobbSimpson]

I ran new, individual wires to each glow plug(pink for driver's bank, green for passenger). Moved my controller to the passenger's side fender well. Also, a lot of the stock wiring has been pulled from it's sleeves and messed with more than once.

[@Cruiseomatic380]

Oh. I seen all the bare wiring and wire nuts everywhere and was amazed at it all lol. And here I thought my bay was a mess...

[@CJ-fw9iq]

excellent ,thankyou

[@rustedpig964]

If one pregnant silicone mite gets under that hood and hatches her brood, your truck will be toast.

[@ZakarooNetwork]

How did you rig the 9th Glow pug? That's Bad ass. I would like to light cigarettes like that.

[@wheelman5600]

I don't know how he did it but all I know is the glow plug needs 12 volts to turn cherry lol

[@FarmerDrew]

Wow your truck cranks fast

[@byPetra]

thank you

[@lorenzomendez9086]

do you know if the 90e350 7.3 motor that comes in the vans will fit in my f350 truck?

[@MacRobbSimpson]

More or less, yes. The long block is the same. The oil cooler is different, as are the exhaust manifolds. If you re-use your truck manifolds and oil cooler, you'll be fine. If you are just using it as-is, you might need to do some fabricating if you can't use the truck manifolds and oil cooler.

[@skn9895]

Good information. But damn! That camera work! I nearly got dizzy watching this...

[@woodysibley6835]

At the end of Video you said something about timing ??? Is this something that needs done after replacing the injections & Why ???

[@MacRobbSimpson]

Yes, very yes. Or after replacing the injection pump, or after about ~50-100K miles, for best results. In most cases, the adjustment is minor. Why? Because we are dealing with a hydraulic-mechanical system here. Every part has tolerances, and no two are exactly alike. Plus, things wear. Timing in an IDI is determined by plungers in the IP that squish a certain amount of fuel together until the pressure reaches the pop pressure of the injector. A lower pop pressure means that the IP doesn't have to squeeze as hard, so the fuel injects earlier. So, if you replace a worn injector with a pop pressure of, say, 1400 with a new one at 1800, the new one takes more work and time to inject, so you'll have retarded timing compared to the old ones. Also, over time, the IP wears as well, such that it can't build up the pressure quite as fast, resulting in the timing slowly going retarded. This is counteracted, somewhat, by the injectors wearing as well - as their pop pressure drops, the injector component of the timing goes more advanced, while the IP wears retarded. However, what I see, long term, is that the whole system wears retarded. Getting the timing right, or as close as possible results in more power, less smoke, easier starting and better fuel economy.

[@carlwood8498]

Your idi cranks fast. What kind of starter do you have and do you know what cranking speed you're getting?

[@MacRobbSimpson]

Just a standard IDI starter; nothing special. I get the same speed from the crummy denso-clone $100 ones off Ebay, as I do from the longer napa or other starters. The key, with all of these is that they need to be new/clean inside - carbon buildup and corrosion(or worn brushes) will really slow down a starter - I've 'reconditioned' more than one starter with some Scotchbrite on the commutator.

[@carlwood8498]

@@MacRobbSimpson Thanks, good to know. I pulled a glow plug on my engine and cranked the motor over for 5 seconds to count the chuffs out of the glow plug hole. I did that a couple of times and was getting about 7.5 or so chuffs out of the glow plug hole for every 5 seconds of cranking. That works out to about 180 RPM cranking speed. That's not really terrible but I think it could be better. I just finished chasing down and fixing all the air intrusion issues on my engine and have moved on to the glow plug system. I was getting a pretty large voltage drop across the 2 power wires that go from the starter relay to the GP controller relay so I replaced those wires and got a noticeable improvement in starting but I am still measuring what I think is too large a voltage drop across the wiring harness that goes from the GP controller shunt resistor to the glow plugs themselves. Fortunately, the bullet style electrical connectors that connect to the backs of the glow plugs are available on eBay so I bought a set. When they get here I will make a new wire harness to go from the output of the controller to the 8 glow plugs and hopefully that will take care of the GP system, then I can move on to the starting system. Other than testing my cranking speed I have tested the starting current with a current clamp and I get a starting current of 450 amps. That seems a little high to me but it's a big, high compression motor so maybe that's normal. I will test the voltage drop across that big power wire while the engine is cranking and probably pull the starter off and clean it and the terminals and see about opening it up to clean up the commutator and hopefully get the cranking speed up over 200 rpm. With winter coming I am trying to do what I can to get this engine to fire up without any excessive cranking. Thanks for the reply, your videos have been helpful.

