So i have a 93 dodge d150 that will crank but not fire. I have changed the coil, pcm, distributor, cap, rotor, sensor under the distributor, crankshaft posistion sensor, speed sensor, and have the another asd relay on order. I chased wires and everything looks to be ok no broken wires. The crankshaft sensor is not an oem one. this is the 5.2 318 engine. Fuel pump has also been changed. At this point i am at a loss, any help would be great thanks.After all the testing ive done it seems like the pcm will not provide the ground. Im getting a code 11, 12, 42. The 42 is new from the other night but that may be from me trying to jump power. I have an asd relay im picking up tonight.

 

See if you are getting power to the coil for three seconds when you first turn the ignition on.

Does the fuel pump prime when you turn the key on?

 

i get the initial power to the coil when you turn the key on yes, i can hear the fuel pump as well. Then the power drops out to 0. I will have the new asd relay in it tonight hopefully that will fix it. will keep you posted.

 

I can smell the gas so i know im getting fuel just no spark.

 

Then your ASD relay is doing its job, and changing it won't change anything.

If you subsequently crank the engine, do you see power at the coil again?

 

 

If you don't see power while the engine is actually cranking, regardless of how long ago you turned the key, that implies the PCM isn't seeing the engine turning. According to theory, it will use the crank sensor, OR the cam sensor to make that determination, but, I don't think in reality, it actually works that way. My supposition is, if the PCM doesn't get a signal from the crank sensor, it simply ignores anything it gets from the cam sensor, and disables the ASD relay. So, investigate your crank sensor. Verify you are getting voltage TO the sensor, and see if you are getting anything out of it. (test light will be fine for that. It'll just blink dimly.)

 

 

It uses both, The engine on initial start needs to see the crank signal(so it knows it's turning) then it looks for the cam sensor(so it knows where the engine is (cylinder #)) before it fires the coil. The crank needs to make one complete rotation before this happens. I also think the pcm is not seeing the crank signal so further investigating is in order.