IDIBRONCO
IDIBRONCO
Your video did show that initial start.
Air intrusion on 1990 7.3L f350 with banks turbo
- Thread starter danda
- Start date
ok, I noticed it had been leaking a bit from under the fuel filter... not like a trickle or even noticeable drops now just idling, but enough that stuff underneath was all grimy from past use. So I figure air was getting in also. I couldn't tell if it was the water separator drain or the sensor. Anyway, I replaced with a wix 33617 filter and used the sensor from the original water sep housing and new o-ring. I filled the filter 50/50 with Lucas treatment and diesel. The tip of the sensor was quite corroded, and also the "water in fuel light" never comes on when the key is on before starting, so I'm guessing it isn't working anyway. It's a pricy little item and I'm not too concerned about WIF, so I guess I won't bother with replacing it now, maybe at next filter change. question: if I ground the wire that connects to sensor, should that make the "water in fuel" light glow, or what is proper way to test?
Engine started up and stayed running after just a couple secs cranking even though it had been sitting 24 hours and I just had the filter off. Then i drove it around a little and it would die any time I accelerate kinda hard and then sudden return to idle. Also, after I shut it off, it took 2-3 secs cranking to start. So I inspected... no fuel leak from the new filter, but anyway I tightened up the drain **** a bit more and heard the elec fuel pump lower pitch and bear down a bit more, so that tells me it was sucking in some air previously. After that, the engine stopped dying on sudden return to idle.
Will see if it starts up quickly in the morning or not. fingers crossed.
Also, the 2 new olives arrived today for the hard line between fuel filter housing and IP. If it starts right up, I guess I won't bother changing them, and just keep em on hand.
One worry... on the last start I didn't wait for WTS light to go out, and it cranked quite slowly, but still started. I realize this requires more amps, but still the batts should be ok I thought, but then I checked the alternator with multimeter and it's only putting out like 12.7v at idle. This makes me wonder if alternator is maybe going bad, as I was expecting more like 14. Hopefully voltage is just low cuz batts need charging.
Anyway, if it cranks slowly in the morning I will put charger on for a couple hours.
btw, With the wix 33617 filter, I don't see any way to attach the old drain hose+pipe, or really any kind of hose. Am I missing something? Anyway, f just removed them, which cleans engine bay up a little.
Engine started up and stayed running after just a couple secs cranking even though it had been sitting 24 hours and I just had the filter off. Then i drove it around a little and it would die any time I accelerate kinda hard and then sudden return to idle. Also, after I shut it off, it took 2-3 secs cranking to start. So I inspected... no fuel leak from the new filter, but anyway I tightened up the drain **** a bit more and heard the elec fuel pump lower pitch and bear down a bit more, so that tells me it was sucking in some air previously. After that, the engine stopped dying on sudden return to idle.
Will see if it starts up quickly in the morning or not. fingers crossed.
Also, the 2 new olives arrived today for the hard line between fuel filter housing and IP. If it starts right up, I guess I won't bother changing them, and just keep em on hand.
One worry... on the last start I didn't wait for WTS light to go out, and it cranked quite slowly, but still started. I realize this requires more amps, but still the batts should be ok I thought, but then I checked the alternator with multimeter and it's only putting out like 12.7v at idle. This makes me wonder if alternator is maybe going bad, as I was expecting more like 14. Hopefully voltage is just low cuz batts need charging.
Anyway, if it cranks slowly in the morning I will put charger on for a couple hours.
btw, With the wix 33617 filter, I don't see any way to attach the old drain hose+pipe, or really any kind of hose. Am I missing something? Anyway, f just removed them, which cleans engine bay up a little.
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IDIBRONCO
IDIBRONCO
The stock 1G alternators on these trucks are a pain to say the least. It will be more money, but if your alternator is going bad, then I suggest doing a 3G alternator upgrade. The 3G alternators are the ones that came out on the 93/94 (for example) trucks. It involves a little bit of wiring, but you get a better charging, more reliable alternator. I don't regret doing the swap to my Blue Truck and I haven't heard of anyone else who has after doing the swap to their truck.
This sounds like you are sucking in air before the electric pump.
No There's not a place to attach that hose on the one piece filters.
update. I tried some more things.
