Jump to content

E7 400 low power


Anonymous

Recommended Posts

3 hours ago, fjh said:

So try turning the screw in on the fac under the little cap that screw determines where the fuel starts coming on it! Turn it in half to one turn and try it! Max 20 pounds boost is off by at least 8  psi you should be making 28 to 30 !

Are you talking about the star wheel or what some people call the “smoke screw” on the backside? I have the star wheel set pretty lightly but the I found the smoke screw was backed all the way out. I turned it in and started driving and adjusting until I ran out of time l. Seemed to have a little improvement. 

Link to comment
Share on other sites

2 hours ago, Anonymous said:

Are you talking about the star wheel or what some people call the “smoke screw” on the backside? I have the star wheel set pretty lightly but the I found the smoke screw was backed all the way out. I turned it in and started driving and adjusting until I ran out of time l. Seemed to have a little improvement. 

The little two screw cap on the back ! That determines where fuel starts coming on related to boost! It won’t likely give you the boost you’re after but will improve gidy up go !

Link to comment
Share on other sites

Had some time to tinker today. Here's what all I did. Loosened the afc all the way up. No difference. Tightened the "smoke screw" all the way in to push the afc to wide open and kinda bypass the afc was my thinking. No difference. Even pulled the pipe off the muffler elbow to make sure it wasn't plugged up somehow. No difference. Double checked the turbo for shaft play and to see if it had any oil in it only to find it clean and free of play. Guess I will make sure the timing is correct and if so I believe I need to send the pump back off and have it rechecked.   
 

Link to comment
Share on other sites

5 hours ago, Anonymous said:

Had some time to tinker today. Here's what all I did. Loosened the afc all the way up. No difference. Tightened the "smoke screw" all the way in to push the afc to wide open and kinda bypass the afc was my thinking. No difference. Even pulled the pipe off the muffler elbow to make sure it wasn't plugged up somehow. No difference. Double checked the turbo for shaft play and to see if it had any oil in it only to find it clean and free of play. Guess I will make sure the timing is correct and if so I believe I need to send the pump back off and have it rechecked.   
 

Sounds like the only plan now you done all you can do! Timing will not give you what you’re missing there! 

Link to comment
Share on other sites

Well curiosity got the best of me this morning.  I decided to take one more look at the turbo before I send the pump off. I removed it this time and really wanted to get a better look at the exhaust side. At first glance everything looked fine. But as I was on a phone call I was fidgeting spinning the compressor side when I noticed it had a drag for a split second then it released and spun freely. Kept on messing with it and it kept doing the same thing. I put some shop air to the exhaust side and it didn’t spin as free as it should. Would come to a stop as if it had a break applied to it. Then I removed the exhaust housing and found the carnage. New turbo should be here later this week. 

IMG_6598.jpeg

  • Like 1
  • Like 1
Link to comment
Share on other sites

I feel like an idiot for it catching it earlier. And I also thought it should be smoking more. Guess it was getting just enough air to keep smoke down. Now I have to try and get the pump set back to where it was when I started. Will give a full report all is done. Thanks for all the help. 

Link to comment
Share on other sites

13 hours ago, Anonymous said:

I feel like an idiot for it catching it earlier. And I also thought it should be smoking more. Guess it was getting just enough air to keep smoke down. Now I have to try and get the pump set back to where it was when I started. Will give a full report all is done. Thanks for all the help. 

Naw just hold off till you get the turbo and see how it is ! Back the smoke screw out to its aprox location and tweak it so you got just a whisper of gray! And if you’re achieving about 28 to 30 psi boost your right as rain!😀Nice thing is you covered all the other bases!All good!

Link to comment
Share on other sites

We once had a truck that worked well for 6 months then wouldn’t pull  still under  warranty! We checked everything except the turbo! They wouldn’t let us change the turbo it was a vmac engine!after all the checks were done other than the turbo They put a top secret program in this truck and it layed down black smoke like no buddies business! Still didn’t pull ! They finally gave in and put him in a new truck! That said we all thought and still think a turbo would have cured the truck however water under the bridge! Would really like to know if the turbo would have cured this we never heard ! The truck was sold to a different person that didn’t know any better! All the evidence pointed to lack of air but know one would listen!

Link to comment
Share on other sites

11 hours ago, Anonymous said:

What a difference a new turbo makes. Got 25psi boost just driving not hooked to anything. Going to tweak the pump a little and try and get a little more out of it. 

pull some thing before you get carried away ! if you can get 28 to 32 is good numbers for a 400 ! A 454 will make 35 -37 . if you don't got a pyro get one! 

  • Like 2
Link to comment
Share on other sites

  • 1 month later...

Back at it!! So after some use with the new turbo I still fell like I'm short on power. For reference I hooked my lowboy to a friends freight liner with a wore out M11 in it and it ran much better than my truck. I have decided to send the pump back to the pump shop. So I pulled it off this morning and noticed the rack plug is stamped 2000. And from my younger days we used to take the "Mack rack plug" stamped 2095 and put them in our dodges so the pumps would go full rack. My question is did Mack use any other rack plugs other than the 2095 plug? I did talk to the previous owner of the truck and he had the pump rebuilt at some point and said it never ran as good as it did before they had it rebuilt. Im wondering if someone put the wrong plug back in the pump. 

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...