1970 Jeep Cj5 Starting Issue, Maybe Distributor Cap/System?

  Hi, my name is Tack, I'm 17 and live in Kansas City. I drive a 1970 Jeep Cj5 which I've dubbed, "The Red Bucket" because, well, it's red (duh) and because of its complete lack of doors, top, roll cage, and a folded down windshield. Anyway, I drove it to work about 2 days ago. Started fine, drove fine, no problems. When I came back from work it started fine. As I drove down the parking garage, the engine, a Buick Dauntless v6, just stopped. it didn't really even sputter either, just stopped, leaving me rolling down the garage with no power steering. Now, at this point, I just though I had flooded it, happens all the time so I figured, "Hey, no big deal." If I've flooded it good, I normally only have to wait about 10 minutes till it springs back to life. However, after 10 minutes, 20 minutes, and 30 minutes, I was forced to call home to get a ride. Now I am a little worried, but I shrug it off thinking I have just flooded it really, really, really, bad. I drive up the next day to try and start it again, but only to find it in the same condition as the day before, starter turning, lights working, but still nothing. 
 Now, my knowledge of cars really doesn't go any farther than YouTube. I'd consider myself a "car guy," but I am no mechanic. That being said, based on my knowledge of distributor caps, my current hypothesis is that for whatever reason my distributor cap is not functioning. To go into more detail, there is starter noise, but no vibration or noise from pistons beginning to move and fire. Also, roll starting did not work and I am not out of gas, good thoughts though. Any thoughts, questions? 
 I'm hoping I've provided enough information, if not let me know. Thank you very much,


What led you to suspect your distributor cap? Have you tested for spark? Fuel?

@shadowfax I suspected the cap for two reasons. The first, and main reason, being something similar to this has happened before, in that instance the cap actually broke though this time there doesn’t appear to be any damage with the cap itself, making me wonder if its not the cap per say, but just the distributor system in general. Second, I am trying to narrow the problem down by looking at the simpler stuff first, then moving to something more complex.
Now, as for your suggestions, I have not checked, thoroughly, the fuel or spark. I did clean the plugs at the beginning of winter and I haven’t had any problems with spark plugs before, though you do bring up a good point. As for the fuel, are you implying maybe there is a bad fuel line? Would either of these be likely to happen suddenly or are these issues that happen over a stretched period of time? I ask this only because I hadn’t notice any problems with either of these before, however I wasn’t watching closely for them either. Thank you very much!

I can’t imply anything at this point because we don’t have enough diagnostic data. One area in which shadetree mechanics (and some professional mechanics who should know better) get into expensive trouble is when they toss parts at the car before they’ve conducted a proper diagnosis of the problem.

It COULD be the distributor cap, but if it isn’t then you’ve just wasted money and time putting a new cap in. I’ve seen people sink hundreds and in some cases thousands into the guess approach, so I tend to not be a fan of it in deference to your wallet. :wink:

Testing for spark is easy: pull a spark plug, hook it to the wire, lay it on the engine making sure the electrode is not touching anything and making sure the threads are touching bare metal on the valve cover, make sure it’s in some sort of shade (better visibility), have someone crank the engine, and look to see if it’s sparking. If it’s not, then you can move backwards from there until you find where the electricity stops.

Fuel is also pretty easy. Remove the carburetor lid, and the air cleaner. Have someone crank the engine and pump the throttle while you peer down into the carburetor throat. See fuel squirting? No? Then you have a fuel problem and can start working backwards from there to find where the fuel stops.

Alternately you can pop the fuel line off the carb, stick it into a glass bottle, and have someone crank the engine to see if gas squirts out.

I would recommend you figure out if you have spark and fuel and report back - we can start figuring this out from there.

Take off the air cleaner and look inside the carb as you pump the gas a few times. If gas squirts out then it’s probably ignition, or electrical power to the ignition system. If no gas, then you know you have a fuel blockage somewhere (are you sure you have gas in the tank?).

@shadowfax Ok, both of those seem simple enough. I’ll make sure to test them, because yes, I do agree with what you said about “guessing and checking” and I want to follow any leads before trying to fix something. Thank you so much!!

@texases Ok, will do. I have had a TON of trouble with the carb from either ton much air or to little fuel. Thank you

When a carbureted engine stalls instantly as though the key were turned off it is usually not a fuel problem. When attempting to start the engine, as the starter cranks the engine, does it seem that it is starting but when the key is released the engine is not running? If so the resistor has failed. But open the hood and have a look at the coil wire, remove the cap and closely inspect the cap and rotor and contact points. Then with the key in the RUN position check for voltage at the coil (+) terminal. No voltage there would likely be the result of a failed resistor.

I had a '70 Jeepster with that V6 Buick motor. As a new car it was junk. The ignition system was very sensitive to moisture. On a rainy, humid day it just wouldn’t run. I’d suspect a few things, the coil could be shorted out. Check the ballast resistor. A bad resistor sends to much current to the coil which burns out the coil. Check the points, and change the condensor. Bad plugs would cause misfires but not the total shutdown you have now. A bad cap is the same, you’d have misfires and backfires not a complete shutdown.

A distributor cap will seldom cause any problems unless it’s cracked badly, carbon tracked, or has become saturated with moisture on the inside.

You might take a look at the contact points in the distributor. Those need to be gapped correctly and a drop of lubricant put on the distributor cam lobe. The lube will prevent the points from closing up over time.

I can explain the point setting procedure if you want or it could be dredge up on the internet. Gapping the points is best done with a dwell meter which I assume you do not have. Sans dwell meter, you need a feeler gauge or as a last resort; gap them with a debit card, etc.

Are you still using points ignition? If so, that’s the place to start looking…next, investigate “dropping resistor”…Virtually all cars with points had one in the positive coil wire somewhere…

You can by a “Test Plug” spark plug that comes with a clip attached so you can attach it to any metal part on the engine. Then you connect one of your plug wires to it and crank the engine while you watch it’s large and visible gap for a spark…This lets you test for a spark in a matter of seconds. An inexpensive and handy tool…

Pretty Jeep though. :smile:

One thing I would add if it were mine would be a roll bar. Just in case.

I second the roll bar. Jeeps can roll pretty easily in an avoidance maneuver or to fast of turn.