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Cylinder pressure out intake port


ChallengeDave

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the gear train on the front of an E-7 is pretty stout.. jumping time would have caused issues in all cyl's. and i would expect watery eye's on the mechanic that is standing in the raw fuel cloud trying to figure out what went wrong...  just sayin'

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5 minutes ago, Onyx610 said:

So v, what your saying is you think cylinder 1 is loading up? Or whatever cylinder it was.

My first thought was timing. Why else would the intake spit out compression?? Then thinking he may have a fuel issue. Injector leaking or something. He has ruled out sticky rockers. Someone mentioned a delivery valve also. 

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9 minutes ago, Vmac3 said:

My first thought was timing. Why else would the intake spit out compression?? Then thinking he may have a fuel issue. Injector leaking or something. He has ruled out sticky rockers. Someone mentioned a delivery valve also. 

Agreed, that pop is  the compression coming out the intake and pushing whatever exhaust is left in the cylinder out through it.  I’ve been thinking timing the whole time but I don’t know much about these and didn’t want to sound dumb, also I wasn’t sure how these could jump time. So honestly it’s coming down to an engine brake, injector, or something in the pump. Glad you’re back, I will watch the big dogs now. 

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2 minutes ago, Vmac3 said:

Thanks. I appreciate this site. Lots of learning from others experiences. 

Honestly that’s the best part. Regardless of skill level we all have been there done something and learned something someone hasn’t. 

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Hey all, thanks for chiming in. To add some info. Engine did this at idle cold, so I never felt the need to test drive since the issue was present. I thought as well about cam timing, but I would assume if that was the case, all other cylinders would present the same symptom. Didn't check the spring pressures on the head, since I don't have a method here to do that. That's what ill let the machine shop handle. I kept thinking of the jake as well. But while I had it at idle with the covers off, I couldn't at least visually see it partially activating. I did rebuild the jakes during the overhaul, didn't see anything unusual.  Couldn't hurt to dig into them while I'm waiting I suppose. 

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2 hours ago, ChallengeDave said:

Hey all, thanks for chiming in. To add some info. Engine did this at idle cold, so I never felt the need to test drive since the issue was present. I thought as well about cam timing, but I would assume if that was the case, all other cylinders would present the same symptom. Didn't check the spring pressures on the head, since I don't have a method here to do that. That's what ill let the machine shop handle. I kept thinking of the jake as well. But while I had it at idle with the covers off, I couldn't at least visually see it partially activating. I did rebuild the jakes during the overhaul, didn't see anything unusual.  Couldn't hurt to dig into them while I'm waiting I suppose. 

Just a long shot here ! The Jake depends on the action of another rocker! correct ? SO maybe the spool actuator stuck on cyl one and is not retracted enough this could explain it ! I don't remember if the actuator piston runs off an exhaust rocker or intake! Another thing I don't know how honest your machine shop guys are BUT!  If the machine shop missfired on something I don't think there going to admit it! Your going to get this head back  reassemble it and the engine will run just fine! AND We will never know what the issue is or was unless you find something on your end! We had a situation had heads rebuilt the guides failed with in weeks seized valves  blabla These people did not admit to any wrong doing would not come to the table on another total engine job ! gos to say  WE don't use these guys anymore !

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I bet you are right..  Myself,,,, In my mind was questioning how the truck ran good for 20,000 + miles, and now this?  A sticking celenoid could happen during that time frame. and I did ask about an overspeed on the engine, but since this doesnt have a VECU,  he cant find that info...  anyway,,,   you need to be on this thread...  jojo

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2 hours ago, Joey Mack said:

yes sir...  and the power leash engine brake in the ASET engines can do it when an oring fails under the celenoid..  

Wouldn't this hold an exhaust valve open though? He's spitting out the intake valves, that's the only thing that has me reluctant to think it's the engine brake.

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8 hours ago, Big R said:

If one selenium failed would it not effect two cylinders?

Three! My self ! I'm tapped out ! Can't speculate anymore going to have to be patient an see what unfolds here we will all know next week once Dave gets  the head back on and running! My prediction is it will  run perfect and we will never get to the bottom of the issue!  Hope I'm wrong! Hopefully  Dave will find  a smoking gun or the machine shop finds an issue and fesses up ! But don't count on it!

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ok,, I missed the part about blowing back through the intake, I just read back over the post..   and Mark is showing you pics of a great tool to own,,  any chance you checked compression before digging deep?  Just curious, and I am really out of ideas on this one..  Good luck to you.  Keep in touch..  jojo

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