351c wont start, help

[1969_Mach1]

So is it possible to have a bad distruber when it is new out of the box? If so what goes bad on them? Condenser? The points look great rotor is kind of worn, took wire off and I stalled spark plug turned engine over I had a white spark not blue from it, all plugs fouling out, do u think the condenser went bad or the rotor button. Will I need new plugs too, this is my second set? I did test the coil with a brand new one and still the same issue, trys to start almost does then nothing just turns over.

First:  Have you set the point gap correctly?  Possibly it wasn't set correctly.  Condensers do go bad.  Once in great while a rotor will go bad and instead of the spark traveling from the center button to the outer tip of the rotor, it will short to ground on the shaft below the rotor.

Second:  Have you tried temporarily running a jumper wire directly from the battery to the positive side of the coil?  This would be the first thing I'd try after verifying the point gap is correct.  It's possible the 12V circuit to the coil during cranking is not working.  In that case you will only get the 6V or 9V through the resistor wire while cranking.  Don't leave the jumper wire on it too long as you can damage the coil or points.

Third:  What spark plug wires are you using?  Are they new or are you reusing old wires?  I've had motors not start due to weak spark from bad spark plug wires.

Fourth:  Do you have the base timing set close enough to start?  Have you tried rotating the distributor a little when attempting to start it?

Clean your spark plugs with carb cleaner, a tooth brush, and let them air dry or blow them dry if you have an air compressor or heat gun.  Hold a match or lighter to them to make certain all fuel and carb cleaner is off.  Make certain they are gapped correctly.  Put a little anti-seize compound on the threads so they are easy to remove later.  I've cleaned spark plugs and reused them when they get fuel fouled.

Have you verified you don't have a needle and seat stuck open in carb and it's flooding?  If you are trying to start it with the choke closed it might flood.  The Holley 750 DP carb doesn't need much, if any choke to get a cold motor started.  Especially on a small block.  It has fairly rich idle circuits.  You'll have to tinker with the choke after you know the motor runs okay.

FYI:  If your hood is installed, have your air cleaner installed when trying to start it.  If it backfires the flames could burn the paint on the hood.  Also, with the hood on, do not stand in front of the car if the air cleaner is off when tuning.  Any backfires will travel up the hood and onto you.

[My70mach1]

Points are set at .016 ,yes I have tried the wire from the + battery to the coil, still no spark. The spark plug wires are from cjpony and are the date code correct wires and are new, so pretty much OEM one I guess.for the carb issues I just replace the carb with a new one from the parts house an elbrock 650 4bbl and its brand new. Timing should be close really close I have tdc and rotor points at number 1 forwards the intake right side if in front of car.and number 1 cylinder is at the top. I do have a old distruber that came with the car which has doubled points and a condenser with are all new, replace when I got the car to get it to run before I took engine out to have body redone and set the engine out to be redone.

[Mustangmike]

Not sure I fully understand everything correctly.  You have a new distributor but the cap and rotor are not new?  I thought a cap and rotor would come new with the distributor?? What brand and type of distributor did you install?

The issue I had with my distributor was at one point the distributor was converted to a Pertronix type ignition. When the Pertronix failed I ended up dead on the side of the road and did a roadside conversion back to the points. Consequently, the ground wire in the distributor was missing which I completely overlooked. Although I got the car running it never ran at full power. It had no snap. Ultimately, the engine failed on me a second time shutting down and not starting. I ended up popping in a dual point distributor a buddy of mine gave me and the car immediately fired right up with more power than it ever had. The problem was the distributor ground wire the whole time.

I am not familiar with factory tachometers and how it may play into the your problem. I will leave that to 1969 Mach 1 and JTS. I am just trying to share my experience with you which sounds very similar to what you are experiencing.

[My70mach1]

So the distributor is a motor craft- rebuilt, the old distruber was the dual points which I am not using bc it was just worn out like the gear and I wanted to start off with all some what original parts bc it was all hacked up. And the cap and rotor button are original as far as I can remember it took 3 years to get the body back from bodyshop, the new distributor is a single points with a single vac advance on it which I bought from cj pony parts. And I have I the ground wire from it to the neg on the coil

[My70mach1]

Oh I did look at the cap and button bc didnt see and cracks that I could tell

[Mustangmike]

Points are set at .016 ,yes I have tried the wire from the + battery to the coil, still no spark. The spark plug wires are from cjpony and are the date code correct wires and are new, so pretty much OEM one I guess.for the carb issues I just replace the carb with a new one from the parts house an elbrock 650 4bbl and its brand new. Timing should be close really close I have tdc and rotor points at number 1 forwards the intake right side if in front of car.and number 1 cylinder is at the top. I do have a old distruber that came with the car which has doubled points and a condenser with are all new, replace when I got the car to get it to run before I took engine out to have body redone and set the engine out to be redone.

I am just throwing this out there and you are confident that everything else is correct.  Make sure the distributor you are using has a good ground wire between the distributor plates and the housing.  This will cause a no start situation. Also sounds like your plugs are fouled from pumping the accelerator pedal. Like 1969 Mach 1 mentioned you can end up with a carb fire. It happened to me.

[Mustangmike]

Oh I did look at the cap and button bc didnt see and cracks that I could tell

Is the cap and rotor a matched set?

[My70mach1]

The ground from the distributor? The black wire that I hook up to the coil is that waht you mean. Or is it inside the distributor? And does that wire ground itself inside the coil? Not sure if they are a match set.

