'97 Ram 1500 5.2 2wd. 153K miles. Got this truck not long ago and it had been sitting for a while. It ran terrible on the short drive home and had a trouble code of P0300 and P0351. I measured the resistance of the ignition coil and got a primary reading of 1.35 ohms which is just slightly out of spec so I bought a new coil. I also replaced the distributor cap and rotor, the spark plugs and wires, and did an oil/filter change. I cleared the codes. There was a night and day difference to how it ran and after doing some repair to the brake systems, It took it for a test ride and everything went okay until I took in onto a dirt road and tested the brakes with a sudden stop to see if all four wheels locked up in a panic stop from around 35MPH. The engine died when I slammed on the brakes and it took a long while before the truck would start (crank no start) to the point that I was concerned that the battery was going to get too low. My thoughts were at the time that maybe I had dislodged some collected contamination in the gas tank and clogged up the fuel filter or the fuel pump. But after letting the truck just sit for 20 minutes, it started and ran very well for about a week going about 450 miles. Ran great with no issues. Yesterday, I had a minor/moderate traffic accident at an intersection. Opposing traffic Dodge Neon made a left hand turn into the front of the truck dead center into my front bumper. Seriously bummed -- but the damage is really only to the bumper and although bent, the AC condenser doesn't leak and the radiator wasn't touched, The engine didn't die and thankfully the airbag did not deploy. As a matter of fact, I was able to drive the truck 27 miles to work and the truck drives and runs fine with no coolant loss or change in the steering wheel position -- you wouldn't know that the truck had just smitten a misbehaved Neon (nobody was injured). On the way home, there were a number of short instances on the interstate that the truck lost engine power while going 65MPH. Into the rural part of my drive, the engine died once at a stop light but started right up again. Finally, while driving at 30MPH, the engine died and I pulled over to a stop. I have one of those wifi interface OBDII diagnostic plugs that interface with my iPhone using the OBD Fusion app. There is no engine light illuminated in the dash but the code P0351 has come up on my phone app. Just like before, the engine cranked fine but would not start. I opened the hood and wiggled/manipulated the wires at the ignition coil and the harness that goes next to the throttle body and the engine started right up. I drove the remaining three miles home and the engine died again in the driveway.

Sorry about the long story but I want to avoid stab in the dark replies and let folks know the background here. I believe that the trouble I'm having now is the same issue as when I was testing the brakes and the engine died -- the problem has been there from the beginning???

I believe I have an intermittent wiring issue with the ignition coil. Intermittent problems are difficult to trace and was hoping someone knew of a common problem where this might be happening and the best places to look. Looking at the diagrams, it seems that the ignition coil gets its voltage from the Automatic Shutdown Relay as +12V and the PCM provides pulsed ground signals to fire the coil. The loss of either is going to make the coil stop working. I really don't want to open up the wiring harness if I don't need to.

Seriously bummed but I'll find something a little more custom for a bumper

 

Got pics of the other guy? Bet he didn't drive away......

Think I would put a continuity tester on one side of the circuit, and wiggle/pull/mess with the harness, and see if it drops. Do the same for the other side of the circuit. Also check and see if you are getting a short to voltage on the ground side of the circuit. Either will prevent the engine from running. Something else to check is the connectors on both ends of the circuit. (PCM, and Coil....) If one of them isn't plugged in good, or is dirty/corroded, would also give you a problem.

Not real sure if the 'died on hard braking' is the same problem though. May be a separate issue.

 

I don't like messing around on a running engine but I did the wiggle/manipulation of the coil wires and the harness for about 30 minutes. I got the engine to die once while messing with the harness behind the alternator where it joins the harness that goes to the fuel injectors but I couldn't get it to happen again. Maybe I can put a voltmeter on the coil's B+ by running wires into the cab so I can see the voltage while I'm driving. Its going to be a problem seeing the fault when it happens because it doesn't happen often. It could be anywhere. I'm hoping that the P0351 code is not a red herring.

 

I had a problem just like yours. Turned it to be a corroded plug they goes into the coil. Contact corner didn't work so I got a pick and scrapped the contacts until I saw bare copper. Hasn't happened since.

 

Tightened all of the ground lugs under the hood. The contacts on the coil and plug look new. Wiggle, twist, tap, thump, and yelling at the connector on the coil does nothing. Gonna drive it to work but I'll take my multimeter with me just in case. Although I appreciate the ride, the truck and I haven't established a relationship of trust yet. I would really like to find a hard cause to this issue so we can move on.

 

It'll take time for the Dodge to warm up to it's new owner just don't give up lol. Finding electrical problems can be simple or a hair puller. When it won't start see what you are missing (see if it indeed is spark).

 

Because the relays are all the same, I swapped the Auto Shutdown Relay with the one marked as "Trailer". I found one of my new spark plug wires laying on the exhaust manifold and secured it out of the way. Cleaned the wires on the coil connector and the PCM with contact cleaner and applied silicone grease to the seals. Found a few more engine and body grounds and tightened them. Drove 110 miles today without a glitch and the truck really runs wells despite looking like it has a broken nose. Gotta see what the other guys insurance company is gonna do about my bumper.