1. installed new olives in the hardline between fuel filter outlet and IP inlet. One of the old ones was a bit corroded. Also, I noticed that the hard line exterior is a bit pitted on the end with corroded olive. I'm not sure if that is important or not. anyway, replacing the olives did not fix the hard start after sitting.
today:
2. removed low fuel pressure sensor and put a plug in its place.
3. traced feed and return lines beneath vehicle. There is a hose descending from engine area that meets (plastic?) return hardline. This hose had no clamp and seemed a bit loose, so I added one. Strangely, though I could loosen this hose, I couldn't seem to remove it, so I'm wondering if maybe it is just a jacket around interior hardline. maybe that's factory? Didn't see any obvious fuel leak in either the feed or return line.
4. observed that exhaust has a rich fuel smell, and is somewhat visible. makes me think injector(s) are faulty. or could it be IP timing?
5. I cracked each injector at idle and observed engine change speed. Though during this process I found the rear injector passenger side was loose and spurting fuel. This was because previously I couldn't get it to seal well, and had stuck an o-ring between the injector nut and return cap. Well, that had worked for a while, but not long apparently. So today I put new viton o-rings under the cap w white grease, and it again was leaking a bit. So I put a washer between injector nut and return cap. That 99.9% fixes it, but still I see a little liquid start to seep out the top of injector nut a few seconds after wiping with a rag while idling.
6. Unplugged fuel line from elec pump inlet and ran a hose into a jerry can of diesel. Started the truck, shut-off, then let it sit about two hours. Upon restart, it sputtered a bit, which doesn't give me much faith. Anyway, I will see if its starts quickly in the morning but not holding my breath.
I'm thinking that the fuel-in-exhaust issue is probably distinct from the hard-start after sitting issue.
So at this point the fuel filter housing situation is:
* injector return line port: plugged
* fuel pressure sensor port: plugged
* fuel filter: replaced with 33617
* water in fuel sensor: original, threaded into 33617, not leaking fuel.
* filter heater: original, not leaking any fuel.
* shrader valve: original, not leaking any fuel.
My logic is that if air is getting IN somewhere, eg at the filter heater while sitting, then fuel must be exiting to allow the air in. So I must have a leak somewhere....
I'm also considering swapping the injectors as these haven't been changed since I bought the truck used 20 years ago... though I've only put maybe 10k miles on it in that time.
1. installed new olives in the hardline between fuel filter outlet and IP inlet. One of the old ones was a bit corroded. Also, I noticed that the hard line exterior is a bit pitted on the end with corroded olive. I'm not sure if that is important or not. anyway, replacing the olives did not fix the hard start after sitting.
today:
2. removed low fuel pressure sensor and put a plug in its place.
3. traced feed and return lines beneath vehicle. There is a hose descending from engine area that meets (plastic?) return hardline. This hose had no clamp and seemed a bit loose, so I added one. Strangely, though I could loosen this hose, I couldn't seem to remove it, so I'm wondering if maybe it is just a jacket around interior hardline. maybe that's factory? Didn't see any obvious fuel leak in either the feed or return line.
4. observed that exhaust has a rich fuel smell, and is somewhat visible. makes me think injector(s) are faulty. or could it be IP timing?
5. I cracked each injector at idle and observed engine change speed. Though during this process I found the rear injector passenger side was loose and spurting fuel. This was because previously I couldn't get it to seal well, and had stuck an o-ring between the injector nut and return cap. Well, that had worked for a while, but not long apparently. So today I put new viton o-rings under the cap w white grease, and it again was leaking a bit. So I put a washer between injector nut and return cap. That 99.9% fixes it, but still I see a little liquid start to seep out the top of injector nut a few seconds after wiping with a rag while idling.
6. Unplugged fuel line from elec pump inlet and ran a hose into a jerry can of diesel. Started the truck, shut-off, then let it sit about two hours. Upon restart, it sputtered a bit, which doesn't give me much faith. Anyway, I will see if its starts quickly in the morning but not holding my breath.
I'm thinking that the fuel-in-exhaust issue is probably distinct from the hard-start after sitting issue.
So at this point the fuel filter housing situation is:
* injector return line port: plugged
* fuel pressure sensor port: plugged
* fuel filter: replaced with 33617
* water in fuel sensor: original, threaded into 33617, not leaking fuel.
* filter heater: original, not leaking any fuel.
* shrader valve: original, not leaking any fuel.
