GN and T-Type Performance Enthusiasts (GNTTYPE) Forums GN and T-Type Performance Enthusiasts (GNTTYPE) Forums
This is a general site search and does not include list archives.

Go Back   GN and T-Type Performance Enthusiasts (GNTTYPE) Forums > Technical Topics > Engine Electrical/Ignition

Reply
 
Thread Tools Display Modes
  #1  
Old 02-25-2012, 08:36 PM
Drs2288 Drs2288 is offline
 
Join Date: Feb 2012
Posts: 6
Drs2288 is on a distinguished road
Bang Head Need help! 84 GN

I purchased car a couple months ago and it was not running, bone stock. I messed with the cam sensor and it started running... Well I knocking off again and order Caspers cam sensor cap with the led light, have it set again and when I try to crank it I get an extremely loud back fire, I'm talking so loud a guy walking down the street dropped and screamed. Any ideas what it could be? It's really bothering me because I only have a couple weeks to enjoy it before I start my new job out of state. Any help would really be appreciated.
Reply With Quote
  #2  
Old 02-26-2012, 10:16 AM
kenmosher's Avatar
kenmosher kenmosher is offline
Whoosh
 
Join Date: Aug 2004
Location: CO
Posts: 3,984
kenmosher is on a distinguished road
Default Re: Need help! 84 GN

I wonder if the cam sensor is set 180 degrees out. Easy to do. Car will run, but will do a lot of weird things like backfires and rough idle.
__________________
Ken Mosher
1987 GN original owner 650+ HP Black
2015 BMW 328xi XDrive wagon
2012 Volkswagen Tiguan (the Tig!) Night Blue Met (sold)
2006 Trailblazer SS Red Jewel Tint 395 HP AWD (sold)
2014 Silverado LTZ Crew 4WD
2012 Honda VFR 1200F Tahitian Blue (sold)
2015 BMW S1000R Racing Red
2013 Honda CBR500R Red (wife's bike)
2014 Triumph Bonneville T100
2003 Harley Davidson V Rod Anniversary Edition
Reply With Quote
  #3  
Old 02-26-2012, 01:17 PM
Drs2288 Drs2288 is offline
 
Join Date: Feb 2012
Posts: 6
Drs2288 is on a distinguished road
Default Re: Need help! 84 GN

Quote:
Originally Posted by kenmosher View Post
I wonder if the cam sensor is set 180 degrees out. Easy to do. Car will run, but will do a lot of weird things like backfires and rough idle.
Samething i was thinking but i made sure #1 (driver side closest to radiator) was at TDC. It won't start at all now just cranks then bam
, loud back fire.

On an 84 are these the correct cylinder #s?

6 5
4 3
2 1 ??
Reply With Quote
  #4  
Old 02-26-2012, 05:16 PM
Keller's Avatar
Keller Keller is offline
GNTTYPE Founder
 
Join Date: Jul 2004
Location: Missouri
Posts: 9,424
Keller is on a distinguished road
Lightbulb Re: Need help! 84 GN

That is correct.

Do you have the correct wires going to the correct plugs? If not, you could easily get misfires. The plugs fire in pairs across each coil, and one should always be firing during an exhaust stroke, and therefore not ignite anything.
__________________
Scott Keller - GNTTYPE Founder & Moderator
Reply With Quote
  #5  
Old 02-27-2012, 02:35 AM
Drs2288 Drs2288 is offline
 
Join Date: Feb 2012
Posts: 6
Drs2288 is on a distinguished road
Default Re: Need help! 84 GN

Quote:
Originally Posted by Keller View Post
That is correct.

