As of a week and a half ago, my 95 Dakota (3.9 4x4 manual tranny) started having some weird electrical issues. I was driving down the street a few miles from my house, after driving ~30 miles, when all of a sudden it died out and wouldn't restart.

I could smell fuel in the engine compartment, so i was pretty sure it wasn't getting a spark. I called dodge, they told me to replace the cam position sensor and the crankshaft position sensor. We did, but it didn't solve the problem. It would now start up, idle for 2 minutes, then die. We went through the electrical system, made sure every ground was perfect, and when we fixed the ground on top of the alternator block, everything was fine...

...for 3 days, then it died again pulling into my driveway, and wouldn't restart.

I got it towed to my mechanic, but when it arrived, it started up, ran fine, and then died after a few minutes. They (and i quote) "jiggled some wires," and the car was fine. Drove it home last night, was fine.

I went to start it this morning, and it ran horribly rough, threw a CEL, and died, but was able to be restarted. I drove it to the gas station, with it running rough the whole way, (CEL on the whole way) stopped, filled it with gas and a fuel additive, and it ran fine when I restarted it. No more CEL

3 miles later, started running rough again. drove it to my mechanic, and when I got there, it ran fine again. No CEL. Drove it 70 miles to work this morning, ran fine the whole way.

The next morning, it started, ran rough, and died less than a mile later, unable to be restarted.


It's obviously an intermittent problem, and it's annoying the ***** out of me.

Thus far I've replaced:
wires, cap, plugs, rotor.
timing chain
water pump, belt tensioner, hoses (unrelated, but these were done one day before these electrical problems started)
cam position sensor
crank position sensor
misc worn wires

Any ideas?

 

Replace the hall effect pick-up plate in the distributor might be it. My 90 kind of did the same thing and that was the problem.

 

The camshaft position sensor is the one in the distributor, which he said he replaced.

As far as the "misc worn wires," do you know what the wires went to? If you don't know what they went to, do you know where the wires were located and what color they were?
It's really looking like this is either a bad new part (unlikely, unless you changed them out with unknown-quality used parts), or, most likely, a wiring issue, which is a recurring problem on vehicles that are older (andon older aircraft, like I work on [&o]).
I would start with wiggling wires at the PCM, crankshaft position sensor, and camshaft position sensors, perferably with the engine running, and see if it makes a differance. For instance, if you start messing with the wiring at the camshaft position sensor, and than the engine dies or starts running rough, you may have found the problem (or at least part of it).

Another thing, go through the connectors under the hood and make sure they are all in good shape, free of corrosion, and fit tightly. My grandpa was having a problem with his van running rough and whatnot, and it turned out to be a corroded connection at one of his fuel injectors.

Also, what was the CEL for?

 

the worn wires replaced conist of replacing all of the body grounds at the firewall, the grounds at the alternator block, and the power break block. There was one frayed wire coming from the ECU, but i didn't check where it went. just replaced it where it was bad.

All of the parts i've replaced have been brand new.

The recent CEL was for a bad throttle position sensor. That fixed the running rough problem, but not the dying and not-starting problem.

thats for the help. any other suggestions?

 

Ok, now the questions start:
When it dies and won't start, answer yes or no to the following:
1) Do you still get spark when cranking
2) When you turn the key to the "ON" position, can you hear the fuel pump turn on for a second or two (have a friend stand next to/lay-by the fuel tank if its hard to hear)
3) Have there been any constants in when this happened (weather, engine speed, etc)

I will suggest hooking up a fuel pressure gauge, and monitor that. You may also try replacing your relays (I believe you have both a fuel pump and automatic shutdown [ASD] relay, those are the ones I'm talking about; their in the black box by the battery/windshield washer reserviour under the hood).

 

1) i don't get a spark when cranking. pretty sure it's a spark issue.
2) you can hear the fuel pump, and smell fuel in the engine compartment when/after cranking. dont' think it's a fuel system issue.
3) this has almost always happened when it's particularly cold outside, less than 25 degrees or so. other than that, it's happened when the engine is both warm and cold, rainy and dry.

again, this is an intermittant problem. it works sometimes, runs perfectly. other times, no spark, no start.

 

Ok. Get multimeter (or something that can measure ohms) and do the following:
Disconnect the battery
Connect one lead of the multimeter to the dark green/black wire (typically this color) at the ignition coil. Than, remove the ASD relay. At terminal 87 ofthe ASD relay connector (the output, usually the pin numbers are stamped on the bottom of the relay) connect the other lead. Test for resistance, it should be lvery low (not many ohms). Wiggle the connector at the coil and see if this changes anything.
If all checks good, put the relay back.
Now, disconnect the PCM connector, and probe pin 19 (it should be gray) of the connector to the other wire (same color) at the ignition coil connector. Again, resistance should be very low. Again, wiggle the wires at both connectors and see if this changes anything.

Another thing you can do is test the coils primary and secondary resistance. Primary resistance is basically testing the resistance where the coil secondary cable (the one that runs from the coil to the cap) connects. Just put the two leads of the multimeter at differant places on the metal piece, and the resistance should be less than 1.5 ohms. (about .6-1.4). Secondary resistance is the resistance through the coil. Keep on lead of the multimeter on the "coil output" and test resistance from each of the two pins. Resistance should be between 11,300 and 15,300 ohms (mine was 12,900 ohms).

 

I brought the truck to the mechanic who had looked at it in the past at the end of last week. i forwarded him what you suggested, he'll take a look at it.

I'll keep you posted with his feedback.

Thanks again for the help.

-Tim