[@jamesedwards8288]

have no fuel from pump to inject ors

[@moneypitautoperformance8983]

daffy ducks how too video on bleeding lines lol

[@kman-mi7su]

Hahaha!!

[@alextubbs7928]

The very first line you was working on has broke in my truck right at the tip. Know ehere I can get one or know of a way to fix it?

[@MacRobbSimpson]

Here's a question: Do you have the vibration dampeners(rubber/metal clamps) that go across the lines installed? Typically, breakage like that is from running with those removed. Most people(me included) didn't believe they were that important at first... That being said, at this point you need a new line. I'd check the local wrecking yard if you can. Otherwise, Ebay... but be warned, a new line could easily cost $50.

[@alextubbs7928]

I'm going to say no cause it's just an all metal line nothing on it. But according to my fiancee if I don't start driving it I have to sell it. I'll pay $50. I'm going to check on all that to make sure the other don't break. Thank you

[@MacRobbSimpson]

Alex Tubbs I'd google for "vibration dampeners 7.3 idi"; it'll show you what to look for. You really need the four vibration clamps on the lines, or you will break other ones over time(usually just a few K miles). They're cheap, though.

[@loganmick1]

Alex Tubbs I had the #2 line break as well. mine didn't have the vibration dampeners. You can get the clamps at thedieselstore.com/injector-line-clamp-4-line-assy-for-1983-1994-7-3l-idi-6-9l-ford-diesel.html?gclid=CjwKEAjw3sKpBRDJ7rDqzsyuhDASJACZAikizKvW_HnT8ttsuVKWI4FW16N1FVL8hSW_1UwzM5ZoAhoCgiDw_wcB . You can go to accuratediesel.com to get a whole set of injector lines. I wouldn't advise going to a wrecking yard. I just needed the one line so I just ordered one from the local Ford dealership. It was like $100 or so for just the #2. hope this helps.

[@jmax857]

Holy hell what a combobulation of wires

[@MacRobbSimpson]

Yup! It becomes one of those things where after the first dozen times of unwrapping and re-wrapping the darned wires you just stop caring. One day I might do it more professionally, but it depends on having time & money to do it right.

[@jmax857]

Okay. What's your excuse for the alligator clips and wire nuts lol

[@jmax857]

Done right you shouldn't have to unwrap it anyway. Do it once do it right.

[@MacRobbSimpson]

Alligator clips - I'd have to watch it again, but IIRC I just used them for the vacuum pump. Which I wasn't able to get a pigtail for. And it kept working reliably, so... Wire nuts, well, I actually prefer them to crimp connectors(butt-splices and the like). I've had multiple crimp connectors pull apart on me; wirenuts tend to hold up longer and better. Also much easier to remove/redo when needed - Like the wires to the tach sender - The sender stays in the truck, and then I've got factory wires AND a custom tach wire attached. Could have been done with a decent plug connector, but eh... Typically, these wires don't cause me trouble. The only thing that *has* caused me issues is having a (cheap)female spade connector come off the FSS connector on the IP.

[@kman-mi7su]

I think I have air in my fuel lines as well. I had to start it a couple of weeks ago with some ether because my glow plug controller went bad. I fired it up and she sputtered a bit and then I heard a hissing sound while it was running. I got busy with my job and didn't need the truck for anything so I let it sit until I could get to it. Now she won't fire up and run even with ether she kinda starts and dies right out an I can still hear a sucking sound. Gonna try this when the weather gets a bit warmer and it stops with the every other day freezing rain here. I'm working outside in my driveway so I'm at the mercy of the weather.

[@mikemoravec760]

All I did was turned the key and after the 5th try fired up not kidding

[@coorsky3508]

You do know that there is a fuel return line that connects all of the injectors; and that you only need to bleed number eight?

[@MacRobbSimpson]

Not sure where you got that information, but it's plain wrong. The fuel return lines only carry a tiny amount of fuel from the injectors, just what leaks internally. It's not like a common rail injector where some fuel is returned intentionally. So, to bleed the pressure side of things, you need to bleed all the lines(or at least enough of them to get it to run).

