Go Back   Ford Truck Enthusiasts Forums > Performance, Engines & Troubleshooting > FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
Sign in using an external account
Register Forgot Password?


Welcome to Ford-Trucks Forums!
Welcome to Ford-Trucks.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the Ford-Trucks Forums community today!





 
Reply
 
LinkBack Thread Tools Search this Thread
  #1 (permalink)  
Old 04-08-2009, 09:30 PM
73CaliF100's Avatar
73CaliF100 73CaliF100 is offline
Senior User
 
Join Date: Jan 2009
Location: Nor Cal
Posts: 134
73CaliF100 is starting off with a positive reputation.
Proper way to check coil?

I recently purchased a Haynes manual hoping to find some specifications or a procedure to check the ignition coil, but it just says replace it.

Does anyone know if there is a method to test the ignition coil?

I have a 390 that is exhibiting some popping, sputtering, hesitation, and backfireing out the exhaust.

Thanks!
Reply With Quote
  #2 (permalink)  
Old 04-08-2009, 10:06 PM
Alvin in AZ's Avatar
Alvin in AZ Alvin in AZ is offline
Postmaster
 
Join Date: Aug 2005
Location: Gadsden Purchase
Posts: 2,760
Alvin in AZ is gaining momentum as a positive member of FTE.Alvin in AZ is gaining momentum as a positive member of FTE.
Betcha money it ain't your coil doing that. ;)

The way to check your coil is two ways.
First with an ohm meter (a coil is nothing more than a transformer) check
both windings for resistance...
Primary is 1.0 to 2.0 ohms.
The secondary is 7,000 to 13,000 ohms.
That's straight from my Ford Shop Manuals. ;)

The other way is to test how long of a gap it can jump with a coil tester.
I've never used one of those and so far hadn't needed to. ;)
Anybody suggest I get one? ...and "why" would be cool. :)

Want to post more about the problems and what you've done to it lately?
A progression of how it got to acting up like it is, if it didn't happen all at
once, would be helpful.

Alvin in AZ
Reply With Quote
  #3 (permalink)  
Old 04-09-2009, 01:27 AM
fordeverpower's Avatar
fordeverpower fordeverpower is offline
Postmaster
 
Join Date: Jul 2003
Location: iowa
Posts: 3,913
fordeverpower is starting off with a positive reputation.
i thought exhaust valves are the problem with exhaust popping and what not. I also don't think its the coil.
__________________
Matt Drury
78 F100 390 2wd c6
79 F150 400 np435 4x4
79 f150 390 rip!
95 f150 4x4 351w
Avatar is Barry Rabotnick's emc motor!
Reply With Quote
  #4 (permalink)  
Old 04-09-2009, 08:54 AM
73CaliF100's Avatar
73CaliF100 73CaliF100 is offline
Senior User
 
Join Date: Jan 2009
Location: Nor Cal
Posts: 134
73CaliF100 is starting off with a positive reputation.
I have read a few threads about similar issues and I am trying to pick the low hanging fruit first. Initially when I got the truck, it was having a hard time idling from a cold start. I went through and checked the vacuum lines and found an open port at the front of the carb. I plugged it and it seemed to run a little better, but not great. I set the timing (with a light) and found that the open port on the carb was for the EGR. After reconnecting the EGR, the cold start issue seemed to come back. Basically, I have to start it and stay on the gas until the engine warms up a bit and then it will idle on it's own. However, the real issue that I'm having now is; after the engine is up to operating temp I can take off at low RPM, but if I give it some gas the truck will shudder like it is starved for fuel. As I mentioned, I have read a few threads on this same issue and I plan to check; coil, timing, vacuum/mechanical advance, fuel delivery, etc...
Reply With Quote
  #5 (permalink)  
Old 04-09-2009, 01:10 PM
Krewat's Avatar
Krewat Krewat is offline
Super Moderator
 
Join Date: Jul 2002
Location: Long Island USA
Posts: 34,343
Krewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputation
Sounds more like accelerator pump - look down the throat of the carb, and pump the throttle, it should squirt quite a decent amount of gas down the throat.
__________________
- art k. - Moderator for the Superduty, V10, 6.2L and FE forums
'13 Taurus SHO 3.5L Ecoboost w/Perf Pkg
'01 F250SD SC SB XLT V10 4x4 Volant CAI Hedman headers 5-star custom tunes on SCT X3
'97 Cougar XR7 30th Anniv Edition 4.6L
'74 F250 Highboy FE390 deceased!
I've been wrong before, I'll be wrong again. Just wait and see. ®
Reply With Quote
  #6 (permalink)  
Old 04-09-2009, 03:19 PM
Bear 45/70's Avatar
Bear 45/70 Bear 45/70 is offline
Post Fiend
 
