390 no spark issue

B

Brushwolf

Member
Have been around points-equipped Fords for decades and never had this much difficulty getting spark..

390 has new plugs, wires, cap, rotor, condenser and battery/cables. No spark. Ground wire inside distributor to points is fine, though I had also switched that too when nothing else worked.

Hotwired coil direct to battery positive, still no spark.. After checking coil + and - wire continuity with multimeter, I have one at a time changed out everything at least once. Even replaced the entire distributor and coil from known running engine and hotwired coil direct to battery.. Still no spark... Distributor rotor does rotate when the engine is cranked.

Starter seems to crank the engine normally which I have seen in the past that a starter that draws too much amperage can diminish power to coil enough to prevent ignition function. But that does not seem to be happening here.

What could it be? Been through 3 coils, 2 rotors, 2 condensers, 2 coil lead wires, and finally the entire distributor. No results. Am in my 3rd day of this rut...
 
If you have a test light, hook it to the distributor side of the coil (small terminal) and crank the engine. It should flash on and off as you crank. If it never lights, the points or wiring in the distributor is grounded. If it stays lit all the time, the points are not grounding the coil when they close.

This assumes you have power to the ignition switch side of the coil while cranking.
 
cadillac512 said:
If you have a test light, hook it to the distributor side of the coil (small terminal) and crank the engine. It should flash on and off as you crank. If it never lights, the points or wiring in the distributor is grounded. If it stays lit all the time, the points are not grounding the coil when they close.

This assumes you have power to the ignition switch side of the coil while cranking.
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It is hot-wired so no doubt about power. But it does stay on all the time while cranking..
 
The braided fine ground wire inside distributor appears ok. Had swapped out one of those with cleaned up ends into the first distributor. But I will check it in the present distributor too.
 
Brushwolf said:
It is hot-wired so no doubt about power. But it does stay on all the time while cranking..
Click to expand...


If it stays on while cranking then the points are not grounding the coil when they close. Either the distributor isn't grounded, the points/ plate aren't grounded or the wire from points to coil is open. Find the ground problem and you're fixed.
 
ground the Dist with a jumper wire to the ground terminal post on the Battery to make sure the dist. is grounding properly. had a friend with an off topic car this summer had the same problem. my only suggestion was to ground the dist. That cured the problem. turns out the eng block had been painted with the dist out and the dist. was insulated by the paint. I was glad it cured his problem as I was out of answers. maybe this will help you.
 
Got it, I think.. Inspected all inside distributor and it was all fine. But I had done that multiple times before to no avail. So, I took out the NVOS points once again and filed them in case there was any kind of film inhibiting contact cuz there didn't seem to be anything left to change.

When I put them back in it tried to start immediately. Celebrated, but did not fire it up all the way cuz gas line is leaking slightly at fuel pump and have to do a cam break-in on it once started. So will wait til my son gets here Saturday. He is very anxious to hear it run. It is a 61 Galaxie convertible we have been working on for a year and a half and when it is done it will be his car.

Thanks a lot for the test insight. Had not heard of that before.
 
Very interesting. I was going down the road of Alaska Jim, but never saw a distributor not grounding. But thin corrosion on the points is something I hadn’t got to. Glad you found it.

A little research will show you how to turn the engine to the initial timing mark, and use the light on the points trick to static time the initial by turning the distributor. Then it’ll light right off for you when you’re ready. Been years since I’ve done that.
 
Alaska Jim said:
ground the Dist with a jumper wire to the ground terminal post on the Battery to make sure the dist. is grounding properly. had a friend with an off topic car this summer had the same problem. my only suggestion was to ground the dist. That cured the problem. turns out the eng block had been painted with the dist out and the dist. was insulated by the paint. I was glad it cured his problem as I was out of answers. maybe this will help you.
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Yes, we did go round and round on what needs to be grounded and there are a whole lot of repainted parts on this thing. So prior to reaching out I had already hooked up an extra ground wire from solenoid to block and cleaned distributor base and clamp itself to bare metal, the spot it contacts the block and even the threads of the hold-down bolt.