[@rorymunroe3771]

Put a primer bulb on the fuel line like for outboard motor saves your starter and batteries mount low on pass side of mtr up near front where you can reach it crack inj's pump bulb tighten inj's and start...bulb has arrow on it for fuel direction...

[@MacRobbSimpson]

This only works to prime fuel up to the IP. It won't prime /through/ the IP, or prime the high pressure lines. Why? Because A, the IP has an sliding-vane pump inside it, a positive displacement pump. Without the engine turning over, this positive displacement pump won't turn, thus it will dead-head any fuel that attempts to go through it. B. Even if you got fuel past that pump, it would need to be at over 500 PSI to go down an injector line - Each of the 8 output ports have an internal check-ball that prevents fuel pressure from draining when it's not actively injecting. The injector itself needs 1400-1800 PSI to actually inject, so the fuel in the line is trapped, until the IP is ready to fire that cylinder.

[@robertatwood2503]

I'm not real sure about what the problem is with these engines I've got a 7-3 IDI I've ran this thing out of fuel like 10 times. with electrical shorts because my fuel gauge doesn't read accurately when I did my injectors I also replace the tappet cover gaskets it crank for about a minute then fired right up I just put bullet fuel rails on in which again I had to remove 90% of the injection and it crank no problem

[@MacRobbSimpson]

If you don't pull the injector lines(leave them attached to the IP), you don't really need to bleed it. The amount of fuel that will leak out is minimal. If the lines get completely drained(if you remove them they will drain fairly quickly), yes you will need to bleed it. Return side doesn't matter. If you run it out of fuel and then switch tanks, typically you haven't drained all the lines or anything, so it doesn't take too much to re-prime it. No manual bleeding needed.

[@finsamswin1875]

Robert Atwood yeah idk some are some aint

[@charlesflaco5037]

Is your truck manual??

[@MacRobbSimpson]

Yes. This one is, and most of them are. I only have one C6 truck(works) and one E4OD parts truck(trans solenoid connector broken; doesn't shift). 5-speeds are nice. Best transmission you could get behind an IDI; only issue is with the stock dual-mass flywheel that needs to be swapped to a LuK single-mass at first sign of slippage.

[@charlesflaco5037]

@@MacRobbSimpson my is a 4 speed

[@MacRobbSimpson]

The T18 4-speeds are quite reliable and heavy duty, just no OD. As long as you have 3.55 or lower gearing, it's not too bad.

[@sgtotaku]

I have an old 6.9, and I have air in the lines from replacing a chunk of fuel line... now that I've seen this, hopefully I can get the ol rig running again...

[@MacRobbSimpson]

Yup; they aren't hard to work on or fix. She'll run if you get her fuel.

[@sgtotaku]

MacRobb Simpson she's running wonderfully now. turned out she also needed a new battery. I wish there were more videos on repairing these old idi's.

[@MacRobbSimpson]

Anything specific you are looking for?

[@sgtotaku]

wiring info is a big one im trying to learn. my 6.9's wires are a mess between the factory components and added stuff thats since been removed.

[@bradleyhughes6430]

Does it work like that if it runs out? I run out yesterday in my 89 and could not get it to fire back up. Looked like nascar being pulled around in a field trying to crank it back. Just had to pay $125 to get it hauled back here 11 miles away.

[@jazzlives]

These engines are notorious for return line leaks and they lose their prime all the effing time over night. If I had to bleed off individual lines every time like in this video it would be a daily pain. I just crank it 'til it starts, about 60 seconds, no need to bleed the lines. Hard on the starter but hey, I'm not the person who designed this engine that loses its prime all the time. I tried all the fixes with o rings, hoses, washers, etc and nothing works, it just sucks air every night.

[@MacRobbSimpson]

