1982-1993 Mustang GT Registry - www.mustanggt.org
Dedicated to the documentation and preservation of
1982-1993 Mustang GT's
since 1994!!
Home | About Us | REGISTER your 1982-1993 Mustang GT!! | GT Registry Statistics | Info By Year | Reference Gallery
Forums | Classifieds | Interactive Decoders | Production Numbers | GT Articles | Factory Literature | Info Needed | Donations
This message board and web site has been made possible through donations from: List of Contributors THANK YOU!!!!   
1982-1993 Mustang GT Registry Message Board  

Welcome to the 1982-1993 Mustang GT Registry Message Board!!

We're glad you're here! You are currently viewing our boards as a guest which gives you limited access to view lists of topics, our GT Registry articles & information and access some of our other FREE features. By joining our community, you will have access to read and post topics, communicate privately with other members (PM), respond to polls, upload your own photos and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact support.

Go Back   1982-1993 Mustang GT Registry Message Board > General Tech > Modifications
Register FAQ Members List Referrals Calendar JavaChat Mark Forums Read
Info NEEDED!!REFERENCE GALLERY!!REGISTER your 1982-1993 Mustang GT!!GT Registry StatsInfo By YearAbout Us

Modifications Changes from the factory stock setup - performance and appearance. What to buy next? What works & what doesn't?

Reply
 
Thread Tools Display Modes
Old 07-10-2009, 03:54 PM   #1
Raven68
Member
 
Raven68's Avatar
 
Join Date: Apr 2007
Location: Bristol, UK
Posts: 93
Default Problem with MSD 6A Ignition module...?

Just got back to the UK last week from holiday in Florida with suitcase full of parts for the 89GT Fitted MSD distributor, MSD Coil and set the timing to 15btdc, already got MSD ignition wires, and the car runs great.

So we then wired in the MSD 6A ignition box..... engine is hard to start, smells of fuel, has a rough idle and won't tickover (unless given more throttle) and then dies after 30 seconds......... Disconnect it, car runs just fine..... Connect it back up.......... same problem every time......

A few Fox owners over here in the UK says they just fitted it as per instructions and it works fine straight out the box.

Plug gaps were re-set to 50 thou.

Does timing need re-setting or checking again? Do we need to re-set the ECU? The battery was disconnected whilst we fitted the 6A but not for long..........Any ideas guys?
__________________
Oxford White 1989 GT 5.0 mild cam, roller rockers, headman headers, side exit pipes, de-catted, de-smogged, racing clutch, 3.73 gearing, A/C eliminator, Steeda Tri-ax, Cobra grille insert, 17 x 8 Cobra R rims,45 profile tyres, Wilwood Superlite 6 big brake kit, Roll cage, rear seat delete, MM K Member, MM front lower arms, MM Coilover Koni shocks, MM caster camber plates, Hurst roll control, MSD Pro Billet distributor, MSD Streetfire Coil, FRPP ali rad
Raven68 is offline   Reply With Quote
Old 07-10-2009, 10:02 PM   #2
93 Wht GT
2009 Donating Member
 
93 Wht GT's Avatar
 
Join Date: Jun 2003
Location: San Jose, CA
Posts: 1,221
Default

The MSD 6A box is a plug 'n play item with the MSD wiring harness. I've had no problems with mine and it's been in my car since 1994. My timing was advanced months before and was not adjusted at all.

Could me a bad box, maybe? I'd return the box for another one just to rule it out.

Rick
93 Wht GT is offline   Reply With Quote
Old 07-11-2009, 02:14 AM   #3
Raven68
Member
 
Raven68's Avatar
 
Join Date: Apr 2007
Location: Bristol, UK
Posts: 93
Default

Quote:
Originally Posted by 93 Wht GT
The MSD 6A box is a plug 'n play item with the MSD wiring harness. I've had no problems with mine and it's been in my car since 1994. My timing was advanced months before and was not adjusted at all.

Could me a bad box, maybe? I'd return the box for another one just to rule it out.

Rick
Thanks Rick.... everyones says they just 'plugged and played'..... thats why this is so frustrating, and I wanna be sure we haven't missed some other obvious adjustment. Maybe I could check it out on my 67 mustang and see what happens..............

