Trailer Park Ninja
NAXJA Forum User
- Location
- Reno, NV
First and foremost let me apologize for the length of this post, I wanted to fit in as much detail as possible. I do consider myself fairly electro-mechanically inclined and like to fix things without the cost of a mechanic. However I am at a loss.
Let me fill you in on the vehicle at hand. I have a 1998 Jeep Cherokee Sport 4WD with; 6-Cyl. 4.0L, fuel injected, automatic transmission and a command-trac transfer case.
So on with the problem. A few days ago I drove into work with nothing wrong, the Jeep was not acting up in anyway. However when I went to start it up to leave for lunch the engine would not fire. It would turn over with plenty of RPMs. So the first thing I checked was the distributor cap (had been wet and cold for a few days leading to this). I could not find any cracks and or carbon traces on the cap. Next logical thing for me was to check for spark. Took plug wire off cylinder number 2 and held it near a "ground" point (as a friend cranked the engine). No spark was reaching the ground. I then replace that plug wire and pulled off the coil / cap wire off of the cap, and aging held it near a ground. And yet still no spark.
I then picked up a new coil from the local auto parts store (now thinking that this really was not the problem), swapped it out for the old coil and no spark. I hung my hat for the day. Went back the next day prepared for war with my Haynes manual and a bunch of printouts in hand.
First I checked the voltage in the harness connector that plugs onto the primary side of the coil, reading was a constant 4.35 volts (I really cannot see this voltage being correct) with the engine cranking over. Then on a latter try I was only getting 0.4 volts? And with my DMM set to "continuity" the ground side of the plug was opening and closing in time as the engine cranked over.
Then checked the ASD relay, testing the Ohmic value (between terminals 85 and 86 = 73.3 ohms). Next was the continuity between 87A and 30, 87 and 30 with and without 12 volts supplied. Those also tested properly.
Next moved onto the Crankshaft Position Sensor, with my tester across B and C. No resistance (open reading).
Now I am at a loss. Why am I not getting any spark out of my coil? How many volts should I be getting up to the primary side of the coil? What should I check next? I was told to test the Camshaft Position Sensor (would anyone be able to fill me in on how to test the CMP)?
Any help would be greatly appreciated.
Let me fill you in on the vehicle at hand. I have a 1998 Jeep Cherokee Sport 4WD with; 6-Cyl. 4.0L, fuel injected, automatic transmission and a command-trac transfer case.
So on with the problem. A few days ago I drove into work with nothing wrong, the Jeep was not acting up in anyway. However when I went to start it up to leave for lunch the engine would not fire. It would turn over with plenty of RPMs. So the first thing I checked was the distributor cap (had been wet and cold for a few days leading to this). I could not find any cracks and or carbon traces on the cap. Next logical thing for me was to check for spark. Took plug wire off cylinder number 2 and held it near a "ground" point (as a friend cranked the engine). No spark was reaching the ground. I then replace that plug wire and pulled off the coil / cap wire off of the cap, and aging held it near a ground. And yet still no spark.
I then picked up a new coil from the local auto parts store (now thinking that this really was not the problem), swapped it out for the old coil and no spark. I hung my hat for the day. Went back the next day prepared for war with my Haynes manual and a bunch of printouts in hand.
First I checked the voltage in the harness connector that plugs onto the primary side of the coil, reading was a constant 4.35 volts (I really cannot see this voltage being correct) with the engine cranking over. Then on a latter try I was only getting 0.4 volts? And with my DMM set to "continuity" the ground side of the plug was opening and closing in time as the engine cranked over.
Then checked the ASD relay, testing the Ohmic value (between terminals 85 and 86 = 73.3 ohms). Next was the continuity between 87A and 30, 87 and 30 with and without 12 volts supplied. Those also tested properly.
Next moved onto the Crankshaft Position Sensor, with my tester across B and C. No resistance (open reading).
Now I am at a loss. Why am I not getting any spark out of my coil? How many volts should I be getting up to the primary side of the coil? What should I check next? I was told to test the Camshaft Position Sensor (would anyone be able to fill me in on how to test the CMP)?
Any help would be greatly appreciated.