Finally got around to testing, and then replacing the glow plugs.. 4 stuck.

[MJGenay]

Hey guys, sorry to be a bother. Still having that issue with some very rough running upon startup after sitting for a while. I was hoping the o rings would've fixed that. I just want to make sure I'm chasing the correct ghost. That rattling and whatnot in the video above is usually air in the lines, correct? I'm not looking for a bad injector am I? Supposedly PO replaced them with remanufactured ones a year or so ago.

 

[hacked89]

X2 air intrusion is supply side

Incase this didn’t make sense, the return system is not your supply side. You can run the engine with no caps and o rings if you wanted to it would just be messy. Things that sound like a gas knock on this engine that then go away is usually supply side air intrusion. Other things that can make it sound knocky but not internal mechanical are timing way off, bad injector (this sounds a bit different than the air). A lifter that’s lazy but I wouldn’t describe it as a knock. A rod knock in the bottom end sounds like a deep knocking and a lifter sounds like a higher tapping in the top end.

Can you catch us up and summarize what troubleshooting and diagnostic steps you took so far?

 

[The_Josh_Bear]

Now that I see what you're talking about, you ain't kidding. That's rough.

Since it goes away after a while you know it's not permanent damage. If you drive it like that does it try to race away from you? Like a tiny bump on the pedal and the engine tries to run wide open. If so that's air intrusion. (I'm guessing not though.)

After that is maybe an injector leaking down or sticking open.
Or a collapsed lifter that eventually fills back up. I've never dealt with that yet.

 

[MJGenay]

Now that I see what you're talking about, you ain't kidding. That's rough.

Since it goes away after a while you know it's not permanent damage. If you drive it like that does it try to race away from you? Like a tiny bump on the pedal and the engine tries to run wide open. If so that's air intrusion. (I'm guessing not though.)

After that is maybe an injector leaking down or sticking open.
Or a collapsed lifter that eventually fills back up. I've never dealt with that yet.

There is a bit of surging if I try to drive it when it is doing that, but more of a lack of power than any uncontrollable acceleration. Like the surge is more like the engine slows than the engine takes off.

So far I've replaced the o rings on all of the injectors where the return caps were leaking, that dried all of that up. The only remaining one that might be an issue is the one directly under the fuel filter. That one had fuel and dust stuck to it (the return cap, the metal fuel line, etc.), kinda like fuel might've been spraying out there. I really doubt it is the o rings on the return line so I'm kinda lost. That injector has a metal piece above it, between the top of the injector and the metal fuel line nut, kinda confusing. I'll attach a photo. It is almost like a coupling but I have no idea why it would be there.

I don't think it is anything to do with the fuel filter or the housing, everything up there is dry.

Do I need to worry about running the truck? I'm worried I might be damaging it while this issue clears up as the truck warms up.

Incase this didn’t make sense, the return system is not your supply side. You can run the engine with no caps and o rings if you wanted to it would just be messy. Things that sound like a gas knock on this engine that then go away is usually supply side air intrusion. Other things that can make it sound knocky but not internal mechanical are timing way off, bad injector (this sounds a bit different than the air). A lifter that’s lazy but I wouldn’t describe it as a knock. A rod knock in the bottom end sounds like a deep knocking and a lifter sounds like a higher tapping in the top end.

Can you catch us up and summarize what troubleshooting and diagnostic steps you took so far?

Okay I assumed that since the fuel return goes back to the filter and back to the tank there could be air in the lines from the return side.

To be clear the roughness upon startup is greater the longer the truck has sat. For example, if it sits 6 hours and gets cold (I assume it is getting cold when it is 20 or so outside and it is sitting outside for 6 hours), it'll rattle a little. If it sits 24 hrs it'll rattle like it is falling apart. If it sits an hour or so, or maybe even a couple hours, I will have absolutely no rattle and it runs fine.

 

[hacked89]

There is a bit of surging if I try to drive it when it is doing that, but more of a lack of power than any uncontrollable acceleration. Like the surge is more like the engine slows than the engine takes off.

So far I've replaced the o rings on all of the injectors where the return caps were leaking, that dried all of that up. The only remaining one that might be an issue is the one directly under the fuel filter. That one had fuel and dust stuck to it (the return cap, the metal fuel line, etc.), kinda like fuel might've been spraying out there. I really doubt it is the o rings on the return line so I'm kinda lost. That injector has a metal piece above it, kinda confusing. I'll attach a photo.