My logic is that if air is getting IN somewhere, eg at the filter heater while sitting, then fuel must be exiting to allow the air in. So I must have a leak somewhere....
I'm also considering swapping the injectors as these haven't been changed since I bought the truck used 20 years ago... though I've only put maybe 10k miles on it in that time.
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TNBrett
Full Access Member
I’d try a new return cap on the one that’s still leaking. That’s the most obvious place to focus your efforts at this point.
Farmer Rock
just a fella' without a 10mm socket
It kind of sounds like that rear passenger side injector/line, has stripped threads and isn't sealing correctly. That would definitely cause a miss like when you loosen an injector line while running, but that shouldn't give you drain back, because it's on the high pressure side. It would however suck air in.
Rock
Rock
a bit more on that rear injector... when I took the nut off I noticed the mating surface on the line jumped away from the injector about 1/8 in, as if the line is too long. I figured maybe they weren't mating properly and I couldn't seem to fix it by just moving the line, so I bent the line ever so slightly until they line up. This may have put the line at a slight angle to the injector, but the nut threads on fine... no resistance like if it was mis-threaded.
anyway, I am considering swapping that injector just to see if anything changes.
also, I have a washer between the nut and return cap right now. This may be preventing the nut from getting 100% tight. Now that its held the cap in place 72 hours, maybe I can remove the washer, tighten the nut, and the cap won't leak anymore..... hope springs eternal.
anyway, I am considering swapping that injector just to see if anything changes.
also, I have a washer between the nut and return cap right now. This may be preventing the nut from getting 100% tight. Now that its held the cap in place 72 hours, maybe I can remove the washer, tighten the nut, and the cap won't leak anymore..... hope springs eternal.
update.
Today I pulled the leaky #7 injector and replaced it with a reman stanadyne.
The old injector is a UK brand, so apparently it had been replaced at least once. Also I discovered that the top threads were a bit screwed, so it seems it had been mis-threaded in the past, which I think explains the leak. The copper washer came out with it.
I didn't observe carbon buildup in the bore, but brushed it out anyway.
I put in the new injector with anti-seize on main threads and some lithium grease on the orings. torqued to 35 pounds. I inspected return cap and ensured it is all smooth with no burrs that might damage an o-ring. Then I lightly lubed the inside with grease and it snapped on nicely, a good sign I thought.
I tried to thread on the injector line nut, but it appeared to be at slightly the wrong angle. I did NOT attempt to force it, but instead bent the line ever so slightly about halfway along its length, which resulted in the correct angle at the injector. After that, the nut threaded on perfectly by hand. re-attached return lines, bled 4 injectors, and she fired up.
Actually, she surprised me by firing up with 4 injectors cracked. Never had that happen before. I quickly shut it down, tightened and restarted.
The good news: the primary injector line nut isn't leaking at all.
The bad news: The return cap is leaking pretty good.
So then I tried:
1. wiggling return cap around in various positions, trying to release any strain. no joy.
2. placing a washer between nut and return cap. no joy. made the primary line nut leak a bit.
3. placing an oring between nut and return cap. no joy. fuel spurted out from oring area.
4. replacing return cap with another and also replacing o-rings (that came with reman injector) with brand new vitons. no joy.
5. re-positioning hoses to hopefully reduce/remove any strain. no joy.
It seems that no matter what I do, that damn return cap just wants to leak.
Frankly, I am getting super frustrated with this engine. I've been cursing the international engineers who designed this crazy return system. I've worked on various diesels on old farm equipment, including international, with no crazy plastic caps and hoses. Those old fuel systems easily go decades without problems.
So, what now? Any ideas?
I guess I am leaning towards the notion that the original (grey) caps seem better made than the new ones. If I could obtain a single one of those (corner) that might be worth a try. And/or maybe I just some bad/oversize caps.
question: Is it even possible to buy a single oem return cap somewhere?
There is also an issue of a bracket which holds the glow plug relays and it is in the path of the return line, so the line has to snake around it, which may be causing some pressure on the cap. Well, I would be more inclined to that being the cause except that I manually moved the cap all around to every which angle/pressure with engne running and nothing helped.
At this point I'm also afraid to touch any other injectors because it seems like voodoo to get them not to leak, and once one is not leaking it should never be touched or even looked at again.
Today I pulled the leaky #7 injector and replaced it with a reman stanadyne.