Join Date: Mar 2004
Location: Union, Washington
Posts: 6,056
Bear 45/70 has a good reputation on FTE.Bear 45/70 has a good reputation on FTE.Bear 45/70 has a good reputation on FTE.
I think both your cold idle problem and the acceleration issue are carb related. The cold idle is a maladjusted choke and cold idle speed issue. I'm with Krewat on the second, sounds like a dead or badly adjusted accelerator pump linkage.
__________________
Bear 45/70

"Earth has its boundaries, but human stupidity is limitless."
Gustave Flaubert (1821-1880)
Reply With Quote
  #7 (permalink)  
Old 04-09-2009, 03:27 PM
peters_f350 peters_f350 is offline
Freshman User
 
Join Date: May 2008
Location: Kamloops, BB
Posts: 39
peters_f350 is starting off with a positive reputation.
Im having a coil problem with my 1981 Firebird with a 267 V-8, I bought a new one and it fried it again, is it the resistor.
Reply With Quote
  #8 (permalink)  
Old 04-09-2009, 03:33 PM
Bear 45/70's Avatar
Bear 45/70 Bear 45/70 is offline
Post Fiend
 
Join Date: Mar 2004
Location: Union, Washington
Posts: 6,056
Bear 45/70 has a good reputation on FTE.Bear 45/70 has a good reputation on FTE.Bear 45/70 has a good reputation on FTE.
Does you ignition system even have a resistor? Originally the resistor was a point protection thing. A well designed electronic system should not need or have one. I would suspect the ignition box or computer. Quite often in you situation you will be better off replace the coil, sensor and box to prevent the exact issue you had with the new coil.
__________________
Bear 45/70

"Earth has its boundaries, but human stupidity is limitless."
Gustave Flaubert (1821-1880)
Reply With Quote
  #9 (permalink)  
Old 04-09-2009, 04:05 PM
Krewat's Avatar
Krewat Krewat is offline
Super Moderator
 
Join Date: Jul 2002
Location: Long Island USA
Posts: 34,343
Krewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputation
Bear, I just looked at some Duraspark schematics I have in my Motor's manual (1979 truck repair) and it shows resistors for most of the setups.

Ford 1973-74, 1975, 1976 (all called "Breakerless" not Duraspark) have them.

Duraspark I does NOT.

Duraspark II DOES.

However, it alludes to something being different with California for 77-78 Duraspark, saying "internal regulation" for the coil reduces overheating of coil and module, and non-California using a reduced-value resistor to achieve higher spark voltage.

From what it looks like, Duraspark I was just California, maybe using a resistor internally to the box.
__________________
- art k. - Moderator for the Superduty, V10, 6.2L and FE forums
'13 Taurus SHO 3.5L Ecoboost w/Perf Pkg
'01 F250SD SC SB XLT V10 4x4 Volant CAI Hedman headers 5-star custom tunes on SCT X3
'97 Cougar XR7 30th Anniv Edition 4.6L
'74 F250 Highboy FE390 deceased!
I've been wrong before, I'll be wrong again. Just wait and see. ®
Reply With Quote
  #10 (permalink)  
Old 04-09-2009, 04:18 PM
Bear 45/70's Avatar
Bear 45/70 Bear 45/70 is offline
Post Fiend
 
Join Date: Mar 2004
Location: Union, Washington
Posts: 6,056
Bear 45/70 has a good reputation on FTE.Bear 45/70 has a good reputation on FTE.Bear 45/70 has a good reputation on FTE.
Quote:
Originally Posted by Krewat View Post
Bear, I just looked at some Duraspark schematics I have in my Motor's manual (1979 truck repair) and it shows resistors for most of the setups.

Ford 1973-74, 1975, 1976 (all called "Breakerless" not Duraspark) have them.

Duraspark I does NOT.

Duraspark II DOES.

