i have a 98 2.0 dohc neon that has no fire or fuel ive checked fuel pump relay, asd relay, fuel pump fuse , coil pack , even changed the crank shaft position sensor still no fire . The book i have for the car says the crank shaft sensor and the camshaft sensor should have 8 volts going to it when the key is on, it doesnt have the 8 volts to either sensor. Any and all ideas would be appreciated. Also i was speaking with someone at a local auto parts store who told me that if the computer detected no fuel pressure at the injectors it wouldn't allow the ignition coil to to power up is this true of bs.

 

All the sensors do feed into the PCM. It is true that if the PCM does not receive a proper signal from the fuel system it will cause the system to not fire. Now if your fuel system is functioning properly, then it could be your PCM that is bad. The ONLY way to test for a bad PCM is to take the entire car to a shop that can diagnose a bad PCM while it is in the car. It cannot be bench tested (I got that straight from the head mechanic at my local dealership).

I have heard that this problem can also be caused by a) bad grounding straps to the car's frame and b) by having shorted wires to one or more sensors (particularly the crank and cam sensors and the O2 sensors. Good luck.

 

i traced the orange wire from the camshaft sensor and the crankshaft sensor back to cpu and ohm'd them out and they are fine. Just not getting any voltage from the cpu when u turn the key on . Also when your turning the key on i remember the check engine light lighting up before u start the car , its not coming on at all. Would that mean the cpu is dead , also tried getting the cpu to kick out the trouble codes on the dash by on,off,on,off,on and its doing nothing. Im leaning towards the cpu being bad

 

just found a place on ebay that is located in florida that will program a rebuilt pcm with my mileage and vin number for 159 dollars and they have great feedback . Probaly going to give them a shot

 

the "check engine light" should flash 5 times with key on. If not, thats a good sign the PCM isnt responding. hook a scanner to it. if you get something like "ERROR! unable to communicate" your PCM is most likely bad.