I have recently redone my 98 Dodge Ram 1500 5.9L, paint, rebuilt motor that bored over .30, new transmission, 4.56 Gears, whole 9 yards. First week I got motor installed it blew a head gasket, so we put a new set of heads to be sure it didn't burn any valves etc. and ever since we have had a misfire issue, even before the new heads. We have triple checked fuel pressure, and timing on a snap on code reader and live data tool. Checked compression, and everything but still seem to have this misfire I'll show in a video. Recently we have replaced fuel injectors, ignition coil, distributor, rotor, and cap, brand new plugs and wires(OEM Champion plugs) replaced all the O2 sensors, has had new gaskets through out the motor such as plenum, head, intake, etc, also done a PCV valve, new computer(ECU), crank sensor, thermostat, temperature sensor, checked all vacuum lines, and out of all this the only code we can get the computer to throw is something about a "crank to cam" I forgot the number code it gave us. You can physically feel the roughness of the misfire and hear it from the exhaust. I've about given up, and researched asked around to everyone I know. Anyone with any advice or help would be greatly appreciated. Here is the video

 

Wow. Don't take this wrong, but you blindly threw parts at the issue.

One piece of the puzzle you did not mention is the Camshaft Position Sensor (CKP). If it is cracked or the pigtail is damaged, then a misfire can manifest. When I rebuilt the engine in my old 5.2L a misfire was one of the first issues to appear. It turns out the connector for the CKP being dirty (dirt and grease) will cause the issue.

I've spoken to other people who've had misfires on different vehicles. One person stated he and a friend were chasing one for weeks until they pulled the CKP and checked it very carefully. Turns out it had a faint, hairline crack that ran from one side to the other.

 

Exactly Camshaft Position Sensor is the first thing you should do.

 

Sadly yes we were throwing parts, according to symptoms, also always looking to learn so no offense taken. Thank you for the input, that'll be the first thing I'll check when I get off work! Is there anyway to inspect this or change this part without affect the angle or timing degree on the distributor?

 

IIRC, it has a notch/tab so there is only one way to install it. My advice is to unplug the pigtail, remove the cap & rotor, and then remove the CKP. Examine the harness and connector very carefully for damage. After that, examine the the sensor itself. A magnifying glass or jeweler's glass might come in handy.

Other than that, because timing is controlled by the PCM, it is possible something is out of whack, but turning the distributor won't make a difference.

I can't remember the specs, but the rotor should be pointed to #1 cylinder TDC. Hopefully, someone who knows will post.

 

Ran across your post looking for help with vacuum lines.

I have a 96 ram 1500 with 5.9L Was having random misfire issues after a rebuild.

Finally ran across TSB 18-48-98 which discusses misfires cause by spark plug wires crossing and too close. The bulletin gives you a routing diagram to separate the wires. I just did this and misfires at idle and park seem to have subsided. I will test it out on the road tomorrow. Can't hurt to take a look at where you placed your wires.

BTW I would like to have serious discussion with the genius who put the distributor behind the engine and under the cowl making it impossible to see anything much less get your hands back there.

 

This is an old thread and the guy who originally posted isn't around anymore . It's too protect it from water

 

The magnum motor is based off the LA motor that came out in 1964. The design didn't change that much but since then the aerodynamics of the vehicle body did so that's why the dizzy is back there. You can use a top side creeper or lay on top of the motor and use a mirror to see things. And if you replace the stock wires with good 8mm ones or larger cross jumping will most likely be eliminated.