However, it alludes to something being different with California for 77-78 Duraspark, saying "internal regulation" for the coil reduces overheating of coil and module, and non-California using a reduced-value resistor to achieve higher spark voltage.

From what it looks like, Duraspark I was just California, maybe using a resistor internally to the box.
A lot of the resistor with electronic ignition was due to there being point ignition systems going into the same vehicles that also had electronic available. Cheaper to only have one wiring harness.
__________________
Bear 45/70

"Earth has its boundaries, but human stupidity is limitless."
Gustave Flaubert (1821-1880)
Reply With Quote
  #11 (permalink)  
Old 04-09-2009, 09:36 PM
Redmanbob's Avatar
Redmanbob Redmanbob is offline
Postmaster
 
Join Date: Oct 2005
Location: Mddl A MexCans
Posts: 3,770
Redmanbob is gaining momentum as a positive member of FTE.Redmanbob is gaining momentum as a positive member of FTE.
he said he has an 81' Firebird.. hello....
__________________
66 F100 352FE / Cruiso
71 F250 360FE /C6
CRATE = Cant Really Appreciate The Engine..
Reply With Quote
  #12 (permalink)  
Old 04-09-2009, 09:52 PM
Bear 45/70's Avatar
Bear 45/70 Bear 45/70 is offline
Post Fiend
 
Join Date: Mar 2004
Location: Union, Washington
Posts: 6,056
Bear 45/70 has a good reputation on FTE.Bear 45/70 has a good reputation on FTE.Bear 45/70 has a good reputation on FTE.
Quote:
Originally Posted by Redmanbob View Post
he said he has an 81' Firebird.. hello....
Wasn't responding to that post but to krewat's. I could care less about the Firechicken.
__________________
Bear 45/70

"Earth has its boundaries, but human stupidity is limitless."
Gustave Flaubert (1821-1880)
Reply With Quote
  #13 (permalink)  
Old 04-09-2009, 10:04 PM
Redmanbob's Avatar
Redmanbob Redmanbob is offline
Postmaster
 
Join Date: Oct 2005
Location: Mddl A MexCans
Posts: 3,770
Redmanbob is gaining momentum as a positive member of FTE.Redmanbob is gaining momentum as a positive member of FTE.
Quote:
Originally Posted by Bear 45/70 View Post
Wasn't responding to that post but to krewat's. I could care less about the Firechicken.
__________________
66 F100 352FE / Cruiso
71 F250 360FE /C6
CRATE = Cant Really Appreciate The Engine..
Reply With Quote
  #14 (permalink)  
Old 04-15-2009, 07:59 AM
73CaliF100's Avatar
73CaliF100 73CaliF100 is offline
Senior User
 
Join Date: Jan 2009
Location: Nor Cal
Posts: 134
73CaliF100 is starting off with a positive reputation.
Well Guys...I wanted to let you know that my issues seem to have been solved by a good tuneup, i.e. points, condensor, cap, rotor, and plugs. I put everything in, gapped the points and set the timing. It all seems pretty good now with the exeption of my choke. I will be tweaking the choke and checking the carb settings this weekend. I'm also installing headers and duals...can't wait to fire it up after that.
Reply With Quote
  #15 (permalink)  
Old 04-29-2009, 04:12 PM
Lvcrprts's Avatar
Lvcrprts Lvcrprts is offline
Senior User
 
Join Date: Dec 2008
Location: Yakima, WA
Posts: 193
Lvcrprts is starting off with a positive reputation.
In my much younger years....Redneck way is to pull the coil wire from the distibutor with your hand while it is running... if it shocks the hell out of you then the coil is good. Made my arm hurt for 3 days. Guess the stock coils don't put out nearly what the new ones do. Here's your sign LOL
__________________
68' F250 C\S Waste's gas but hauls ***.

Build a truck that wakes the neighbors.


Open headers better than sex.
Reply With Quote
Old 04-29-2009, 04:12 PM
Reply

Go Back   Ford Truck Enthusiasts Forums > Performance, Engines & Troubleshooting > FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)

Tags
352, 79, acceleration, coil, duraspark, f250, ford, issue, overheating, ranger, running, sparks, stay, test, wont

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 On
Trackbacks are On
Pingbacks are On
Refbacks are On
Forum Jump



All times are GMT -5. The time now is 02:03 PM.


Powered by vBulletin® Version 3.7.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Advertising - Terms of Use - Privacy Statement - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup