239 flatty no spark help!!

S

santino2010

Member
hello all I am new to this site so I am trying to figure out what could be wrong wit my 239 flatty..
it started up fine then no start . I checked one of the plug wires but weak spark, then tried turning it on once again and it did start up ran it for a few minutes then shut it off ,and once again no start checked a different plug wire NO SPARK THIS TIME:confused::confused::confused:..

how should I go about this??? any help would be much appreciated:)
this is my first flathead

thank you
 
I would first check for a loose wire to coil and key. Then replace the coil, or hot wire the coil and go from there.
 
The first thing to check is the condition of the points in the dist. What is the gap, are they corroded, check the wire from the coil to the points for bare spots.
 
And remember - never leave your ignition switch on/energized or you will toast the coil (and join the "I did it too" club).

It only takes a couple of minutes to ruin and it's easy to forget when you are running down a problem.
 
Unlike modern computer run cars the old points and coil system is quite simple. With the ignition switch on check to see if you have power to and through the coil. If not find out why and repair that problem. If you do have power to and through the coil the next thing I would do is replace the condenser. If you still don't have spark then either your points are closed or the power from the coil is not reaching the points, the wire from the coil to the points is grounded or broken somewhere. If you have a volt/ohm meter you can easily trace the problem.

Let us know what you find. You will find plenty of help here.
 
If the engine starts cold but either stalls or runs very badly after warming up ( no or poor spark) I would suspect either a condenser or coil problem. Condenser first (NAPA has good replacements).
 
Ok thank you I have a pretty good idea what to do now
So how would I make these trouble shooting tests.. dummie question
Can I use a test light ??
Or volt meter ?
 
santino2010 said:
Ok thank you I have a pretty good idea what to do now
So how would I make these trouble shooting tests.. dummie question
Can I use a test light ??
Or volt meter ?
Click to expand...

As stated before don't let the switch on more than 2 or 3 minutes without the engine running. If the points are open it's no problem because the ground side of the coil is disconnected. If the points are closed the coil is hooked up to ground and the coil becomes a big resistor and heats up like the wire in a toaster. This burns the insulation, melts the tar inside and if hot enough cracks the outer case. On a weak battery you may be lucky enough to run the battery down before damaging the coil. With a battery charger on, ignition on and points closed you could have a fire. You can see if the points are working 2 ways. First with no battery and no ignition voltage attach the ohmmeter to the coil where the ignition wire connects, ground the other lead to the engine and turn the engine by hand. When the points close the needle should move to the same point on the face as when you touch the 2 leads together. If it don't move to near the same meter position the points are dirty and if it don't move at all the points are corroded to the point they make no contact. Had a 35 phaeton 2 days ago so bad there was no contact at all. The other way is to turn on the ignition switch set your volt meter to 6 volt range and check the voltage from the ignition wire on the coil with the black lead and the red meter lead to the engine. If the points are open and the ignition switch is clean and working you should have close to the battery volts of 6.2 or 6.3 on a good battery. If the points are closed you should have right around 4 volts. This voltage is being dropped by the ignition resistor on the firewall. If the voltage with the points closed is much below 3.5 the engine will be hard to start or may not start at all. If the voltage is to high it will burn points, check the resistor. With a low battery when starting the engine the starter will pull the voltage at the coil down to 3.0 volts or less, sometimes as you let off the starter the engine is still turning and the voltage go's up and it starts. It will also start if you coast down a hill or push the car because the starter isn't dropping the voltage. G.M.
 
Last edited:
Check the insulated wire that's under the plate in the distributor that the points and condenser mount on. It's a common problem. A little worn spot on the insulation equals no start or engine stalling for no apparent reason.
 
Ok Thanks again
Everyone
I'm gonna start to run some test on it to see what's going on.
I'll keep it posted later what the results are thank you
 
flathead4rd said:
Check the insulated wire that's under the plate in the distributor that the points and condenser mount on. It's a common problem. A little worn spot on the insulation equals no start or engine stalling for no apparent reason.
Click to expand...

No insulated wire in the early distributors, Solid brass and copper.The wire started in 49. G.M.
 
It would help if the OP would be more specific on what he's working on. Early or 8BA? If a relatively new guy picks up a 239 flathead, chances are pretty good it's an 8BA.
 
I vote for the condensor failing , spent a day chasing ghost, pulling dizzy and checking point's and plugs, all for a 10 cent condensor
 
trike84 said:
I vote for the condensor failing , spent a day chasing ghost, pulling dizzy and checking point's and plugs, all for a 10 cent condensor
Click to expand...

I have seen condensers act exactly like a bad coil, work good when cold and start shorting or open ternally when hot. The easy, best most reliable way to test condensers is with an analog meter with the dial or meter face. Turn the meter to a fairly high ohm range, short the leads together and zero the meter. Take the condenser and touch one lead probe to the body and the other to the terminal lead of the condenser. Reverse the lead probes touching the body and the terminal with the opposite probes. Each time you reverse the probes the voltage from the meter charges the condenser and the meter jumps about 1/2 way up the scale on the meter face. If it don't jump or the meter pins itself the condenser is open or shorted internally. Now the condensers that jump up every time the leads are swapped looks like a GOOD one or at least it's good when cold. Now the real test to see it it's REALY good. Heat the condenser in the range of 140 to 160 degrees. This is about the temperature where if you pick it up between your thumb and pointer finger you can only hold it about 2 seconds (office hands will drop it now) now do the test again while hot and if it works you have a GOOD condenser. By working I mean it jumps just like it did cold. Condensers have been and are a problem. You don't know where most are made and have no idea how old they are. There are brand new looking ones around from the 40's that are dried out and if they work don't last very long. We use a Napa IH-200 and make it fit. On the coils with the condenser inside the back (32/36) put a brass screw through the hole where the screw held on the old condenser, put a lock washer and nut on and tighten good. Then the lead terminal ring on the screw with another lock washer and nut and tighten them. Use the grounding sleeve that come with the IH-200 to mount the condenser and grounding with the rear screw on the passenger side that holds the coil on. On 39 type coils attach the ring terminal to the little brass tab on the bottom of the coil and mount the grounding sleeve on the passenger side coil hold down screw. We never had one of these condensers fail in 15 years. You can also carry a condenser with a wire from the body with an alligator clip on the other end and clip this to the engine and another wire off the terminal of the condenser with a clip and clip it to the coil wire terminal to get you home if the condenser is a problem. G.M.
 
Hello again all ...
So I ran a few test and got ok results .
Tsted ignition it's good ..
Tested coil by it self gave me 1.3 ohms
I heard online you can test the coil out and tip of the contact points with your meter got 6 volts across did I do this test correctly? ??
The points don't look burned out but how can I tell???
The ground wire that goes from the coil to the ground of the distributor is ok as well..
The plugs got carbon built up but I don't think that could be my spark issue right???
I'm kinda stuck now from here what should I do next ??

Thank you
 
The way I test for spark is remove the dist wire center and place 1/2 from ground metal. Turn key on and have points open then take a screw drive and short out should spark every time. OR turn engine over with points with air gap .015
By turning over it sparks to every cylinder, not just one plug doing away with 2 turns per cylinder. Best replace both points and condenser. Don't leave key on for more the few minutes.
 
Santino,
Please add your location to your profile. Might be someone nearby that can take a peek at your problem.
Just hang in there and follow the advice of these knowledgeable folks and you will get worked out. We have all had these head scratching moments. Enjoy the "adventure".
(I leaning towards a condenser problem)
Keep us posted.
 
You must log in or register to reply here.
Back
Top