QuestionQUESTION: Hi,
I recently bought a 52 chevy with a 235 six cylinder.I have been trying to get it to start.It has'nt ran in about 2 years.I can't get fire to the motor. I replaced the distributer cap,points,condenser and put in new plugs.The car will crank over but there's no spark to the points or plugs.I'm not a mechanic and I really need help! What would you check next? Thanks, Keith
ANSWER: There are a very long list of things you will have to check, but we'll take them one by one and we should be able to get it running.
First, get yourself a voltmeter, or if that is out of the question, get a test light so you can see if you have 6 volts on the + terminal of the coil. (If you need me to tell you what a test light is, just ask, or you can go to the local auto parts place and buy one.) This is the wire that is on one of the two small terminals on the coil. The other wire goes to the side terminal on the distributor - we don't care about that one yet. Just see if you have 6 volts on the + terminal. If you don't, that explains your lack of spark. Of course the key has to be on for this check. If the key is on and there is no 6 volts there, either the ignition switch is bad or the wire from the ignition switch to the coil is disconnected or broken, or possibly the wire from the battery to the ignition switch is not connected.
When you have 6 volts to the coil, see if you have spark to the distributor cap by putting the end of the big wire (the high voltage "secondary" wire that comes from the center of the coil near the engine block - with the tip of the wire about 1/4 inch from the metal of the engine block - hold it there with an insulated tool handle or thick rubber gloves, while you have a helper crank the engine - you should see a rapid spark, at least 1/4 inch long, firing while the engine is cranking.
If you've got that, plug it back in to the center of the distributor cap, and see if you have spark to the plugs now.
If you have spark to the plugs but the engine still won't run, probably the distributor is installed wrong or the plug wires got mixed up.
If you still don't have spark at the end on the coil high voltage wire, there is probably something wrong inside the distributor.
I'll stop typing now and wait to hear back from you as to what you found so far- we'll stay on it until we have it running, or know why not. Post a "follow up" question to me and we'll pick up where we left off.
Dick
---------- FOLLOW-UP ----------
QUESTION: Thanks Dick,
I'll try these first thing tommorrow. I did notice a loose wire with a alligator clip on it under the dash. I don't know if this goes to the ignition or not. Thanks again and I'll let you know tommorrow how it went-Keith
ANSWER: Yeah, that sounds suspiciously like someone else has been trying to start the car - maybe they were "hot wiring" it.
Dick
---------- FOLLOW-UP ----------
QUESTION: Dick,
Just got home from work and tried your advice.I bought a voltage test light and the + side of the coil wire was hot.I pulled the other end of the coil wire which goes into the distributor and got my son to crank the motor and there was NO SPARK. DEAD!!! Do you think it's my distributor? I also checked the condensor and points and they all showed hot. Just for the heck of it, I checked the end of one of my spark plug wires.DEAD! The loose wire under the dash with the alligator clip on it,(the one I told you about)was dead. I sure appreciate your help on this-I would just love to hear her run! Thanks again for any help-------Keith
AnswerOK, Great, that's good progress. Yes, the problem is pretty surely in the distributor, now all we have to do is track it down.
Since you said that there was voltage on the condenser, I'm suspicious of the points setting, and the ground wire on the mounting plate for the points.
Next step is to put the test light on the wire that comes from the - side of the coil to the distributor side terminal. You already checked that point when you looked on the points for voltage, but that voltage should only have been there when the points were open, which is only a small part of the time when the engine is cranking.
Take a look at the points to see if they are closing - move the engine by hand (pull on the belts to make it turn slowly) and watch the points. If you go slowly and watch carefully, you will see the fiber rubbing block that rides on the rotor shaft pushing the points open as one of the 6 high peaks of the rotor shaft passes the rubbing block, and then letting the points close when the rubbing block is between the peaks. When the rubbing block is in the flat place between the peaks, the points should be closed, meaning the movable part of the point set is in contact with the non-moving part.
Stop the engine at that position, and check again for the voltage on the side terminal of the distributor. If you still see voltage there, something is wrong with either the points (like maybe the contacts are dirty) or the ground wire from the contact mounting plate is broken or disconnected. Or, possibly, the points are not adjusted right. They have to be set so that when the rubbing block is exactly on the peak of the rotor shaft cam, the points are open about 0.017 inches - no more, or else they won't close when the points are supposed to. That is about the thickness of an old fashioned match book cover, if you don't have a feeler gauge.
If any of these things are wrong, that is why you are not getting spark. It is also possible that the distributor itself is not grounded, but that is very unlikely, because it is bolted to the engine block.
We're real close to the answer here, just poke around with your test light and you'll find the problem, I'm pretty sure.
When all is right in the distributor, you won't see the voltage on the points or condenser except in the very small window of time when the rubbing block happens to be exactly on the peak of the rotor cam.
Once you get it to that situation, you should test the end of the coil wire for spark as I described yesterday - I think you will find a healthy spark there as you crank the engine, and we'll go the rest of the way to get it running after that.
Keep me in the loop until we finish tracking this down.
Dick