MMmm, I'm beginning to think its a bad box, so I've asked MSD for a return shipping number.
__________________
Oxford White 1989 GT 5.0 mild cam, roller rockers, headman headers, side exit pipes, de-catted, de-smogged, racing clutch, 3.73 gearing, A/C eliminator, Steeda Tri-ax, Cobra grille insert, 17 x 8 Cobra R rims,45 profile tyres, Wilwood Superlite 6 big brake kit, Roll cage, rear seat delete, MM K Member, MM front lower arms, MM Coilover Koni shocks, MM caster camber plates, Hurst roll control, MSD Pro Billet distributor, MSD Streetfire Coil, FRPP ali rad
Raven68 is offline   Reply With Quote
Old 07-11-2009, 08:56 AM   #4
DoDew87
Senior Member
 
DoDew87's Avatar
 
Join Date: Aug 2002
Location: Davenport, Ia. **QUAD CITIES**
Posts: 943
Smile

Could be a bad box, but it could be as simple as the problem I had with my 89 (the one in my avatar <-----)...story first! I had a 6AL on my Fox car. It wouldn't start up one day when I was out, so I had it towed home and started tinkering with the usual suspect parts there. After trying everything all the way to the ign. mod. on the distributor, the last thing I tried was the MSD box itself. Unplugged and t-harness bypassed, the damn thing would start. Stupid me, I remove the box and send it in for testing. Gets sent back, checked out okay. During re-install, when I went to screw the ground eyelet back into its hole, I noticed the metal around the hole was dingy, crappy and could stand to be cleaned up. Did that, too and guess what, she started right up. I guess long story short, check all your connections over VERY WELL first! It can possibly save you money and down-time...and a blow to your ego! I'm still recovering from that 10 years later!
__________________

Last edited by DoDew87; 07-11-2009 at 08:58 AM..
DoDew87 is offline   Reply With Quote
Old 07-11-2009, 03:25 PM   #5
Raven68
Member
 
Raven68's Avatar
 
Join Date: Apr 2007
Location: Bristol, UK
Posts: 93
Default

Yep, good point DoDew... we'll check out the new earthing point we made to the shock tower...

I think the unit is giving out a healthy spark though 'cos we forgot to reconnect the ignition wire from the coil to the distributor one time and the spark jumped about 2" to the nearest earth........... !!!!

It just seems as though the ECU has forgotten how to control the engine when the 6A is connected
__________________
Oxford White 1989 GT 5.0 mild cam, roller rockers, headman headers, side exit pipes, de-catted, de-smogged, racing clutch, 3.73 gearing, A/C eliminator, Steeda Tri-ax, Cobra grille insert, 17 x 8 Cobra R rims,45 profile tyres, Wilwood Superlite 6 big brake kit, Roll cage, rear seat delete, MM K Member, MM front lower arms, MM Coilover Koni shocks, MM caster camber plates, Hurst roll control, MSD Pro Billet distributor, MSD Streetfire Coil, FRPP ali rad
Raven68 is offline   Reply With Quote
Old 07-11-2009, 03:53 PM   #6
Raven68
Member
 
Raven68's Avatar
 
Join Date: Apr 2007
Location: Bristol, UK
Posts: 93
Default

By the way we've got the 6A wired as per the MSD instructions for a Ford TFI system - bottom half below - thats right ain't it..........?

__________________
Oxford White 1989 GT 5.0 mild cam, roller rockers, headman headers, side exit pipes, de-catted, de-smogged, racing clutch, 3.73 gearing, A/C eliminator, Steeda Tri-ax, Cobra grille insert, 17 x 8 Cobra R rims,45 profile tyres, Wilwood Superlite 6 big brake kit, Roll cage, rear seat delete, MM K Member, MM front lower arms, MM Coilover Koni shocks, MM caster camber plates, Hurst roll control, MSD Pro Billet distributor, MSD Streetfire Coil, FRPP ali rad
Raven68 is offline   Reply With Quote
Old 07-11-2009, 05:16 PM   #7
93 Wht GT
2009 Donating Member
 
93 Wht GT's Avatar
 
Join Date: Jun 2003
Location: San Jose, CA
Posts: 1,221
Default

There should be a wiring diagram that uses the MSD wiring harness that plugs in between the box and the ignition coil. I'm trying to remember all this by memory. It's been 15 years ago when I did this install.

