Go Back  Offshoreonly.com > Technical > General Q & A
454 mag mpi lack of power?  Idles and revs fine, no miss >

454 mag mpi lack of power? Idles and revs fine, no miss

Notices

454 mag mpi lack of power? Idles and revs fine, no miss

Old 05-24-2015, 08:18 AM
  #21  
SB
Registered
iTrader: (1)
 
Join Date: Nov 2004
Location: On A Dirt Floor
Posts: 13,520
Received 3,091 Likes on 1,393 Posts
Default

Originally Posted by nailit
[ATTACH=CONFIG]541125[/ATTACH][ATTACH=CONFIG]541126[/ATTACH]

oh, and rotors looked different??

The P looked older?? the S looks like the diagram, So dont know if they even changed the rotor when they replaced the engine or just a different kind? Has only 1 contact and the S has 2?

[ATTACH=CONFIG]541128[/ATTACH][ATTACH=CONFIG]541127[/ATTACH]
Your S rotor is the common one.

http://www.amazon.com/ACDelco-D447-O...1XK9SJMYPHA7XW



SB is offline  
Old 05-24-2015, 08:24 AM
  #22  
Registered
 
Join Date: Sep 2014
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Default

What were the fuel pressure readings on both engines? I didn't see them posted, I apologize ahead of time if I missed them in a post.
C1000 is offline  
Old 05-24-2015, 08:39 AM
  #23  
Registered
Thread Starter
 
Join Date: Oct 2008
Location: Slidell, La.
Posts: 1,617
Received 1 Like on 1 Post
Default

Originally Posted by SB
The new one came like that, but it was blue... "sierra" brand.

C1000, I didnt post.. Never checked fuel pressure... Dont know how/ never did it before... How do I go about that, I assume, I will need a guage? I will google to see also...
nailit is offline  
Old 05-24-2015, 04:38 PM
  #24  
Registered
Thread Starter
 
Join Date: Oct 2008
Location: Slidell, La.
Posts: 1,617
Received 1 Like on 1 Post
Default

Originally Posted by C1000
What were the fuel pressure readings on both engines? I didn't see them posted, I apologize ahead of time if I missed them in a post.
Ok, I officially know how to test fuel pressure. both engines read 38 psi when keyed. P runs same at idle and when I bump it, it slightly dips to around 36psi..

Didnt do the S as I thought I read that was what it was supposed to be. (Not sure I'll ever use a fuel pressure guage again, but $45 later, I have one!)
nailit is offline  
Old 05-24-2015, 05:10 PM
  #25  
Registered
 
Join Date: Apr 2004
Location: Michigan
Posts: 1,268
Received 239 Likes on 92 Posts
Default

Originally Posted by nailit
Ok, I officially know how to test fuel pressure. both engines read 38 psi when keyed. P runs same at idle and when I bump it, it slightly dips to around 36psi..

Didnt do the S as I thought I read that was what it was supposed to be. (Not sure I'll ever use a fuel pressure guage again, but $45 later, I have one!)
Ok I would suggest to leave the gauge hooked up and see were the pressure goes when under a load, and at WOT. Possibly falls off at higher rpms? don't know if it is your problem but if the pressures are ok you can then rule it out! I also think that any tool is a good investment!
abones is offline  
Old 05-30-2015, 06:41 PM
  #26  
Registered
Thread Starter
 
Join Date: Oct 2008
Location: Slidell, La.
Posts: 1,617
Received 1 Like on 1 Post
Default

Originally Posted by abones
Ok I would suggest to leave the gauge hooked up and see were the pressure goes when under a load, and at WOT. Possibly falls off at higher rpms? don't know if it is your problem but if the pressures are ok you can then rule it out! I also think that any tool is a good investment!
Ok, I backed her down the launch and ran her. I filled the fuel filter 1/2 with seafoam.
She seemed to run better. I cranked up the S and pushed each throttle up to about 2500 and it seemed to have same throttle response. (in gear)

I had fuel guage hooked on P and she stayed steady at 38-40 for whatever I did. idle, throttle in Neutral and throttle in gear.

I will have to run her in the lake to see.. oh, I am getting a leak in bilge too... Just changed pivot pins so maybe I have a bellow leaking now.... oh well
nailit is offline  
Old 05-31-2015, 02:49 PM
  #27  
Registered
Thread Starter
 
Join Date: Oct 2008
Location: Slidell, La.
Posts: 1,617
Received 1 Like on 1 Post
Default

Well, I brought her back to launch to try to find leak.
Sons a b!Tch, its coming from the S side (where is was leaking from pin) last summer. Well, looks like it was also leaking from cable bellow!!! AAAAAHHHHHH!! I have these lil b!tches at my house. They took 3 weeks to come in when I was changing out both pivot pins!!

They looked good, so i didnt think they were leaking and put it back together as I was excited to get them back together and test steering slack..

WELL, I got back to the house and turned hard to P and trimmed up that side and some water came out the inner flex of the shift cable...

On good, note the S engine seems to be running better when I poured the coals to it on the launch! :-)
nailit is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.