Ignition Problems
Thread Starter
|
Tuned
Joined: Oct 2016
Posts: 255
Likes: 2
From: South dakota
Ignition Problems
What could possibly be wrong? I have a 73 f-250 WITH A 390 STANDARD IGNITION SYSTEM.Problem is when it gets run a bit the engine starts to cut out and I loose tach signal intermittently when it is missing and cutting out. I changed the Spark plugs the wires New distributor points condenser coil And no matter what I do It does not change anything. Could it be possibly the resister wire Failing? Or a Faulty wire or connection? How would I test to see if its the ignition wire?
Can I just temporarily bypass the Resistor To see if it still runs bad? Truck always starts good but always has a flutter or stumble as it gets warmer. Engine was overhauled 2500 miles ago so engine condition is not the issue. HELP! What is the Problem?
Can I just temporarily bypass the Resistor To see if it still runs bad? Truck always starts good but always has a flutter or stumble as it gets warmer. Engine was overhauled 2500 miles ago so engine condition is not the issue. HELP! What is the Problem?
Thread Starter
|
Tuned
Joined: Oct 2016
Posts: 255
Likes: 2
From: South dakota
It is Standard Ignition NON electronic Points and condenser would not have an Ignition box. It does have voltage enough to light a 12 volt bulb dimly. Question tho, could a bad Ignition switch cause the Loosing voltage problem?
Everything else in the truck works fine just the engine bucks and jerks when it gets warmed up. Cuts out when you get on it real hard then gets to the point where you cannot keep it running very well
Everything else in the truck works fine just the engine bucks and jerks when it gets warmed up. Cuts out when you get on it real hard then gets to the point where you cannot keep it running very well
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
You could bypass the resistor, though not for very long. It's there for a reason. The points will burn up without it.
Where are you sourcing points and condenser?
The modern replacement parts sold at the auto parts shops are JUNK, even remanufactured distributors sport these POS. Try a good old school Motorcraft or Echlin condenser from "back in the day". I have 60 year old condensers that test fine at 600 volts DC. The new ones can't hang. In fact, replace the condenser even if it hasn't failed yet, because it will.
Could be a defective ignition coil as well. The key here is the issue arises when it warms up. Heat.
Coil or condenser is the likely culprit. The tach drops out, when the secondary high tension (spark) drops out.
Where are you sourcing points and condenser?
The modern replacement parts sold at the auto parts shops are JUNK, even remanufactured distributors sport these POS. Try a good old school Motorcraft or Echlin condenser from "back in the day". I have 60 year old condensers that test fine at 600 volts DC. The new ones can't hang. In fact, replace the condenser even if it hasn't failed yet, because it will.
Could be a defective ignition coil as well. The key here is the issue arises when it warms up. Heat.
Coil or condenser is the likely culprit. The tach drops out, when the secondary high tension (spark) drops out.
Logistics Pro
Joined: Jul 2005
Posts: 4,217
Likes: 154
You could bypass the resistor, but definitely only temporarily. Ideally, you could go to Radio Shack or where ever, and get a similar resistor, and wire it inline with the straight wire.
Coil should only see 12V during cranking, normally.
Coil should only see 12V during cranking, normally.
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 787
From: Simi Valley, CA
OP has a 1973 F250: DuraSpark electronic ignition introduced in 1974, but not all vehicles have it until 1976.
Trending Topics
Laughing Gas
Joined: Mar 2016
Posts: 1,086
Likes: 466
From: Tennessee
Yeah didnt notice that, when the comment was made I looked back at the OP and saw the date... Duh!
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
Laughing Gas
Joined: Nov 2013
Posts: 1,207
Likes: 60
From: S.E. Louisiana;so far USA
It sounds like a sad connection somewhere in the primary side of the ignition circuit. You may have to trace out the circuit with a voltmeter while the problem is occurring. It could be the resistor wire, but more likely a sad connection somewhere or in the switch.
Also as mentioned, don't "***-u-me" that "new" means "good". Try to verify each component's performance independently.
Also as mentioned, don't "***-u-me" that "new" means "good". Try to verify each component's performance independently.
Thread Starter
|
Tuned
Joined: Oct 2016
Posts: 255
Likes: 2
From: South dakota
well Guys, I think I found my problem! Went and replaced the Points and condenser with New Quality ones from Napa Echilin brand and it seems like problem solved. Drove it all over this afternoon both slow and Fast and it never sputtered or quit. I bench tested the old condenser and it would definitely cause a miss sometimes. Just hooked it up to a battery coil set up and simulated the spark and it sparks sometimes and sometimes not. So I Assume problem solved !
Fleet Mechanic
Joined: Aug 2004
Posts: 1,311
Likes: 31
From: Nevada
Right on
Yes'er, I went cheap with my ignition parts recently on my rebuild and had nothing but problems.... Spent a few more bucks on quality parts and it runs like a champ.........One of those lessons we have to keep learning ..
Thread
Thread Starter
Forum
Replies
Last Post
nmig17
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
2
Jul 25, 2014 08:05 AM
barca_texas
Big Block V8 - 385 Series (6.1/370, 7.0/429, 7.5/460)
5
Oct 6, 2005 02:03 PM
hatemakings/n
Electrical Systems/Wiring
2
Jun 18, 2005 08:34 PM