Do I need to worry about running the truck? I'm worried I might be damaging it while this issue clears up as the truck warms up.


Okay I assumed that since the fuel return goes back to the filter and back to the tank there could be air in the lines from the return side.

To be clear the roughness upon startup is greater the longer the truck has sat. For example, if it sits 6 hours and gets cold (I assume it is getting cold when it is 20 or so outside and it is sitting outside for 6 hours), it'll rattle a little. If it sits 24 hrs it'll rattle like it is falling apart. If it sits an hour or so, or maybe even a couple hours, I will have absolutely no rattle and it runs fine.

How you describe it is why I agree with @IDIBRONCO that it sounds like your supply side fuel is falling back due to air intrusion. I know I’m repeating what was said but your supply side should be under slight vacuum so if you have air intrusion somewhere like in the filter head or components it’s going to let air in and go backwards. Then when you start it you are pulling air + fuel until it clears.

To address your other questions:
The metal adapter on the injector line behind the filter is for setting timing.

I’ve cut an FSV in half before and have sumped a tank Re running from front to back, I don’t see a case where your return and supply is going to be in closed loop feed air to each other.

 

[MJGenay]

How you describe it is why I agree with @IDIBRONCO that it sounds like your supply side fuel is falling back due to air intrusion. I know I’m repeating what was said but your supply side should be under slight vacuum so if you have air intrusion somewhere like in the filter head or components it’s going to let air in and go backwards. Then when you start it you are pulling air + fuel until it clears.

To address your other questions:
The metal adapter on the injector line behind the filter is for setting timing.

I’ve cut an FSV in half before and have sumped a tank Re running from front to back, I don’t see a case where your return and supply is going to be in closed loop feed air to each other.

Thank you for the reply. Okay. This sounds annoying but fixable. Replacing a lifter is more than I would be comfortable with or could afford to pay someone to do.

The last paragraph in your post I don't quite understand. What is "FSV"? What do you mean by "sumped a tank re running from front to back".

What am I looking for here? Should there be an evidence of where it is pulling air? Injector caps all seem tight (that one with the metal adaptor I tightened a little bit last night but it was already pretty snug). I could replace the fuel filter, I think it is around 15 months old so it is probably due even though I don't put many miles on this thing, potentially the seal is going bad?

 

[hacked89]

Thank you for the reply. Okay. This sounds annoying but fixable. Replacing a lifter is more than I would be comfortable with or could afford to pay someone to do.

The last paragraph in your post I don't quite understand. What is "FSV"? What do you mean by "sumped a tank re running from front to back".

What am I looking for here? Should there be an evidence of where it is pulling air? Injector caps all seem tight (that one with the metal adaptor I tightened a little bit last night but it was already pretty snug). I could replace the fuel filter, I think it is around 15 months old so it is probably due even though I don't put many miles on this thing, potentially the seal is going bad?

Part of what I said could be slightly controversial and generalized about the return system because depending on how you have it run if you have air in the return system and supply side is under vacuum like it should where it connects at the filter you asked about could cause an issue. Regardless you will want to fix the leaking cap at your injector line with the metal adapter on it.

My last paragraph I was just saying in general focus under the hood first. Fsv is fuel selector valve and I was saying it’s not part of your problem and I would say highly unlikely tank is part of your problem for reasons from last post.

Your last comment-
The injector lines don’t hold or put pressure on the caps. If you have a leaking cap still left you want to fix that first.

Then if you still have the issue I’ll take a pic on one of my trucks and point to the next areas you need to check.

 

[MJGenay]

Part of what I said could be slightly controversial and generalized about the return system because depending on how you have it run if you have air in the return system and supply side is under vacuum like it should where it connects at the filter you asked about could cause an issue. Regardless you will want to fix the leaking cap at your injector line with the metal adapter on it.

My last paragraph I was just saying in general focus under the hood first. Fsv is fuel selector valve and I was saying it’s not part of your problem and I would say highly unlikely tank is part of your problem for reasons from last post.

Your last comment-
The injector lines don’t hold or put pressure on the caps. If you have a leaking cap still left you want to fix that first.

Then if you still have the issue I’ll take a pic on one of my trucks and point to the next areas you need to check.

