Click Here -> Please Consider Making a PayPal Contribution to the FordSix Forum!
2019 Contributors:
NJwpod, 1strodeo, mightynorseman, maxtrux, 6d7coupe, broncr, Phase3, 68Flareside240, bmbm40,
mustang6, WorldChampGramp, justintendo, BigBlue94, ags290, motorsickle1130, Rooster, ousooner919, ethanperry
rzcrisis, DoctorC, jamyers, Motorboy, fastpat, Silverback280, chad


<<< New Site Update >>>

Ignition woes

Moderator: Mod Squad

F-250 Restorer
Registered User
Posts: 703
Joined: Wed Jan 13, 2010 10:42 pm

Ignition woes

Post #1 by F-250 Restorer » Thu Sep 12, 2019 7:48 pm

Hey there. 1975 300, newly rebuilt with 8k miles. I was driving and engine just died at 40mph. No cough or stumble, just dead.

Ok, figured mad or stator pick up. Tested mad, but had intermittent power to keyed hot..battery
Showed same. New battery installed and got power to all systems. After testing coil, changed stator with dizzy in place. When I started it, I showed 20+ degrees advanced. Backed down timing. Idled great, but under power it backfires thru exhaust. Tried to change stator signal wheel to other roll pin position. Same. Idles great, pops under load.

Don,t know how to proceed.

F-250 Restorer
Registered User
Posts: 703
Joined: Wed Jan 13, 2010 10:42 pm

Re: Ignition woes

Post #2 by F-250 Restorer » Thu Sep 12, 2019 7:53 pm

Darn auto correct. Post was supposed to say MSD, not Mad.

pmuller9
Registered User
Posts: 3325
Joined: Tue Aug 06, 2013 12:33 am
Location: Columbus, Indiana

Re: Ignition woes

Post #3 by pmuller9 » Thu Sep 12, 2019 8:43 pm

The MSD ignition will carbon track the distributor cap if low resistance spiral wound plug wires aren't used.
This will cause cross firing under load and do engine damage.

Replace cap and rotor.

What are you using for plug wires?
Last edited by pmuller9 on Thu Sep 12, 2019 9:32 pm, edited 1 time in total.

User avatar
bubba22349
Global Moderator
Posts: 9091
Joined: Sun Jan 03, 2010 4:46 pm
Location: Flagstaff, Az. 86005 near the old Route 66

Re: Ignition woes

Post #4 by bubba22349 » Thu Sep 12, 2019 9:25 pm

Maybe a weak coil! Try doing a test reading of the primary and secondary windings with a Volt Ohm Meter. Good luck :thumbup: :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

pmuller9
Registered User
Posts: 3325
Joined: Tue Aug 06, 2013 12:33 am
Location: Columbus, Indiana

Re: Ignition woes

Post #5 by pmuller9 » Thu Sep 12, 2019 9:28 pm

No It is not a weak coil and if the engine continues to be run under this condition it will be damaged.

F-250 Restorer
Registered User
Posts: 703
Joined: Wed Jan 13, 2010 10:42 pm

Re: Ignition woes

Post #6 by F-250 Restorer » Thu Sep 12, 2019 9:41 pm

I am running $120 super duper msd wires.

pmuller9
Registered User
Posts: 3325
Joined: Tue Aug 06, 2013 12:33 am
Location: Columbus, Indiana

Re: Ignition woes

Post #7 by pmuller9 » Thu Sep 12, 2019 10:34 pm

Those are the right wires.
Measure the resistance of each wire. Should be around 50 ohms per foot.

Change the cap and rotor.

wallen7
Registered User
Posts: 204
Joined: Thu Jun 09, 2016 8:38 am

Re: Ignition woes

Post #8 by wallen7 » Fri Sep 13, 2019 9:49 am

I have run into cases with Duraspark that if the orange and purple wires are crossed in harness it will cause the timing to be off and and cause a backfire on acceleration.

F-250 Restorer
Registered User
Posts: 703
Joined: Wed Jan 13, 2010 10:42 pm

Re: Ignition woes

Post #9 by F-250 Restorer » Fri Sep 13, 2019 10:45 am

Wallen7: I believe I tried to swap the wires and it wouldn't start with them reversed. But I will look into it again. Thx.

Muller9: The cap, with brass contacts, is looking bad. I burn 3-4 caps a year. They love me at O'reiley's where I get new caps gratis, due to lifetime warranty. I don't believe the problem is due to the cap, but it is a good place to begin.

