Dodge Repair/1994 Dodge Dakota 5.2L engine dying
QUESTION: I have a 1994 Dodge Dakota ext cab with a 5.2L 5 speed trans. Late last week, I started having a problem, sometimes it would just stall for no apparent reason, and usually it would restart fairly easily, but by Friday, it was laboring at idle like the timing was way off, idling really rough, knocking like the ignition timing was way off, little to no throttle response and then it would die and be difficult to impossible to restart, but after a few minutes it would usually restart. I know that the cam position sensor and the crank position sensor can cause these symptoms can cause these symptoms, so I started with removing and inspecting the cam sensor, went ahead and replaced it, and the problem persisted, so I replaced the crankshaft sensor. when I removed the old sensor, I saw a crack down the length of the sensor, so I thought I had found the problem, replaced the crank sensor and thought, "cool, life is good...founds the problem"...not so quick...the symptoms came back after a few miles, returned the sensor as defective, bought another one, put it in, when I drive 7 or 8 miles, it start acting up again. took it out and it was pretty hot, as I would expect, but I took it and cooled it down with some water and put it back in, and voila, started right up, ran for a few minutes and it quit again, same symptoms, took that one back and got a refund and bought another from another source, a BWD part as was the last one, and I still have the same problem. could something else be causing this that I am overlooking, or am I the unluckiest man in the world at getting bad parts? I don't know where to look next. In the past two years, I have changed every one of the sensors except the oil pressure sender along with the fuel pump, distributor cap and rotor, the spark plug wires and the spark plugs. It ran very well until this. This truck has 237,xxx miles on it was still getting 15+mpg in town and 18-20 hwy at 70-75mph. help, I need my truck healthy again! Maybe if we can figure this out it will help someone else who is having this problem. Thanks in advancefor your help.
ANSWER: Hi Glenn,
I just found this question in the "pool" to which it had been referred by Kevin. When you asked me the question you didn't mention the heating up of the crank sensor. That could cause an ignition timing problem. The two possibilities to consider are that the sensor bolts are not tight enough so heat is not being conducted away. The bolts should be at 70 inch-pounds.
The other is to measure the resistance between the pins for the 5v supply wire and the sensor ground which should show no resistance (wires to those pins are violet/white and black/light blue). That is what I found about the 5.2L sensor. You would believe there would be an 11 fault code were that the case, however.
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QUESTION: I checked the wires you soecified, I found continuity one direction and no continuity the other direction. There are three wires; an orange wire, a black wire with a blue trace and a white wire with what appears to be a purple or violet trace. The black/blue wire shows continuity to ground, so I assume it is ground. I did not find continuity both directions, so does that indicate there is a diode or other sort of semiconductor involved?
ANSWER: I have the '95 wiring diagram for the 5.2L as used in the Ram models. The orange wire is a 5 volt wire, the black/blue trace wire is the ground wire, and the violet/white is likely the crank sensor signal wire (though on this diagram the signal wire gray/black). They come from pin 5, pin 3, and pin 8 of the number one plug of the pcm. What I mentioned earlier about "no resistance" at the sensor proper (with the plug disconnected) refers to a reading between the pin that is connected to the orange wire and the pin that is connected to the black/blue trace wire and "no resistance" probably means infinite resistance rather than 0 resistance, though I can't be certain.
I don't know what you meant by "I did not find continuity both directions..." as it is not clear which wire you are speaking about and where you were placing the probes to measure continuity". I can't tell for sure what is the electronic parts of the sensor or to which pins of the sensor they are attached.
If you have not solved the problem by replacing the sensor then I would believe that it is not the cause. You could check the continuity of the wires between the sensor plug and the pcm plug, and shake the harness while you do the check. Otherwise, I have no other ideas as to what to do without there being a fault code. You didn't tell me if the check engine light is showing a 55 code, and nothing else, or that it isn't working.
If you would rate my answer/nominate me I would be most appreciative.
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QUESTION: Hi Roland,
Every time I have checked the codes, all I have gotten is a 12 and a 55. I did check voltages on the sensor with it plugged up to the harness and the truck running, after it had been idling long enough to get warned up good and the orange wire was reading 9.16v to gnd with a Digital multimeter, the grey/black wire was reading .45v to gnd. I will go back and check resistance readings on the sensor itself. and ai will check for continuity back to the PCM. If I dont find a problem, then its possible that there is an intermittent problem in the PCM I would think since everything that sensor handles either originates in the PCM or inputs to the PCM. Do you think I am pursuing the right path, that I'm thinking right about this?
I wish I had the '94 manual rather than the '95 so I can't verify those wire locations on the pcm. I can't say either that it is likely the pcm, for lack of any code for it. But try to check things out when the engine is in the fault condition, including the egr valve. Maybe you can find a '94 pcm used from a wreck.