Take a picture(s) of your install. Maybe we can point out something

Rick
93 Wht GT is offline   Reply With Quote
Old 07-11-2009, 05:25 PM   #8
Raven68
Member
 
Raven68's Avatar
 
Join Date: Apr 2007
Location: Bristol, UK
Posts: 93
Default

Quote:
Originally Posted by 93 Wht GT
There should be a wiring diagram that uses the MSD wiring harness that plugs in between the box and the ignition coil. I'm trying to remember all this by memory. It's been 15 years ago when I did this install.

Take a picture(s) of your install. Maybe we can point out something

Rick
Yep, you're right but the harness just does the same job of orange & black to the coil and red & white to the harness though..... Will see if we can get some pics after checking it all through again, but you can't six wires wrong

__________________
Oxford White 1989 GT 5.0 mild cam, roller rockers, headman headers, side exit pipes, de-catted, de-smogged, racing clutch, 3.73 gearing, A/C eliminator, Steeda Tri-ax, Cobra grille insert, 17 x 8 Cobra R rims,45 profile tyres, Wilwood Superlite 6 big brake kit, Roll cage, rear seat delete, MM K Member, MM front lower arms, MM Coilover Koni shocks, MM caster camber plates, Hurst roll control, MSD Pro Billet distributor, MSD Streetfire Coil, FRPP ali rad
Raven68 is offline   Reply With Quote
Old 07-11-2009, 05:36 PM   #9
skunk
2010 Donating Member
 
skunk's Avatar
 
Join Date: May 2008
Location: Massachusetts
Posts: 925
Default

I have been doing some reading on this since I don't have one but I was curious. alot of problems seem to be from bad grounds like DoDew87 stated and poor connections. make sure everything is tight and the grounds are good, it's a pretty simple system but most of the problems where this ( and bad boxes) also what you using for a 12V source.
__________________
1991 GT white/ Titanium. 5.0. mild H,C,I, built Astro T5, built 8.8 w 3.73s, FRPP 31spline termi diff, 31 splines axles, plenty of MMS stuff both suspension and braces, Bullitt springs& agx adjustables, Ford racing wheels, Dunlop star spec tires & plenty more stuff.

Her resto thread:
http://www.mustanggt.org/forums/showthread.php?t=51391

2011 Lincoln MKX elite

2008 Ford explorer EB

2000Ford contour. modded, dyno tunded



skunk is offline   Reply With Quote
Old 07-11-2009, 06:03 PM   #10
Raven68
Member
 
Raven68's Avatar
 
Join Date: Apr 2007
Location: Bristol, UK
Posts: 93
Default

Quote:
Originally Posted by skunk
........it's a pretty simple system but most of the problems are grounds ( and bad boxes) also what you using for a 12V source.
Battery in the boot with 50mm2 heavy duty positive and negative cables to the engine bay. Red to the solenoid and black to a new earthing point which also takes the engine earth cable. MSD is directly connected to the battery cables so its getting a direct 12v......
__________________
Oxford White 1989 GT 5.0 mild cam, roller rockers, headman headers, side exit pipes, de-catted, de-smogged, racing clutch, 3.73 gearing, A/C eliminator, Steeda Tri-ax, Cobra grille insert, 17 x 8 Cobra R rims,45 profile tyres, Wilwood Superlite 6 big brake kit, Roll cage, rear seat delete, MM K Member, MM front lower arms, MM Coilover Koni shocks, MM caster camber plates, Hurst roll control, MSD Pro Billet distributor, MSD Streetfire Coil, FRPP ali rad
Raven68 is offline   Reply With Quote
Old 07-11-2009, 07:36 PM   #11
skunk
2010 Donating Member
 
skunk's Avatar
 
Join Date: May 2008
Location: Massachusetts
Posts: 925
Default

sounds like you got all the bases covered, just do quick scan of the grounds if all checks out you probally got a bad box. best of luck!
__________________
1991 GT white/ Titanium. 5.0. mild H,C,I, built Astro T5, built 8.8 w 3.73s, FRPP 31spline termi diff, 31 splines axles, plenty of MMS stuff both suspension and braces, Bullitt springs& agx adjustables, Ford racing wheels, Dunlop star spec tires & plenty more stuff.

