Ok. I am in the process of hooking up a tach in my jeep. I started it up to make sure i had the right connections on the bundle to the cluster. I did and turned the jeep off. I took the retaining clips off the bundle and placed wires in with the ignition, Ground, and tach reading. I then went to start the jeep and its dead. No spark. There is no spark from the coil. 12v into the coil and only 6v out of it. There is also 12v to the ignition and ground wires i got off the bundle. So, the coil is dead. I got a new coil and it is dead as well... taking in 12v and putting out 6v. I am in china and it is very possible that the "new" coil i got is a cleaned up dead one. Im going to go exchange it on saturday for another one. Posting here to see if anyone has any info on this. I am checking the voltage by putting one on the negative of the battery and the other on the post on the coil. Am i doing it wrong? With the ignition on i can touch the coil and feel nothing... no sparks or anything when coming in contact with a ground. Ideas?

 

Hey guys, if someone can do me a favor and go check the voltage going to the coil... if you have a volt meter this will take you 5 seconds... just pull the plug off and check the voltage. im getting 12V... should it be different?

thanks!

 

I think its supposed to be around 12v

 

it has to be 12V... this is pissing me off... lol, it has to be a bad coil... it has to be. can't figure out what else it could be...

 

OK... so, correct me if im wrong, the coil takes in 12V but needs the temp lack of voltage so the field can collapse causing the discharge of 10-15,000 Volts to the distributor. this happens when the breaker points in the distributor are opened (by the cam) causing the coil to lose voltage and producing the high voltage 'pulse'. im pretty sure im not getting that, so the coil is never losing voltage thus the coil never produces the high voltage discharge. Please correct me if im wrong. (i have the 2.5L with carb)

so, i need to check/clean the breaker points in the distributor and make sure everything is operating as it should. What about crank sensor? i have read that if it is bad it hinders the spark but im not sure what system they are talking about (im guessing the fuel injection ignition system is a little different then mine)

thoughts?

 

You don't have points. You should have a pulsing ground at the negative wire on the primary coil plug.

 

where does it get the pulse from? i cannot find a control module anywhere... where should it be located?

 

From reference signals from the crank sensor and pickup coil in the distributor. Use a 12v test light and check the primary gound wire on the coil, crank the engine over and see if the light flashes. If there is no flash but the light stays lit, you have no signal from the crank sensor or pickup coil. If there is no light at all you should look for an open in the ground circuit. The engine ran before you installed the tach?

 

it ran just fine... the tach is not installed yet, just the 3 wires off the bundle. i will check for a pulse with a light. is there any way to test the pick up coil or crank sensor seperatly to see which one is out? got any pictures of the crank sensor location? all i have heard is it is on the top of the bell housing. sounds impossible to get to. lol.

thanks for the help!

 

I cleaned the contacts of the "points" in the distributor, cleaned the bundle connection to the distributor and pulled the wires i put in the bundle and it runs great again... im pretty sure it was the wires. i guess i crossed something. oh well, thanks for the info guys!