Hi All,
I went to start my 1995 jeep wrangler 4 cylinder after it sat for 4 months and to my surprise it wouldn't start. The engine cranked over but I had no spark on my distributor wires. I replaced the coil, distributor cap and rotor, plug wires and plugs. I figured it was the coil and replaced the rest because I had a feeling something else in the system would end up having problems in winter conditions. I have 12 volts going to the ignition coil during starting. How should I proceed to find where the problem is?
Thanks

When you said you had no spark on your distributor wires, do you mean that if you pull a wire off of a spark plug, and bring it close to the engine block, there is no spark when you crank the engine?

If you have no spark there, then pull the center wire out of the distributor and hold it close to the engine block. If you get no spark there, then the coil isn't firing.

The 12 volts on one aide of the coil with ignition "on" doesn't fire the coil. That only allows the field to build up. It's the ground being removed from the other side of the coil that creates the big spark.

To fire the coil manually. hook up a temporary jumper wire to the "low side" of the coil (the side opposite that owith the 12 volts). With a friend holding the center wire of the distributor close to the engine block, temporarily touch the other end of the temporary jumper wire to ground. That should create a spark. he engine doesn't have to be running, as long as the ignition switch is on. If you get a spark at that time, it means that the ignition system isn't removing and replacing the ground on the coil when it turns over. That means that either the distributor or the ignition control box is bad. (or some associated wiring). Of the two, the ignition box is more likely than the distributor to be bad.

I connected the coil as described above and fired it manually. It worked properly. So the problem must be with the ground then. Is there any way that I can pinpoint where the problem may be? How can I tell if it is a distributor problem(already replaced cap and rotor) or computer/sensor problem?

Thanks for the help

I have another idea. I had the same problem with my 91 YJ after having the 'parking brake pedal assy' recall done on it. There is a ground wire that comes from the fuel pump and mounts up under the dash. When they took the old bolts out, they laid the ground wire aside and never reconnected it. When I went to pick her up from the shop, she would crank and no fire. I replaced the CPS and coil with no luck. Was about to replace the computer module thingie when I found this forum and asked around and found that it was low fuel pressure causing the computer to not allow the spark and hence no fire. This was what brought me to this forum and I love offering that suggestion due to it worked for me when noone else had an answer. The wire on mine is DARK green with a yellow stripe or something like that.
Could be a shot in the dark, but ya never know. We all learn from eachother here. Let us know what you find!
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Then you prolly need to replace the thingy in the dist that took the place of points. I have not been inside of the 4 banger but there will be a thingy in there that is lectric and does go away from time to time. It can be checked with an ohm meter it is called the dist "pickup".
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

Replace your crankshaft position sensor. If it has weakened, it cannot read the the #1 cylinder and allow your computer to set the firing. Very common problem in most vehicles from 88 and up.