Her resto thread:
http://www.mustanggt.org/forums/showthread.php?t=51391

2011 Lincoln MKX elite

2008 Ford explorer EB

2000Ford contour. modded, dyno tunded



skunk is offline   Reply With Quote
Old 07-11-2009, 11:02 PM   #12
93 Wht GT
2009 Donating Member
 
93 Wht GT's Avatar
 
Join Date: Jun 2003
Location: San Jose, CA
Posts: 1,221
Default

Yup! The MSD p/n 8874 (wiring harness) is what I'm using.

Well, we'll help you get this figured out

Rick
93 Wht GT is offline   Reply With Quote
Old 07-11-2009, 11:23 PM   #13
phastphil
Senior Member
 
phastphil's Avatar
 
Join Date: Jun 2002
Location: Levittown, Pa
Posts: 1,041
Default

maybe the harness was put together incorrectly, ( I know not likely, but I've seen other manufacturing defects before) why not try wiring it without the supplied harness and see if that makes a difference.
phastphil is offline   Reply With Quote
Old 07-12-2009, 04:42 AM   #14
Raven68
Member
 
Raven68's Avatar
 
Join Date: Apr 2007
Location: Bristol, UK
Posts: 93
Default

Thanks guys - we're not using the harness so we know where all the wires are going OK and have double checked that... I have a doubt about the vehicle ground so we'll clean that up real good.

Also reading the instructions again last night for the 10th time they highlight an issue if two plug wires are run adjacent to each other in the firing order? Guess that would be plug wires 6 and 5? These can generate interference in each other. So we'll separate them far apart and see what happens as well. The very rough idle seems like its running on 6 or 7 cylinders so maybe adjacent wires are an issue? We've also got chromed metal wire separators so I wonder if they are causing cross interference - we'll remove them as well...get some plastic ones in due course maybe

Also bought a decent timing light yesterday so we'll doublecheck all that as well..

Keep any thoughts coming and I'll let you know the outcome for sure...
__________________
Oxford White 1989 GT 5.0 mild cam, roller rockers, headman headers, side exit pipes, de-catted, de-smogged, racing clutch, 3.73 gearing, A/C eliminator, Steeda Tri-ax, Cobra grille insert, 17 x 8 Cobra R rims,45 profile tyres, Wilwood Superlite 6 big brake kit, Roll cage, rear seat delete, MM K Member, MM front lower arms, MM Coilover Koni shocks, MM caster camber plates, Hurst roll control, MSD Pro Billet distributor, MSD Streetfire Coil, FRPP ali rad
Raven68 is offline   Reply With Quote
Old 07-12-2009, 10:42 AM   #15
Jerry: BLACK 85 GT h/b
Ambassador
2009 Donating Member
 
Jerry: BLACK 85 GT h/b's Avatar
 
Join Date: May 2002
Location: Winter Haven, FL
Posts: 9,106
Default

Those wire looms can be a problem. Sometimes they have to have a rubber grommet insulating the wire from the loom to prevent shorting to gorund.
__________________
Jerry: BLACK 85 h/b




To compel a man to subsidize with his taxes the propagation of ideas which he disbelieves and abhors is sinful and tyrannical. Thomas Jefferson
“The best government is that which governs least.”
variously attributed

A/R "Swirl" wheels
FRPP clutch/flywheel
subframe connectors
BBK catted H-Pipe
Flowmaster American Thunder exhaust
Edelbrock Performer Intake Manifold

Click HERE to REGISTER YOUR GT!
Jerry: BLACK 85 GT h/b is offline   Reply With Quote
Reply

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

| Home | Info by Year | Register A GT | Statistics | Resources |
| Classifieds |


All times are GMT -5. The time now is 03:04 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2022, vBulletin Solutions, Inc.