Go Back  Offshoreonly.com > Technical > General Q & A
Pulling my hair out, engine misses at 4K... >

Pulling my hair out, engine misses at 4K...

Notices

Pulling my hair out, engine misses at 4K...

Thread Tools
 
Old 08-14-2007 | 08:45 PM
  #21  
Griff's Avatar
Charter Member # 55
25 Year Member
Charter Member
Super Moderators
 
Joined: Oct 2000
Posts: 20,272
Likes: 2,512
From: Omaha/LOTO
Default

I'm guessing weak/cracked valve spring(s) and they are getting worse.
Griff is offline  
Reply
Old 08-29-2007 | 10:15 AM
  #22  
Registered
 
Joined: May 2007
Posts: 66
Likes: 0
Default

Have you found the problem yet?
TAZMAN is offline  
Reply
Old 08-29-2007 | 07:06 PM
  #23  
Thread Starter
Registered
20 Year Member
 
Joined: Nov 2000
Posts: 1,418
Likes: 20
From: Westport, Kentucky
Default

No, but the situation has improved. Turns out one of the ignition modules I swapped in to replace the Crane box was faulty. Tried a V8-24 Module and it got better. Next up is the V8-20 off a HP 500. I may have got the rockers adjusted a smidge too tight. I suspect that may be where a few of my RPM have gone. Right now it runs clean up to 4800 and fails to build RPM past that. Boost is normal, compression and leakdown fine.
BadDog is offline  
Reply
Old 08-31-2007 | 10:27 AM
  #24  
Registered
 
Joined: May 2007
Posts: 66
Likes: 0
Default

Do you have the non-adjustable rockers? If so what torque did you use?

Funny thing after I started reading your string my Checkmate started do a similar thing. Maybe its bad ora. Going to work on my problem today. I hope it might be a loose wire somewhere.
TAZMAN is offline  
Reply
Old 08-31-2007 | 10:59 AM
  #25  
The Menace's Avatar
Registered
 
Joined: Nov 2002
Posts: 3,029
Likes: 2
From: Bonita Springs, Florida
Default

A cracked valve will do exactly what you have described. You will also not be able to get to full rpm.
The Menace is offline  
Reply
Old 09-10-2007 | 08:26 PM
  #26  
Registered
 
Joined: May 2007
Posts: 66
Likes: 0
Default

Here is what I did. Jumped directly from + Bat. to + Coil and solved problem. I figure long small gauge (old) wire all the way to dash and back to coil is sucking Vs/amps. Plan to put key relay near coil to solve problem. Will post results.
TAZMAN is offline  
Reply
Old 09-10-2007 | 08:40 PM
  #27  
Thread Starter
Registered
20 Year Member
 
Joined: Nov 2000
Posts: 1,418
Likes: 20
From: Westport, Kentucky
Default

I meant to update this. The HP 500 module solved my problem. Only minor issue left is a slight stumble when trimming at WOT. I am also pursuing the relay to activate clean 12V to coil. Might be a lot easier than running all new wire from harness to dash and back. Should have been built that way to start. If I go this route a blocking diode will be used across the relay coil.
http://www.bcae1.com/relays.htm
BadDog is offline  
Reply
Old 09-12-2007 | 08:53 AM
  #28  
Registered
 
Joined: May 2007
Posts: 66
Likes: 0
Default

Baddog,

Tell me about the blocking diode. What is it for and were does it go? I was just going to use the relay near the coil.

Followup: I used the ling in your above e-mail "I see" said the blind man.

I have two relays Hella and PIAA from off road light systems I used. They both have built in diodes and the Hella has a 10 amp fuse. These are way over kill but I have them and they should last.

Last edited by TAZMAN; 09-12-2007 at 09:19 AM. Reason: Follow up
TAZMAN is offline  
Reply
Old 09-12-2007 | 09:30 AM
  #29  
Registered
 
Joined: May 2007
Posts: 66
Likes: 0
Talking Rocket Science

Oh BTW "I" figured this out after several weeks of having this problem and wrapping wires, separating wires, replacing wires, cleaning contacts (Baddog you know the drill) I finally asked my dad about the problem. Who is an aeronautical engineer (rocket scientist) he said immediately jump from +bat to +coil, if the stumble goes away take the jumper off and install an ignition relay between the key and the coil near the coil.

Never be to proud to ask good ol' dad for help .

Hey baddog here's to solving the problem

Last edited by TAZMAN; 09-12-2007 at 09:32 AM.
TAZMAN is offline  
Reply
Old 09-12-2007 | 09:39 AM
  #30  
Registered
 
Joined: Jan 2004
Posts: 3,682
Likes: 4
From: Boca Raton, FL
Default

Have you hugged your Dad lately?
Edward R. Cozzi is offline  
Reply


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

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.