I'm pretty sure that leaking cap has been solved. I turned the truck on for 30 seconds and saw no evidence of fuel coming out. I'm going to go take it to town and back and see what happens. Assuming I still have a leak, any pointers on fixing that? I'm assuming there aren't any o rings in there so I'm not sure what the procedure would be for sealing it (again, assuming it still leaks).

 

[hacked89]

I’ll try to keep it high level to not trigger a big debate on whether the return system can cause air intrusion but there is suppose to be check valves on the filter return port I mentioned and the IP return port. That’s why the scenario that I said could potentially happen shouldn’t happen in theory. Also we will put really worn injectors aside.

I’d be testing with the filter head first. When it sits and you think it has air have someone crank it while depressing the shrader and see if you have air in the filters. The fuel heater o ring is common intrusion point. Trying to keep it easy and common things for you. We can speculate a lot.

 

[MJGenay]

I’ll try to keep it high level to not trigger a big debate on whether the return system can cause air intrusion but there is suppose to be check valves on the filter return port I mentioned and the IP return port. That’s why the scenario that I said could potentially happen shouldn’t happen in theory. Also we will put really worn injectors aside.

I’d be testing with the filter head first. When it sits and you think it has air have someone crank it while depressing the shrader and see if you have air in the filters. The fuel heater o ring is common intrusion point. Trying to keep it easy and common things for you. We can speculate a lot.

Okay, I'll give it a go tomorrow morning with the shrader after it sits. I didn't fix that leak at the injector under the filter, its damp again. So I'm going to open that up once the engine cools and see what I can discover. Can't get it any tighter. It is strange because it seems as though the leak is above the plastic fuel return.

Regarding the air intrusion at the filter housing; would there be any evidence of such? Should I be looking for dampness? Reason I ask is I've already been all over that, the lines leading to the fuel pump, and the lines from the fuel pump as far back as I can see them; I don't see any dampness on any of those either.

Where in Bucks are you if you don't mind me asking? I'm originally from Lehigh County, grew up there, still have family in Lehigh, Northhampton, Bucks, and Berks counties.

 

[hacked89]

Okay, I'll give it a go tomorrow morning with the shrader after it sits. I didn't fix that leak at the injector under the filter, its damp again. So I'm going to open that up once the engine cools and see what I can discover. Can't get it any tighter. It is strange because it seems as though the leak is above the plastic fuel return.

Regarding the air intrusion at the filter housing; would there be any evidence of such? Should I be looking for dampness? Reason I ask is I've already been all over that, the lines leading to the fuel pump, and the lines from the fuel pump as far back as I can see them; I don't see any dampness on any of those either.

Where in Bucks are you if you don't mind me asking? I'm originally from Lehigh County, grew up there, still have family in Lehigh, Northhampton, Bucks, and Berks counties.

Yep you’ll want to fix that and thats what I was sayin before, you aren’t tightening the return cap down that’s not how it works. The cap is pressed over the injector inlet body and your supply steel line shouldn’t be touching it. The o rings are what seals it.

And cool on PA. I grew up in the northeast and now I’m in the warmister area, I say that town because most people know the air base.

 

[IDIBRONCO]

If an upper o-ring is leaking, you will get fuel on top of the return cap. If an injector line is leaking at the nut, you will probably get fuel on top of the return cap and out the top of the nut.

 

[MJGenay]

If an upper o-ring is leaking, you will get fuel on top of the return cap. If an injector line is leaking at the nut, you will probably get fuel on top of the return cap and out the top of the nut.

I think it might've been leaking at the nut. Unknown, pulled it all apart, replaced O rings, put it back together, drove it to a job site, worked a few hours, just drove it back home. It stuttered a bit (very little) after I turned it on and started driving it back but that cleared up after about a minute, however, I'm going to guess that means I haven't fixed my issue. If y'all don't mind, I'd love to know some other places I should be looking. I've checked all around the filter, other injectors, fuel pump, IP, and I see no evidence of fuel leakage.

 

[MJGenay]

Yep you’ll want to fix that and thats what I was sayin before, you aren’t tightening the return cap down that’s not how it works. The cap is pressed over the injector inlet body and your supply steel line shouldn’t be touching it. The o rings are what seals it.

And cool on PA. I grew up in the northeast and now I’m in the warmister area, I say that town because most people know the air base.

Understood. I think, I hope, I have that fixed.

Yeah my grandparents used to shop at the PX at willow grove when I was younger.

 

[PossumTruck]

Wish I could delete this post, rather than just edit it.