User avatar
MechRick
Registered User
Posts: 857
Joined: Wed Jan 04, 2012 7:43 pm
Location: Las Vegas, NV

Re: Ignition woes

Post #10 by MechRick » Fri Sep 13, 2019 11:41 am

If you installed the pickup *without* moving the distributor, and then had to move the distributor to get the timing back, the pickup wires are likely backward. The pickup pulse would be negative and the cap/rotor phasing way out, causing crossfire.
1994 F150, 4.9L/ZF 5 speed, C-Vic police driveshaft
EFI head w/mild port work, 3 angle valve job
1996 long block, stock pistons, ARP rod bolts
Stock cam, aluminum cam gear
Hedman header, full mandrel bent duals, crossover, super turbos
http://fordsix.com/forum/viewtopic.php?f=2&t=73244
Bronco II with a 2.3L swap http://fordsix.com/forum/viewtopic.php?f=13&t=72863
1988 F250 2x4, 460 ZF 5 speed.

pmuller9
Registered User
Posts: 3325
Joined: Tue Aug 06, 2013 12:33 am
Location: Columbus, Indiana

Re: Ignition woes

Post #11 by pmuller9 » Fri Sep 13, 2019 11:57 am

Somehow I missed the part about replacing the pickup coil.
In that case MechRick and wallen7 seven are correct.

When you get it running again get it timed back to 16 degrees, turn the engine off, turn the crank to 30 degrees and check the rotor position against the cap terminal like you did last time. (except it will be at 30 degrees instead of 20)

F-250 Restorer
Registered User
Posts: 703
Joined: Wed Jan 13, 2010 10:42 pm

Re: Ignition woes

Post #12 by F-250 Restorer » Fri Sep 13, 2019 4:33 pm

Thanks for the help,guys. Set it back to original t.setting, flipped the wires, and issue was gone. I,m starting to think you guys know what you,re talking about.

Side note: original stator lasted 44 years. Replacement lasted 1!!!! One stinking year. Oh boy.

User avatar
68Flareside240
Registered User
Posts: 111
Joined: Mon Jan 14, 2019 11:52 am
Location: Selma, AL

Re: Ignition woes

Post #13 by 68Flareside240 » Fri Sep 13, 2019 5:34 pm

F-250 Restorer wrote:Side note: original stator lasted 44 years. Replacement lasted 1!!!! One stinking year. Oh boy.


When the heater core when out in my 68 F100 last fall, I was shocked to find it was the original. Just don't make parts like they used to.

F-250 Restorer
Registered User
Posts: 703
Joined: Wed Jan 13, 2010 10:42 pm

Re: Ignition woes

Post #14 by F-250 Restorer » Fri Sep 13, 2019 8:12 pm

68Flareside240 wrote:
F-250 Restorer wrote:Side note: original stator lasted 44 years. Replacement lasted 1!!!! One stinking year. Oh boy.


When the heater core when out in my 68 F100 last fall, I was shocked to find it was the original. Just don't make parts like they used to.


Also, when I mentioned that it lasted one year, that means about 5k miles. That means 6mo of driving for the average person. THAT is scary. I'm trying to find some NOS (New old stock) motorcraft ones on ebay, but even then you don't know the quality. It's better to carry a spare than to flip the cost of a tow.

Mdixon300f100
Registered User
Posts: 155
Joined: Wed May 02, 2018 6:43 am

Re: Ignition woes

Post #15 by Mdixon300f100 » Sat Sep 14, 2019 7:58 am

F-250 Restorer wrote:
68Flareside240 wrote:
F-250 Restorer wrote:Side note: original stator lasted 44 years. Replacement lasted 1!!!! One stinking year. Oh boy.


When the heater core when out in my 68 F100 last fall, I was shocked to find it was the original. Just don't make parts like they used to.


Also, when I mentioned that it lasted one year, that means about 5k miles. That means 6mo of driving for the average person. THAT is scary. I'm trying to find some NOS (New old stock) motorcraft ones on ebay, but even then you don't know the quality. It's better to carry a spare than to flip the cost of a tow.


I do 400 miles a week, the replacement wheels bearing in my Toyota don’t last a year. It’s amazing how poor some replacement parts are...

Who is online

Users browsing this forum: Google [Bot] and 20 guests