Multiple things: 1. This procedure is for when you pull the injector lines, typically when replacing the IP. If the lines are generally full of fuel(which they will be if you get air intrusion), cranking works fine. 2. Air intrusion: Stop thinking about the return system. It DOESN'T MATTER. Everyone talks about having to make sure the return system is sealed, or you'll get air intrusion etc. It's not that. The problem is that you don't have a good check valve on the fuel filter, or leak on that filter head. Originally, the return line from the fuel filter head had a small check valve in it. This meant that when you shut the engine off, that check valve seals and keeps the supply side(lift pump up to filter head) from draining back. That check valve has disintegrated by now. So it's not doing it's job. Now, you have three possible fixes: 1. Replace the lift pump. The lift pump has two check valves inside it as part of it's method of operation. If it's working, when you shut the engine off, the lift pump will keep fuel from going backwards and draining down. However, as these pumps age, those valves work less and less. 2. Add a separate check valve. You can get a stand-alone check valve and mount it to the inlet side of the fuel filter, at the fuel filter(highest point). This will keep fuel from draining down by creating a seal at that point. 3. Check/repair leaks in the fuel filter head. On the 7.3 style head, there is a "fuel heater" wire/plug coming out of the top. Where this terminal meets the plastic around it, and where that plastic goes into the aluminum filter head can leak. You can tear the filter head apart, remove the entire assembly, and plug that hole with a pipe-plug if you wish. You can also choose to delete the return line on the filter head. Deleting it will reduce drain-back issues, but may make it harder to re-prime if you run the truck totally out of fuel. Another thing that may be useful(if these fixes don't work), is to add a clear section of hose to the lift pump-filter head line. Watch for bubbles when running. If, after more than 30 seconds of running, you are still getting bubbles, you need to work backwards and fix whatever is leaking - could be the hose loop at the lift pump(though you should have replaced this with the lift pump), could be a pinhole between there and the tank switchover valve, could be the switchover valve itself, or could be an issue with a tank pickup or line from there to switchover valve. (You can check tank-side of valve by switching tanks and seeing if the issue goes away. If it's limited to one tank, you know it's pre-switchover valve(or valve itself). If it's both tanks, it's switchover valve or after).

[@jazzlives]

@@MacRobbSimpson Thanks very much MR, I'll see what I can do with your suggestions. Interestingly enough I was thinking about this and suspected that despite what many say, the return line piping is probably not to blame. Rather, it's all the lines leading to the fuel filter from as far back as the tank. I already replaced the heater plug o ring, I am probably tapping it for a brass plug next, also. I love this engine but damn this is a lot of work. Ford apparently made numerous changes to stop it over the years.

[@davidripley8109]

That looks like a rats nest of wires! Heat shrink, auto butt connectors & loom man!

[@jamesbuck3818]

R you for hire? WA. State....😁

[@mikesmith8952]

When using the starter solenoid to turn the engine over from under the hood without having a remote starter switch to attach to solenoid you will for sure want to use a screwdriver or some metal tool with an insulated handle of you will get zapped by the 12 volts from the dual batteries, wakes you up a bit but it does happen folks so beware! DO NOT use an un-insulated tool..

[@MacRobbSimpson]

12V isn't enough to do much. Unless you put it across your tongue. Remember, it doesn't matter how big the batteries are(or how many) - 12V is 12V. If your hands are sweaty, you might feel a little tingle if you are holding 12V. If they are dry, you won't notice it.

[@paulmaxwell8851]

Absolutely not true. Even with wet hands you cannot even begin to feel anything until you get up around 48V. And as MacRobb Simpson notes below, it doesn't matter if 100 12V batteries are wired in parallel; the output is still only 12V. I'm a former electrician.

[@MacRobbSimpson]

@@paulmaxwell8851 Erm, I've felt 12V multiple times. Usually when leaning across the engine compartment such that my arm is touching the positive battery terminal(or working on the alternator battery lead) with my other arm touching a thin edge of (grounded) metal. This *probably* wouldn't have happened if I'd, say, disconnected the battery any time I worked on the electrical system, but eh...

[@robertwood9572]

I tend to use a 20amp start button with some wire attached to either post, and then just leave it under the hood. I used to use a screwdriver or wrench or whatever but it would always slip off or get s bad connection. Also- you don't get zapped if you're not the ground. Electricity isn't magic. You can 100% cross the solenoid with a wrench and be fine.

[@skyhager5953]

@@robertwood9572 This guy gets it. I've never felt anything while using a wrench, electricity takes the path of least resistance. You barely get anything if you're not touching near the points.

[@wildmanindaet5612]

Ether? If you want to blow it up...

[@carterhalvorson9837]

Get that wiring cleaned up holy cow that looks terrible

[@samirashnar3906]

Bout sick of this damn truck man I give up

[@chriss4268]

7:51 hey I Could should you how to retime the injectors maybe in another video good luck trying to you son's ah bitchs 😂🤣😂

[@death6160]

God this sucks