Injector O Ring question
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Injector O Ring question
Since I bought my truck I've been planning on replacing the injector O rings. During the summer it would always puff some blue smoke at startup, and as it gets colder it's harder to start and blows more blue when it starts. Also seem like it looses oil pressure overnight, it takes some cranking before the injectors start firing.
Anyway, I read that when you have bad o rings, there will be oil in the filter bowl. Pulled that out today, and it was clean, nothing but diesel in there. Does this mean my o rings aren't in bad shape? Or can they be bad without leaking oil into the fuel?
Anyway, I read that when you have bad o rings, there will be oil in the filter bowl. Pulled that out today, and it was clean, nothing but diesel in there. Does this mean my o rings aren't in bad shape? Or can they be bad without leaking oil into the fuel?
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From: Hagerstown, MD
A fuel filter with a black tint or discoloration has been known to be a sign of bad injector O-rings as return fuel passing thru the bowl on its way back to the tank will have some oil mixed in. There wouldn't necessarily be oil physically in the bowl.
I could be wrong, but it just sounds like tired injectors to me overall. I'm not quite as wise as most on here about these types of problems however...
I could be wrong, but it just sounds like tired injectors to me overall. I'm not quite as wise as most on here about these types of problems however...
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From: Quaker Hill
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That's what mine looked like with bad o rings. The HP oil pressure is greater than fuel pressure, so the oil pushes by the o rings and gets into the fuel system. If you think your bleeding off pressure overnight, the next step would be to get a pressure reading somehow. I do not have any experience with that, but there are a bunch of reasons for not building pressure. Don't freak out thinking it's something big yet. Someone will chime in soon with more help. Do you have AE or something you can read your ICP and IPR with? Also, if your going to do your glow plugs, DO NOT use Autolites. You will regret it. Here's why, below. Good luck!
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[/IMG]That's what mine looked like with bad o rings. The HP oil pressure is greater than fuel pressure, so the oil pushes by the o rings and gets into the fuel system. If you think your bleeding off pressure overnight, the next step would be to get a pressure reading somehow. I do not have any experience with that, but there are a bunch of reasons for not building pressure. Don't freak out thinking it's something big yet. Someone will chime in soon with more help. Do you have AE or something you can read your ICP and IPR with? Also, if your going to do your glow plugs, DO NOT use Autolites. You will regret it. Here's why, below. Good luck!
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That's what mine looked like with bad o rings. The HP oil pressure is greater than fuel pressure, so the oil pushes by the o rings and gets into the fuel system. If you think your bleeding off pressure overnight, the next step would be to get a pressure reading somehow. I do not have any experience with that, but there are a bunch of reasons for not building pressure. Don't freak out thinking it's something big yet. Someone will chime in soon with more help. Do you have AE or something you can read your ICP and IPR with? Also, if your going to do your glow plugs, DO NOT use Autolites. You will regret it. Here's why, below. Good luck!
My CTS reads ICP and IPR, but I'll be honest, I'll have to do some research to figure out what is a good reading vs what is a bad reading.
And I made sure to order the Motorcraft glow plugs, though one of the reasons I haven't changed them out yet is I'm terrified that the ones in it could be Autolites that aren't going to agree with me when I go to pull them out.
Thanks for the reply!
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From: Carhenge
That's only a symptom of OBS powerstrokes that have a regulated return from the factory. Our fuel system is deadhead in the cylinder heads, unless it has been modified with a regulated return, FRx, or some other mod to relieve the deadhead fuel rails the black in the filter is not from engine oil leaking past injector o-rings.
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From: Quaker Hill
Clux, my truck that I showed the pic of is an 01. No aftermarket fuel lines, just bone stock except for my 6637, and GP led. Where would the oil residue in my filter have come from? There's not any other place in the engine where the 2 meet other than the injectors, right? Not arguing with you, just pursuing a higher 7.3 education...
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Post Fiend
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From: Carhenge
Clux, my truck that I showed the pic of is an 01. No aftermarket fuel lines, just bone stock except for my 6637, and GP led. Where would the oil residue in my filter have come from? There's not any other place in the engine where the 2 meet other than the injectors, right? Not arguing with you, just pursuing a higher 7.3 education...
Our stock fuel system is totally dead-head, with one way restrictors where the fuel line goes into the head. Once in the head, there is no path back to the fuel system.
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I'll have to pull the tune off my truck tomorrow and get some numbers. I monitor ICP all the time, and haven't noticed anything that concerned me. Around 450 at idle up to right around 3000 at WOT. I don't watch IPR much so I'll check it tomorrow and report back.
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From: Carhenge
Simple diagram of the stock fuel system.
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From: Gary,Indiana
This is the first I've heard of the restrictors in the fuel lines. I assumed the oil mixed in the head and then made it's way to the bowl when the engine was off or something.
I'll have to pull the tune off my truck tomorrow and get some numbers. I monitor ICP all the time, and haven't noticed anything that concerned me. Around 450 at idle up to right around 3000 at WOT. I don't watch IPR much so I'll check it tomorrow and report back.
I'll have to pull the tune off my truck tomorrow and get some numbers. I monitor ICP all the time, and haven't noticed anything that concerned me. Around 450 at idle up to right around 3000 at WOT. I don't watch IPR much so I'll check it tomorrow and report back.
So is your truck using oil? How many miles does it take you to use or burn 2qts. of oil?
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Just got back from a drive to get my ICP and IPR numbers.
Cold idle (50*EOT): ICP around 700, IPR 17-18%
Warm idle(180*EOT): ICP 450-500, IPR 11-12%
WOT: ICP 2400 max, IPR 38% max.
From my limited understanding of those numbers, IPR seems to be fine, and ICP doesn't seem to have any issues either, unless it's a bit low at WOT for the truck having a tune? Truck runs beautifully by the way, with plenty of power, so I have a hard time thinking the injectors are going south.
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From: Quaker Hill
Ok, my limited knowledge would make me think your ICP and IPR seem good. My flatbed with 230k on it was having trouble starting early this winter. I did GP's, injector o rings, and a GPR. Also, I later discovered my batts were weak. They tested ok, but the voltage dropped too low when GP's were on. Id test your GPR first. Then onto the GP's. If your afraid they're autolites and they're swollen, there's a way to ohm them out. At least you'd know if they're good. If they're all working, you can wait til you have a good time to deal with the possibility of autolites. Gp's will make a huge difference. In my case, my injector o rings helped a lot too. I'd do gp's and I rings at the same time. It's a lot easier to put your gp's in before your injectors, as long as you know your cylinders are completely empty of fluid.