Do you have the correct wires going to the correct plugs? If not, you could easily get misfires. The plugs fire in pairs across each coil, and one should always be firing during an exhaust stroke, and therefore not ignite anything.
I'm going off the numbers on the original coil pack, I also have an 87 module/coil pack with caspers conversion harness so I swapped them out and still does the same.
If you don't mind maybe i can explain Better on the phone I'll message anyone my number that can possibly help me out.
__________________
89 Mustang GT - couple of mods
84 GN - Bone stock
Reply With Quote
  #6  
Old 02-27-2012, 03:13 AM
Keller's Avatar
Keller Keller is offline
GNTTYPE Founder
 
Join Date: Jul 2004
Location: Missouri
Posts: 9,424
Keller is on a distinguished road
Lightbulb Re: Need help! 84 GN

Quick thought: The "numbers" will be displayed upside down on a 86-87 car. Perhaps you have the coil flipped, and thus have every plug in concert wire wrong. Save for the center pair, of course. Even if center two are connected to their opposite across the center coil, it won't matter.

Before you start flipping the coil, be sure that the engine fires #1 in time with the mark on the balancer. Just get a timing light and check it with all the wires connected and someone else cranking.

There have been cars where the crank sensor gets damaged from a backfire. And others that have the timing chain jump. A timing light will help tell the real story.
__________________
Scott Keller - GNTTYPE Founder & Moderator
Reply With Quote
  #7  
Old 02-27-2012, 01:45 PM
Drs2288 Drs2288 is offline
 
Join Date: Feb 2012
Posts: 6
Drs2288 is on a distinguished road
Default Re: Need help! 84 GN

Quote:
Originally Posted by Keller View Post
Quick thought: The "numbers" will be displayed upside down on a 86-87 car. Perhaps you have the coil flipped, and thus have every plug in concert wire wrong. Save for the center pair, of course. Even if center two are connected to their opposite across the center coil, it won't matter.

Before you start flipping the coil, be sure that the engine fires #1 in time with the mark on the balancer. Just get a timing light and check it with all the wires connected and someone else cranking.

There have been cars where the crank sensor gets damaged from a backfire. And others that have the timing chain jump. A timing light will help tell the real story.
Thank you For the info Keller, I'll pull out the timing light when I get home today.
__________________
89 Mustang GT - couple of mods
84 GN - Bone stock
Reply With Quote
  #8  
Old 02-27-2012, 08:31 PM
Drs2288 Drs2288 is offline
 
Join Date: Feb 2012
Posts: 6
Drs2288 is on a distinguished road
Default Re: Need help! 84 GN

I have it running now, I checked the timing and the timing mark it at 16 degrees. How would I adjust that?
__________________
89 Mustang GT - couple of mods
84 GN - Bone stock
Reply With Quote
  #9  
Old 02-27-2012, 11:37 PM
Keller's Avatar
Keller Keller is offline
GNTTYPE Founder
 
Join Date: Jul 2004
Location: Missouri
Posts: 9,424
Keller is on a distinguished road
Lightbulb Re: Need help! 84 GN

http://www.gnttype.org/techarea/ecms...ensor_FAQ.html

Think you are at the chip's timing map mercy now. Unless the crank reluctor or cam is off from the stock position.

If it is running, the cam sensor is either right or 180 degrees off. Incremental changes have more effect on fuel delivery than spark timing. Look at some of the other articles on the topic on the website.
__________________
Scott Keller - GNTTYPE Founder & Moderator
Reply With Quote
  #10  
Old 02-27-2012, 11:39 PM
Keller's Avatar
Keller Keller is offline
GNTTYPE Founder
 
Join Date: Jul 2004
Location: Missouri
Posts: 9,424
Keller is on a distinguished road
Question Re: Need help! 84 GN

Quote:
Originally Posted by Drs2288 View Post
I have it running now
What did you move or change?
__________________
Scott Keller - GNTTYPE Founder & Moderator
Reply With Quote
Reply

Bookmarks

Tags
back fire, cam sensor

Thread Tools
Display Modes

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
Forum Jump


All times are GMT -4. The time now is 05:34 PM.


This page maintained by: gnttype-webmaster@gnttype.org

The content, images, text and multimedia displayed and contributed by the members of the Grand National and T-Type Performance Enthusiasts Organization are Copyright ©1996-2005. No part, section, image, article or whole of this site may be reposted or redisplayed without permission of the author/contributor and/or the Grand National and T-Type Performance Enthusiasts Organization.

Powered by vBulletin® Version 3.7.3
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.