Scan tool results

Old 09-11-2007, 09:26 PM
  #1  
Registered User
Thread Starter
 
Join Date: Jun 2006
Location: Saucier/Gulfport, MS
Posts: 497
Likes: 0
Received 0 Likes on 0 Posts
Default Scan tool results

I finally managed to get a scan tool on my 99 454 mag mpi....A quick run-down of what it has been doing all summer long.....Runs great most of the time, but other times, it will just fall off RPM's, (engine won't die). Then will struggle to get over 2000 RPM's. If I let it sit for a few mins, it will run fine...Things done so far...All new sensors, fuel pump, regulator, I've went thru the pick-up tube & vent, & a complete tune-up....Now the results.
Nothing definete, but one thing that was odd, the timing was all over the place. It would go from -5 to +18, it does this constantly, & regardless of the RPM's. I checked for a loose timing chain, by watching the rotor button while barring the engine over, that seems fine. I'm leaning towards the ignition module (distributer mounted)....Does this seem to be a good direction, or...once again, am I way off base???
rangerrick63 is offline  
Old 09-11-2007, 09:34 PM
  #2  
Registered
 
Join Date: May 2007
Location: Georgetown, TX
Posts: 1,272
Likes: 0
Received 0 Likes on 0 Posts
Default

What scan tool are you using?
Griswald is offline  
Old 09-11-2007, 09:57 PM
  #3  
Registered User
Thread Starter
 
Join Date: Jun 2006
Location: Saucier/Gulfport, MS
Posts: 497
Likes: 0
Received 0 Likes on 0 Posts
Default

I can't tell you more than this, the logo on the top of the tool was "Quicksilver". I had a mechanic run the scan, & he seems to think that the module is a good direction to go. He ran a pretty detailed scan & found nothing out of the norm, except the timing being all over the place.
I know from my personal experience with street rods, even a radical cam'd engine...the timing will smooth out when the RPM's go up (that is watching a timing light). So, I did find it quite odd, that the timing would never smooth out.
rangerrick63 is offline  
Old 09-11-2007, 10:19 PM
  #4  
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha
Posts: 17,488
Received 41 Likes on 28 Posts
Default

I would agree with the module being the next place to check.
Griff is offline  
Old 09-12-2007, 05:30 AM
  #5  
Registered User
Thread Starter
 
Join Date: Jun 2006
Location: Saucier/Gulfport, MS
Posts: 497
Likes: 0
Received 0 Likes on 0 Posts
Default

Thanks for the input, I'll be ordering one today.
rangerrick63 is offline  
Old 09-12-2007, 07:32 AM
  #6  
Registered
VIP Member
 
Join Date: Jan 2004
Location: Boca Raton, FL
Posts: 3,682
Likes: 0
Received 0 Likes on 0 Posts
Default

It is normal for the timing to be erratic at idle, it should smooth out as the RPMs increase. Spark control module could be bad or the ground is faulty.
Edward R. Cozzi is offline  
Old 09-12-2007, 07:46 AM
  #7  
Registered
 
JIMKID Motorsports's Avatar
 
Join Date: Mar 2001
Location: Livonia Mi Usa
Posts: 1,973
Likes: 0
Received 0 Likes on 0 Posts
Default

if that has a knock sensor the computor will put the timiing all over the place if the sensor is getting hit just a thought good luck
JIMKID Motorsports is offline  
Old 09-12-2007, 07:53 AM
  #8  
Registered User
Thread Starter
 
Join Date: Jun 2006
Location: Saucier/Gulfport, MS
Posts: 497
Likes: 0
Received 0 Likes on 0 Posts
Default

I did remove all the grounds & cleaned them real good. All were tight & I didn't find any corrision, but however, when I removed the module from the distributer, I noticed a white residue all over the mounting plate, & even under the module. I was able to wipe it off, just not sure if it was some sort of dielectric grease or corrision preventive. I do know that I should put the grease under the module, but should I also cover the entire mounting plate?
As for the knock sensor....It does have one, but the scan tool showed that there was no "signal" that was indicating a knock. So I would assume that the sensor is working correctly?
rangerrick63 is offline  
Old 09-12-2007, 08:24 AM
  #9  
Registered
 
Turbojack's Avatar
 
Join Date: Sep 2001
Location: Houston, TX, USA
Posts: 2,287
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Edward R. Cozzi View Post
It is normal for the timing to be erratic at idle, it should smooth out as the RPMs increase. Spark control module could be bad or the ground is faulty.
The ecm is moving timing all over the place to keep the motor's rpm constant. Since it is quicker to change the timming than to have the IAC change.
Turbojack is offline  
Old 09-12-2007, 08:54 AM
  #10  
Registered
 
Join Date: Oct 2000
Location: Sussex, WI
Posts: 543
Likes: 0
Received 0 Likes on 0 Posts
Default

to check the timing at idle you need to put the motor into timing mode, rinda has the tool that will do this, about 40 dollars.
RonS is offline  

Quick Reply: Scan tool results


OSO Sponsor
OSO Advertiser
OSO Advertiser

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.

OSO Advertiser