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E7 low power help!


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On 7/27/2023 at 12:16 PM, Joey Mack said:

I'm impressed that you found a Pro Link 9000.. that's what I cut my teeth on back in 2000...  

Yup me too ! I spent a lot of quality time with that dam thing! once your on to it and figure which drawers everthing are in its a snap to work with ! its a mighty fine unit! Unfortunately these days you need to be a puter programmer as well! The thing with the prolink is your  in your out in minutes Not pissing around  having to wait for shit to load so you can use it! And it stayed the same for the most part ! They kept moving stuff around in the Vmac soft ware! it was getting more and more frustrating to use!

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14 hours ago, Dtech said:

We are back on this project today I have a Question for you E7 Mack experts. We checked the valve lash using the procedure in the book, however we noticed that when the intake valve is fully open on a cylinder the Exhaust valve on the same cylinder has lots of lash! This means that Mack does not adjust lash on the base circle of the camshaft lobe or we are out of time. Has anyone with experience ever noticed this? Just to be clear if I turn the Crankshaft in the direction of rotation to the cylinder marked on the flywheel 1-6, for example, that lash is correct however if I keep rotating it to the next set to be adjusted, the lash becomes larger than 0.024 around in the .060 thousandths on that previously adjusted exhaust valve? It will keep that gap through out the intake stroke and comes back to the .024 right before TDC on the compression stroke.  Is this normal? I also noted that this only happens on the Exhaust valve the intake lash remains the same through out all stokes other than the  intake stroke of course The mechanic that built this motor told me he had installed a used Crankshaft.  He had to change the Crankshaft drive gear due to size deference, the new use crankshaft had a larger gear on it !!! so he swapped it with the original drive gear.  I did check crankshaft to camshaft timing using the book procedure it seem to be on the money, I also did notice that Valve overlap is happening on TDC. I also double checked flywheel to crankshaft timing by pulling the nozzle on #1 cylinder and confirmed  TDC #1 alines with TC mark on flywheel.  Thanks For your help  

That extra lash is for engine brake ignore this! Is the engine equipped with dyna tard ? all is good! Was the cam replaced? or new cam gear changed? 

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36 minutes ago, fjh said:

That extra lash is for engine brake ignore this! Is the engine equipped with dyna tard ? all is good! Was the cam replaced? or new cam gear changed? 

 so I re read the the post the cam was changed I noticed so I believe there was an offset cam key available for these (  Joe correct me if Im wrong) Was the original  key used!?

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Original Cam and Cam gear was used with the original key. This makes sense with the Engine brake, since the compression brake has no Injector rocker arm to be the slave it has to use another cylinders exhaust rocker arm. Yes it is a Dyna Tard. Thanks for clearing this up. Does anyone know if 26 psi at the Injection pump is enough fuel psi?  

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Yes I am using the turning tool in the flywheel housing, yes I am turning it the direction of rotation I am not having any trouble setting the lash or checking it.  I am going by the book always do. I was just confused my the increase in the lash that is not common in Diesels.  I am a 35 year diesel tech not my first rodeo lol. This E7 just has me scratching my head.  Does anyone know the answer to my fuel psi ? I need to rule it out Thanks

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I don't know fuel pressure off the top of my head. What year engine? I have many E-7 shop manuals in my shop at home, and may be able to get you a picture of the page. 

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Hat's off to you for lasting 35 years...  I burned out at 25 years..  Now I have a cushy city job, with my own truck, list of work to do, and a handheld radio..  and no one baby sit's me...  I am currently trying to be a driver trainer for my dept. We need CDL drivers.  

Edited by Joey Mack
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22 hours ago, Dtech said:

Original Cam and Cam gear was used with the original key. This makes sense with the Engine brake, since the compression brake has no Injector rocker arm to be the slave it has to use another cylinders exhaust rocker arm. Yes it is a Dyna Tard. Thanks for clearing this up. Does anyone know if 26 psi at the Injection pump is enough fuel psi?  

Taking the whole fac of is a bit of a pain as it has a tamper proof screw still doable however. . I would pull the 4 screws on the Fac and inspect diaphragm my self ! that way you get to see and understand what makes it tick! 😁 Your Good fuel pressure wise  ! (Actual personal experience talking here)  anything over 20 under load is fine it will pull !   15  will still pull ok but not great ! 10 not so much  think spec is 20 -35 !  If you take the little cap off the end of the fac dodad  there youll find a screw with a jam nut ! Loosen the jam nut turn the screw in (count the turns) crank it in two to three turns see if this changes your situation ! it will lay down some coal but this may tell us a little more about whats going on and will take some of the sluggishness out of your take offs! you can play with this a by tweeking the screw in little bit by little bit to get the desired lack of coal by turning it in 1/2 turn at a time! Taking the whole fac of is a bit of a pain as it has a tamper proof screw still doable however. Also the don't use the timing specs on that page as gospel  I beleive its a vmac spec your in the zone at 19 to 24 for your App in my opinion !!

Edit I see Joe posted the the spec page sorry my bad ! 19 min ! 🙄

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Thanks FJH for your advice, However I am a little loss on the FAC I know the older mechanical injection pumps had them. I can not find anything like that on this pump? It only has wires going into the back of it. It has no lines from the intake manifold to the injection pump. It also does not have a Boost psi sensor that I can find only intake air temp that is also the only sensor that is in the manifold. It does have an air line for the air compressor inlet but no leaks on it that I can find. 

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2 hours ago, Dtech said:

Thanks FJH for your advice, However I am a little loss on the FAC I know the older mechanical injection pumps had them. I can not find anything like that on this pump? It only has wires going into the back of it. It has no lines from the intake manifold to the injection pump. It also does not have a Boost psi sensor that I can find only intake air temp that is also the only sensor that is in the manifold. It does have an air line for the air compressor inlet but no leaks on it that I can find. 

Well My Bad I think I was looking at something and posting to another! you obviously have VMAC and joes posted the spec there that is the correct stuff except the HP which may change the timing! and Maybe the Cam key I don't remember! anyway I'm going to stop posting I think ! I'm getting tired of chewing on shoe leather and my foot is getting sore!🙃  Macpro or someone may have some answers here!

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Has anyone ever had a Ecm being the root cause of low power? I do not think it is the issue but maybe it is? I wish I had a test ECM or maybe I could sent it to someone and see how it ran on there truck? 

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