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6.2L Diesel Engine Discuss the 6.2 GM diesel engine & associated components.


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Old 02-11-2020, 02:34 PM   #11 (permalink)
thetundrawolf
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Quote:
Originally Posted by legendman View Post
I would think you would be able to find the bad injector if when you pull it, it is wet with Diesel.
Legit point

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Old 02-11-2020, 08:41 PM   #12 (permalink)
thetundrawolf
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Hey, so I pulled every single injector and not a single one looked wet like it was leaking... And it was running yesterday...

I took my inspection mirror and looked under the IP... No leaks there, either...

What else could it be? What is causing air to enter into the return hose on the top of thew IP?

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Old 02-12-2020, 02:46 PM   #13 (permalink)
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Yesterday I also pulled one of the injectors apart to learn how they work, and rebuilding them is actually pretty easy, as far as nozzle replacement and wave washer replacement, there is a company that sells all of those things on line, I will buy the kit and replace those things. My question is, because of the super high compression, could combustion be forcing air into the injectors, and the bubble eventually making its way into the IP? Because it doesn't seem like the injectors are leaking, though maybe 5 showed a little wetness, it appeared from oil being burned rather than fuel? I could be wrong. I want to seal up the injectors and go from there.
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Old 02-13-2020, 02:24 PM   #14 (permalink)
Bigboytoys
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Dang, I didn’t answer back fast enough, won’t be an injector.

It’s IP and back air leak.

A leaky injector will only bleed off the fuel in it’s line and the truck start and run away a bit cause of all the extra fuel in that cylinder if it was hydro locked.
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Old Yesterday, 12:20 AM   #15 (permalink)
thetundrawolf
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Quote:
Originally Posted by Bigboytoys View Post
Dang, I didn’t answer back fast enough, won’t be an injector.

It’s IP and back air leak.

A leaky injector will only bleed off the fuel in it’s line and the truck start and run away a bit cause of all the extra fuel in that cylinder if it was hydro locked.

For the injector check I disconnected the output from the fuel pump and pumped about a quart of fuel into a clear jar... No bubbles

Will rebuild Injectors and get back to you.

Oh, also I notice more and more bubbles coming into the low pressure return line as it runs, and no bubbles when it's off, it seems to come from the injectors.

As I said new return lines, noticed zero fuel on or around Injectors.

Will advise as soon as injectors have been rebuilt.
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Old Today, 11:31 AM   #16 (permalink)
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You have to check from the injection pump back, every connection, every fuel line.
You won't see leaks because fuel is under suction and not pressure from the tanks to the injection pump.


That's why Bigboy's method of finding leaks is key, it actually pressurizes the system from the tank to the injection pump.


Fuel lines that look ok along the frame could actually be sucking air. They won''t show as leaks because they are not under pressure.


I would run one line from one tank to the inlet on the fuel pump and see what happens. If your clear line stays pretty full of fuel over night then you have narrowed down where the air leak is.
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Old Today, 11:36 AM   #17 (permalink)
legendman
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Also I wouldn't bother with trying to rebuild the injectors.
Without a pop tester or specialized equipment you won't really know if the injector is good.
We are talking about pressures measuring between 1500 and 2000 lbs.

These things
• Nozzle Opening Pressure
• Chatter
• Leakage
• Spray Pattern

Need to be checked to rule an injector good or bad.
I would start saving and just get a set of rebuilts when funds allow.
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Quote:
Originally Posted by Diaric View Post
What your saying happened, should never be able to happen.
Quote:
Originally Posted by smackzed View Post
I put a chevrolet tailgate on my last truck and it started acting like a girl...love me, need me, want me pay attention to me. Took it off and put the GMC back on (fixed the latch) and it went back to being the same old dirty bastard it used to be
~ Bob
1987 K20 5.7 TBI 700r4 np208
1990 C1500 5.7 700r4 Short stepside
1999 Chevrolet K2500 5.7L Auto
2006 Jetta TDI 5sp

Do yourself a favor and read the 6.2 Diesel Student Training Manual ... lots of good info...it's in PDF format located here >> PDF Manuals

Last edited by legendman; Today at 11:38 AM.
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