The old injector is a UK brand, so apparently it had been replaced at least once. Also I discovered that the top threads were a bit screwed, so it seems it had been mis-threaded in the past, which I think explains the leak. The copper washer came out with it.
I didn't observe carbon buildup in the bore, but brushed it out anyway.
I put in the new injector with anti-seize on main threads and some lithium grease on the orings. torqued to 35 pounds. I inspected return cap and ensured it is all smooth with no burrs that might damage an o-ring. Then I lightly lubed the inside with grease and it snapped on nicely, a good sign I thought.
I tried to thread on the injector line nut, but it appeared to be at slightly the wrong angle. I did NOT attempt to force it, but instead bent the line ever so slightly about halfway along its length, which resulted in the correct angle at the injector. After that, the nut threaded on perfectly by hand. re-attached return lines, bled 4 injectors, and she fired up.
Actually, she surprised me by firing up with 4 injectors cracked. Never had that happen before. I quickly shut it down, tightened and restarted.
The good news: the primary injector line nut isn't leaking at all.
The bad news: The return cap is leaking pretty good.
So then I tried:
1. wiggling return cap around in various positions, trying to release any strain. no joy.
2. placing a washer between nut and return cap. no joy. made the primary line nut leak a bit.
3. placing an oring between nut and return cap. no joy. fuel spurted out from oring area.
4. replacing return cap with another and also replacing o-rings (that came with reman injector) with brand new vitons. no joy.
5. re-positioning hoses to hopefully reduce/remove any strain. no joy.
It seems that no matter what I do, that damn return cap just wants to leak.
Frankly, I am getting super frustrated with this engine. I've been cursing the international engineers who designed this crazy return system. I've worked on various diesels on old farm equipment, including international, with no crazy plastic caps and hoses. Those old fuel systems easily go decades without problems.
So, what now? Any ideas?
I guess I am leaning towards the notion that the original (grey) caps seem better made than the new ones. If I could obtain a single one of those (corner) that might be worth a try. And/or maybe I just some bad/oversize caps.
question: Is it even possible to buy a single oem return cap somewhere?
There is also an issue of a bracket which holds the glow plug relays and it is in the path of the return line, so the line has to snake around it, which may be causing some pressure on the cap. Well, I would be more inclined to that being the cause except that I manually moved the cap all around to every which angle/pressure with engne running and nothing helped.
At this point I'm also afraid to touch any other injectors because it seems like voodoo to get them not to leak, and once one is not leaking it should never be touched or even looked at again.
Old Goat
Full Access Member
Your last line, no truer words spoken. I have said the same thing.
"At this point I'm also afraid to touch any other injectors because it seems like voodoo to get them not to leak, and once one is not leaking it should never be touched or even looked at again."
I agree this set up used on these 6.9/7.3 engines is a Micky Mouse set up compared to other Diesel engines I have come across.
I have had Mercedes Diesels 25 years, Bosch has a nipple on ea side of the Injector with a small return hose between ea Injector. Some time the hose will weep, and easy to swap in a new section....but never had them suck air and drain the fuel system.
When you remove a hard line off the Injector, if you remove the hold down vibration clamps, it might give you more wiggle room to the line w/o tweaking it.
Be sure to replace the clamps.
I have an old Injector Iam looking at, and wondering if it`s the quality control of the "O" Rings. They don`t fit tight enough to the body and or are not fat enough to seal inside the caps.
Justin at... https://idiperformane.com Use to have the Fuel return Rails made of aluminum. I don`t see them on his site now. but here is a picture of one of his engines with them installed.
There is Dregs Garage up in I think Montana that makes the Brass return caps, but are a bit pricy.
Here is his YT Vid.
The plastic caps in the return kits are probably all made in China and the quality is....?
Goat
"At this point I'm also afraid to touch any other injectors because it seems like voodoo to get them not to leak, and once one is not leaking it should never be touched or even looked at again."
I agree this set up used on these 6.9/7.3 engines is a Micky Mouse set up compared to other Diesel engines I have come across.
I have had Mercedes Diesels 25 years, Bosch has a nipple on ea side of the Injector with a small return hose between ea Injector. Some time the hose will weep, and easy to swap in a new section....but never had them suck air and drain the fuel system.
When you remove a hard line off the Injector, if you remove the hold down vibration clamps, it might give you more wiggle room to the line w/o tweaking it.
