Hello FTE Friends,
On June 12th, my wife, son and I were cruising about 55 - 60 MPH, to her parents for her celebratory "Posole" birthday meal when suddenly I lost power followed by a backfire type of bang!
Once towed home and safe, back to my wife's birthday meal...
The next day doing trouble shooting I discover that spark seems week coming out of the coil.
She sports (my truck) a Professional Product's Powerfire Ignition Distributor set up. Called the kind folks up there and they suggested I change the internal module. Did so and spark still seems week. Also changed the coil and nothing.
So, I'm here to ask a simple question... WTF is going on?

Happily Stranded...



Somewhere Tulare County, CA

 

Always check for good battery connection and good grounds. Beyond that, you could disconnect the wire from the negative (-) side of the coil and with the ignition switch 'on' use a jumper wire to the negative coil post and touch to ground to see if the spark improves. Generally, backfire through the exhaust is caused by late ignition timing or a failing module. And then there's the 'no spark at all' for a second or more followed by the spark returning and igniting the unburnt fuel that's now in the muffler. A bad condensor 'might' cause that but in my experience a bad condensor usually causes the exhaust to make my eyes tear-up really fast.

 

Check the cap and rotor, in particular the carbon contact in the cap.

 

Do you have an electronic ignition or is it points? Could be worn points or rotor. ???

Sorry I'm not of much help Paul. Looked like a nice day!



Thanks for stealing my thunder, Ross. That was my time to post, not yours!

 

This is a great shot of your family, Paul.

 

How many miles on the motor? Sometimes a skipped tooth on the timing change can cause a strong backfire followed by engine dying. When diagnosing an engine issue, I start with verifying it is getting fuel to and through the carb. does gas shoot into the carb throats when you quickly move the throttle linkage to wide open? Check with a flashlight, not with a candle or match! LOL
If the engine is getting gas, next I would do a compression check to see if you have maybe cracked a ring or burned a hole in a piston, or a burned or stuck valve. Next if it will run check the timing. What motor is in your 56?

 

Believe he's got a 351W C6.

 

Got gas????

 

Hi Guys,
Yes, it's got the 351W & C6
Yes it is getting gas - plenty of it
Haven't looked into the skipped tooth on the timing chain but to answer the question, the engine has around than 3,000, though the odometer reads around 6,000 due to the rebuild after chewing up the distributor & Cam gears my 1st time around...

Friends, this is my putt around town, go to my chemo maintenance vehicle. No burning rubber (okay, sometimes - but just a little tiny bit) No racing of any kind...

Noted things to check;
Check the cap and rotor - thanks ALBUQ
mOROTBREATH, I believe it's electronic. This straight from their site...

"Professional Products Ford 351W V8 Powerfire Ignition Distributor
The Powerfire I represents the latest state-of-the-art design in modern ignitions systems. It's most outstanding feature is it has an external **** that allows timing adjustment while the engine is running. Each click of the **** advances or retards the timing 1/2 degree. This distributor can be used with the Powerjection systems but the spark control feature of the Powerjection cannot be enabled. Works for 351W Small Block Ford.
Kit includes:
Rotor
Coil dust cover
High-RPM control module
High-energy 42k volt coil
Low-resistance brass coil bushing
Distributor cap with brass terminals for improved conductivity

AXracer, are engines capable of skipping a tooth, backfiring and leaving one stranded while driving normal 50-55 MPH on a Sunday afternoon? Honestly, pardon the question and my ignorance

CharlieLed - PLENTY but thanks. Brings back memories of when the pickup was clogged inside the tank a few years ago...

 

I mention the gas because I had a similar situation in high school with a 40 Plymouth coupe I was driving. After pulling the head and doing a lot of other "unwarranted" maintenance actions, my next door neighbor (an auto mechanic) came over and asked "Do you have gas". I didn't and felt pretty foolish for missing such an obvious (at least now it's obvious) fault. Since your ignition seems to have weak spark is there any way you can revert back to a stock setup and retest?

 

When you say stock, do you mean like what it came with in '78? Then no. Because the original set up required having modules and all kinds of stuff on the inner fenders and I opted to rid of the mess by choosing this distributor. Basically it simulates a Chevy, I guess... I wonder if I had opted for the pricier MSD I'd be having this issue?

 

Many folks who have upgraded ignition systems still have the stock setup on the shelf someplace. I am not familiar with the Professional Products ignition line...I have used some of the harmonic balancers however. I guess that the point I was trying to make was to remove the questionable component (ignition) from the system and see if the problem persists. I use MSD distributors and controls on my engines so I have a few around the garage that I can fall back on to test any problem I might have. However you can make it happen you might want to replace the ignition system to verify that it either is or is not at fault.

 

Good points CharlieLed
Will keep us all posted...

 

That is very suspicious. What was the root cause of that failure? Distributor and cam gears don't just chew themselves up for no reason.

 

Hi Pete,
The chewing up of the cam happend on my original engine build when I failed to marry the cam and bearing gears. Lesson learned!

UPDATE:
Changed distributor pick up module. NADA
I get spark if I arc it to a bolt but I get no spark at the end (spark plug)
Jumped in and ordered a new distributor cap and rotor from manufacturer - against my better judgement (wanted the MSD set up in the first place) awaiting delivery.
Happy 4th of July weekend friends!
Paul