I recently purchased this truck and over the last few months it has slowly got worse. It would randomly stall out, cylinder 3 wouldn't fire (constant misfire) so I did the tune up on it and it still wouldn't run right. And since I changed out both valve cover gaskets it has not ran. No spark at coil. Checked the asd wiring and it's good. Got power to the coil but no control, but power would only stay on for a few seconds will cranking. So checked both power and ground (loaded test) at CPS and both checked out. Checked signal and nothing. So replaced CPS with a new one and still no signal coming out. Ran codes and got code 11. Before and after I replaced CPS. So I warranted the CPS and got another new one and same issue. Decided to check for injector control and got nothing at pcm or at injectors. But have power while cranking. From the Haynes manual it sounds like the CPS is there to provide spark and to let the pcm know that it's running and the distributor pickup is there to turn on the asd relay and provide a sync notch for the fuel injectors to fire. It has all new plugs, plug wires, cap, rotor, coil, and distributor pickup. I'm at a loss on this truck and I don't know to even look for. Check engine light is on when the key is on. Which to me means that the pcm is alive. All power and grounds at pcm is good. I really don't want to pull the transmission out to look at the reluctor wheel for the CPS. Any ideas?

 

Check the wiring and vacuum hoses that runs between the intake and the valve cover. I think you must have disconnected something without realizing it when you put in new gaskets.

 

All the wiring and vacuum lines are in place. Is it possible that the reluctor for the crankshaft position sensor is broken? How many notches should it have? I'm thinking it should have 6. And if it does then I should have a signal ever 60° rotation of the crank, which I don't. And once in awhile when I'm spinning the engine over by hand slowly I can hear the fuel pump kick on for a second.

 

Well, they're not 60* of engine rotation apart; the Dakota 3.9 is an uneven fire motor. (IIRC, it's either side of that.) There's also more teeth than that. But yes, you should be seeing pulses from the crank sensor.

RwP

 

Rechecked the basics again on the truck. And now I'm only getting power to the coil when I first turn the key on and for about a second when I crank it over. What am I missing? It has a new crank sensor, and ignition pickup. All connectors are tight and plugged in. Asd splice has been fixed. Power and ground are good to the crank sensor.

 

You should see power at the coil for about three seconds when you first turn the key on. (hear the ASD relay click.) After that, the PCM needs to see the engine turning to power things back up. (crank sensor.) Having a friend help ya with checking voltages and such makes this exercise a LOT easier.

ASD provides power to the injectors as well, so, can check for power there while cranking to.

 

I'm only seeing power at the coil, and injectors for maybe a second while cranking. I can hear the relays click on and off. I still have code 11. Which I haven't disconnected the battery yet to see if that code comes back or not.

 

PCM isn't seeing the engine turning. So, possible bad crank sensor.