ignition trouble i think...
Thread Starter
|
New User
Joined: Nov 2006
Posts: 7
Likes: 0
ignition trouble i think...
well, this is my first post, and mybe you guys could help me. I have a 390 4bbl in a 68' F-250. I love the truck but, when i'm going down the road it (without warning) will quit. no sputters or pops. the tach still reads ok so i know the coil is firing i replaced the coil, points and condenser. a few weeks ago it quit at the end of the street so i coasted it into the yard. I was dead and wouldn't fire at all. the next moring i went out to check the spark, etc. i hit the key and it started and ran beautifuly. any help, it's hard to fix a problem that's there one minute and gone the next.
Hotshot
Joined: May 2004
Posts: 12,170
Likes: 5
From: The hills of No. Calif.
This is an odd one all right. My first thought is a loose wire killing the ignition system, but you say you're still getting a reading on the tach, I assume when the engine is still turning with the momentum of the truck as it slows to a stop, but not firing. Hmm...
The very first thing I would do at this point is to get under the hood and pop off the dist. cap and check the spark right at the source. I like to pull the coil wire from the cap and wedge it somewhere so that the end is about 1/4" from a ground, then, with the points off the cam and closed, (key on) open and let them shut again a few times with my thumbnail. If all is as it should be, you should get spark at the coil wire,as well as at the points themselves. If this is done at night you can often see any shorts in the system that are going to ground as well. I'm wondering if that might be the problem right there...
I assume you've checked for fuel at these times, so you know that it's an electrical problem and not a fuel problem?
You might want to consider a Durapsark conversion as I did on my '68 F250CS (if you prefer cheap, like me!) or a change to some other form of aftermarket electronic ignition.
The very first thing I would do at this point is to get under the hood and pop off the dist. cap and check the spark right at the source. I like to pull the coil wire from the cap and wedge it somewhere so that the end is about 1/4" from a ground, then, with the points off the cam and closed, (key on) open and let them shut again a few times with my thumbnail. If all is as it should be, you should get spark at the coil wire,as well as at the points themselves. If this is done at night you can often see any shorts in the system that are going to ground as well. I'm wondering if that might be the problem right there...
I assume you've checked for fuel at these times, so you know that it's an electrical problem and not a fuel problem?
You might want to consider a Durapsark conversion as I did on my '68 F250CS (if you prefer cheap, like me!) or a change to some other form of aftermarket electronic ignition.
Lead Driver
Joined: Aug 2003
Posts: 7,592
Likes: 10
From: **** hole San Jose ca.
I guessing this is why you replaced coil. points ect. And you still have the same problem.Humm well What, I would do. When it dies out. Hot wire it and see if you can get it started up again. This will by pass your key switch. If it starts you know were to look for your problems. Ford had problems with some types of the key switch pigtails. I had troubles with mind and had to replace it. To hot wire it. Run wire from hot batt.terminal to ign side of coil
hope this helps in some way..my 2cents
orich
hope this helps in some way..my 2cents
orich
Senior User
Joined: Jun 2006
Posts: 198
Likes: 0
From: Vacaville, Ca
Originally Posted by 68'F-250CS
well, this is my first post, and mybe you guys could help me. I have a 390 4bbl in a 68' F-250. I love the truck but, when i'm going down the road it (without warning) will quit. no sputters or pops. the tach still reads ok so i know the coil is firing i replaced the coil, points and condenser. a few weeks ago it quit at the end of the street so i coasted it into the yard. I was dead and wouldn't fire at all. the next moring i went out to check the spark, etc. i hit the key and it started and ran beautifuly. any help, it's hard to fix a problem that's there one minute and gone the next.
Thread Starter
|
New User
Joined: Nov 2006
Posts: 7
Likes: 0
it's getting plenty of fuel and by dead i mean it cranks but don't fire at all, but when it does start (no always) it don't miss a beat, I hot wired it and that seems to cure the problem so back to the parts store for the ignition swich Thanks for the help
Trending Topics
Logistics Pro
Joined: Jun 2003
Posts: 3,928
Likes: 275
When it dies, run out with a test light and check for juice in the obvious places.
Sometimes the insulation on the wiring under the hood on these old trucks gets hard and allows the wires to break in half. I chased a similar problem for a friend of mine and it turned out to be an ignition wire broken in half that would create an open and closed circuit at will. While it was running we started jiggling wires until it died.
Sometimes the insulation on the wiring under the hood on these old trucks gets hard and allows the wires to break in half. I chased a similar problem for a friend of mine and it turned out to be an ignition wire broken in half that would create an open and closed circuit at will. While it was running we started jiggling wires until it died.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Thread Starter
|
New User
Joined: Nov 2006
Posts: 7
Likes: 0
I have replaced the condensor when i did the points and the coil. the primary resitense may be my problem too i had a 4bbl autolite carb with what i think was a bad float, any i back fired and caused a pretty large fire, the paint i got for the black spot on the hood blended well and some of the wires did get burned and even though they look ok from the outside i should try and replace them too although the wire checks out ok with the test light.
Thread Starter
|
New User
Joined: Nov 2006
Posts: 7
Likes: 0
thanks for the help i should have enough work to keep me busy while it sits for the winter. Getting this fixed should renew my trust in the truck whitch is good because it's daily transportation april-october.
Thread
Thread Starter
Forum
Replies
Last Post
DieselMoak
1987 - 1996 F150 & Larger F-Series Trucks
9
Dec 13, 2009 07:06 PM
human_fly_
1973 - 1979 F-100 & Larger F-Series Trucks
16
Dec 16, 2008 08:40 PM