Appears the only thing not to worry about the ground on is the coil body itself.

Thanks for the input!
 
miker98038 said:
Very interesting. I was going down the road of Alaska Jim, but never saw a distributor not grounding. But thin corrosion on the points is something I hadn’t got to. Glad you found it.

A little research will show you how to turn the engine to the initial timing mark, and use the light on the points trick to static time the initial by turning the distributor. Then it’ll light right off for you when you’re ready. Been years since I’ve done that.
Click to expand...

"Light on the points trick".... Care to elaborate on that? I have a new timing light on hand as I lost track of the 50 year old light I had before. But have yet to use it.

Thanks
 
I doubt very much that the painted engine block is insulating ground from the distributor. You may notice that the bottom of the dizzy has a collar that sits on top, but under that is still a thick aluminum ledge that makes contact with the bore in the engine block. If that bore is clean and unpainted, your dizzy is grounded. Aside from that, the dizzy hold-down bracket gives electrical continuity from the bolt, thru the bracket to top of engine block. Scrape paint off under that bracket, and bolt it back down. It will be grounded.
I am betting on bad condensers right out of the box. Gotta keep you fingers crossed nowadays when buying these chinese made junk condensers. If you have a known good one, keep it till hell freezes over. Are you sure you have the right capacity?
Make sure rotor arm is making good contact with lead pile on underside of center of dizzy cap. If rotor is not touching that lead, it won't start. Lot of new ones now are smashed down too much and don't touch. You may need to pull up a little on that arm, but not too much or it will wear the lead off that center tower in the cap.
How about a coil test to see if it's any good. Autozone may text it for you for nothing.
 
The link K posted explains it pretty well. Remember, when the light comes on, the points have opened. When the primary coil winding loses power, the magnetic field collapses, and the secondary coil creates the high voltage that goes (via the cap and rotor) to the spark plug. I was taught to set the engine damper with the markings to the initial advance setting (on our y blocks, 6* per the factory), so when the points open it is at the 6* initial rather than TDC. (Not to confuse matters, but when you get to TDC it can be #1 or whatever is opposite in the firing order. Doesn’t matter, the cap and rotor handle that).

The advantage to that is that if air/fuel/compression are all in order the engine starts. Run the rpm up for cam break in, check and keep checking for leaks, and then use your timing light to double check the timing. At the 2000-2500 rpm for cam break in it’ll be more than initial. I don’t know about an FE, but a Yblock will be up around 28-35 with the vacumn advance disconnected. I normally do the cam with the vacuum advance disconnected and plugged, one less thing to worry about.

Sounds like you’ve e got it figured out. Good luck and enjoy.
 
So, I took out the NVOS points once again and filed them in case there was any kind of film inhibiting contact cuz there didn't seem to be anything left to change.

When I put them back in it tried to start immediately. Celebrated, but did not fire it up all the way cuz gas line is leaking slightly at fuel pump and have to do a cam break-in on it once started.
Click to expand...

When installing points, you always take a clean piece of paper or cardboard and wipe the points clean (closed). Being CHI-COM, there may be leftover soy sauce on them.

Whatever you do, do not dry crank the engine continuously with a needed cam break-in. It will wipe the assembly lube off the cam journals and lifter foot.

A DIST GRD can be interrupted with heavy engine paint. It is a dialectic. It is recommended to run a separate GRD WIRE from the DIST BODY to a clean GRD, especially with points.
 
I had a very close experience with the 351C in my Ranchero. Started, ran, did the cam break-in, let it cool, started again for another twenty minute run, shut it off and it didn't hit a lick again. Hours of messing with timing, changing everything still no joy. Distributor was a brand new rebuilt. Finally found the issue when messing with the points. They would only hit intermittently. Put a new set of USA manufactured points in and it hasn't missed a lick since!
 
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