Be sure to replace the clamps.
I have an old Injector Iam looking at, and wondering if it`s the quality control of the "O" Rings. They don`t fit tight enough to the body and or are not fat enough to seal inside the caps.
Justin at... https://idiperformane.com Use to have the Fuel return Rails made of aluminum. I don`t see them on his site now. but here is a picture of one of his engines with them installed.
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There is Dregs Garage up in I think Montana that makes the Brass return caps, but are a bit pricy.
Here is his YT Vid.
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The plastic caps in the return kits are probably all made in China and the quality is....?
Goat
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Thanks Old Goat. It's good to co-miserate, like therapy for me. 
Those aluminum return rails look nice. I hadn't heard about that. Thx for the pics.
I did consider the brass caps, but as you say they are pricy and right now I only need one, but from what I can tell they were only sold in full sets, and also I saw a recent thread that says the owner hasn't been replying, at least to someone that tried to contact via youtube.
Instead I found a return kit on ebay that claims to be high quality and made in germany, not china. It has the original 6.9 style caps with the single flare, not the new style with larger ribbed fittings. I don't like the new style as it seems more likely to damage the hose when removing. Here's the kit:
About the only thing I haven't done is walk into a ford dealership and ask them for an o-ring and a cap. Maybe that should be my next attempt.
Those aluminum return rails look nice. I hadn't heard about that. Thx for the pics.
I did consider the brass caps, but as you say they are pricy and right now I only need one, but from what I can tell they were only sold in full sets, and also I saw a recent thread that says the owner hasn't been replying, at least to someone that tried to contact via youtube.
Instead I found a return kit on ebay that claims to be high quality and made in germany, not china. It has the original 6.9 style caps with the single flare, not the new style with larger ribbed fittings. I don't like the new style as it seems more likely to damage the hose when removing. Here's the kit:
6.9 7.3L IDI Diesel Injector Installation KIT 83-91 Fits Ford International | eBay
This kit includes FREE Trial!
www.ebay.com
yeah, I've wondered about that myself. They generally do seem a bit loose on the injector. But at this point I've tried (a) o-rings from previous return kit, (b) o-rings from a new-old-stock o-ring kit from the 80's I had sitting around, (c) brand new viton o-rings, (d) o-rings that came with (on) the reman injectors I got, and (e) more brand new vitons.
About the only thing I haven't done is walk into a ford dealership and ask them for an o-ring and a cap. Maybe that should be my next attempt.
I found the aluminum rails here for $260.
idiperformance.com
I like the look and the fact there are no hoses to go bad and leak.
otoh, I don't like that it becomes impossible to remove a single injector without removing the rail from all 4 injectors on that side. And right now I only have a single leaky cap to deal with. So if I were ready to spend that kind of money, I might lean towards the brass caps instead.
I'm curious if anyone reading this has tried either kit?
Billet Injector Fuel Return Rails | R&D IDI PERFORMANCE
Replaces the leak prone factory hose based return system with solid rails and includes Viton O-rings.
idiperformance.com
I like the look and the fact there are no hoses to go bad and leak.
otoh, I don't like that it becomes impossible to remove a single injector without removing the rail from all 4 injectors on that side. And right now I only have a single leaky cap to deal with. So if I were ready to spend that kind of money, I might lean towards the brass caps instead.
I'm curious if anyone reading this has tried either kit?
Farmer Rock
just a fella' without a 10mm socket
The problem I see with the rails, is that the o rings will still go bad, which kind of defeats the purpose of installing it. The brass caps seem like the best way to go if you have the extra cash. It always seems to be a bad cap or o ring, rather than a fuel line anyway.
Rock
Rock
The plastic caps seem to last forever. My RV had the originals when I got it in 2019. I swapped out a few for ones from my truck that got new ones in 2017 because some looked discolored and such. They've been on here for 3.5 years now and are fine. I carry the spare used caps and o-rings just in case because why not?
quickster
Full Access Member
On my 87 I have a cap that has been leaking since day 1. I replaced the cap and o rings, but it still leaks. The injector has a nick in it where the o rings are. But the fuel doesn't drain back, and my truck starts like a gasser. Looked at it today after I ran to the dump and it's wet as usual. Have you ever taken the fuel filter off and checked how full the filter was first thing in the morning? You could have an air leak someplace else. It's frustrating, but you'll get it.
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