[1969_Mach1]

**** If you connect a test light (not self powered) to ground and touch the probe to the negative side of the coil when cranking, does it blink on and off?  If it doesn't blink and stays on or off, and there is power to the positive side of the coil, you have a problem inside the distributor, points, condenser, wire open or shorting to ground.  If it blinks the problem is in the secondary side of the ignition system.  Secondary side is the high voltage stuff.  The coil, spark plug wires, rotor, dist cap, and spark plugs.

**** Not certain I understand your location of #1 cylinder on the engine.  It should be the front cylinder on the passenger side of the car (U.S. cars at least).  To be certain, stand to the side of the motor you will see one side of the motor is farther forward.  Number 1 is the front cylinder on that side.  This works for all V8's, and V6's that I know of.

Sounds like you have been checking the spark at the plugs.  What is the spark like coming out of the coil?  If you have a DVOM (digital-volt-ohm-meter) check the resistance in the plug wires.  Rule of thumb for stock plug wires is roughly 1000 ohms per inch.  So a 24" long wire would have roughly 24000 ohms resistance.

I use MSD plug wires.  Yes definitely not an original look.  But, if you compare resistance, stock is 1000 ohms per inch, MSD is 50 ohms per foot.  I prefer an original look.  But for items like ignition system, an original look is less important than performance to me.

If you cannot check your plug wires, do you at least have another coil wire you can use to test the spark coming out of the coil?  I typically use this tool below to check spark on low output stock ignition systems.  You'll notice the larger gap the spark has to jump.  That is to simulate the additional resistance created by the cylinder pressure.  If it doesn't jump the gap on the tester, it won't fire in the cylinder.

The distributor doesn't use an external ground wire.  The points ground through the distributor.  Just a thought, none of the wires inside the distributor are touching ground?






 

[Mustangmike]

**** If you connect a test light (not self powered) to ground and touch the probe to the negative side of the coil when cranking, does it blink on and off?  If it doesn't blink and stays on or off, and there is power to the positive side of the coil, you have a problem inside the distributor, points, condenser, wire open or shorting to ground.  If it blinks the problem is in the secondary side of the ignition system.  Secondary side is the high voltage stuff.  The coil, spark plug wires, rotor, dist cap, and spark plugs.

**** Not certain I understand your location of #1 cylinder on the engine.  It should be the front cylinder on the passenger side of the car (U.S. cars at least).  To be certain, stand to the side of the motor you will see one side of the motor is farther forward.  Number 1 is the front cylinder on that side.  This works for all V8's, and V6's that I know of.

Sounds like you have been checking the spark at the plugs.  What is the spark like coming out of the coil?  If you have a DVOM (digital-volt-ohm-meter) check the resistance in the plug wires.  Rule of thumb for stock plug wires is roughly 1000 ohms per inch.  So a 24" long wire would have roughly 24000 ohms resistance.

I use MSD plug wires.  Yes definitely not an original look.  But, if you compare resistance, stock is 1000 ohms per inch, MSD is 50 ohms per foot.  I prefer an original look.  But for items like ignition system, an original look is less important than performance to me.

If you cannot check your plug wires, do you at least have another coil wire you can use to test the spark coming out of the coil?  I typically use this tool below to check spark on low output stock ignition systems.  You'll notice the larger gap the spark has to jump.  That is to simulate the additional resistance created by the cylinder pressure.  If it doesn't jump the gap on the tester, it won't fire in the cylinder.

The distributor doesn't use an external ground wire.  The points ground through the distributor.  Just a thought, none of the wires inside the distributor are touching ground?






 

Thanks for explaining the internal ground wire.  I fell asleep early last night.  I am not sure this is the problem My70Mach1 is having but it all the symptoms are identical to what I was experiencing so it is worth looking at.  Actually found this online that talks about the issue I was having. After converting back to points the car ran again but erratic as the article indicates. Because the car was running like it had poor performance I thought I had a carb issue. Ultimately the car died in my driveway and did not start. The problem was in the distributor the whole time:

AFTERMARKET IGNITIONS
Stock Ford distributors have one major shortcoming: their shaft bushings don’t receive sufficient
lubrication for long life. They wear out quickly. As a result, excessive shaft-side play causes
irregularities in point dwell and gap. The aftermarket offers alternatives to the stock Ford ignition
system.

If you are attached to your stock Ford distributor, Pertronix has fast answers with its Ignitor and
Ignitor II retrofit ignition modules. The Ignitor module installs in 15 minutes and never requires
service for the life of the module. Remove the ignition points and condenser. Then fasten the
Ignitor to the breaker plate and connect the leads, just like you would a set of points. Then set the
air gap and install the shutter wheel. Pop on the rotor and distributor cap, and the job is finished.
The beauty of the Ignitor is its simplicity. No periodic maintenance required and no one knows it’s
there but you. It’s perfect for the stock, original driver that you would like to keep stock in
appearance. One more thing about the Ignitor. Should it fail, you can reinstall the points and
condenser, which will get you back on the road in short order. The Ignitor has an excellent
reputation for reliability, so failure is uncommon.

If when you install the Ignitor the engine will not start, or operation is erratic, check the ground first.
There should be a ground strap between the breaker plate and the distributor housing, just like
Ford did it from the factory. If the ground strip is missing, the engine likely will not start, or it will
mysteriously shut down and not restart.