Ok well here it is guys. I just did a head gasket job on a 1997 neon. New timing belt, head gasket, waterpump, ect. Well I started it, it ran fine for about two days and 10+ starts, no problems. However, I was out doing the finishing touches on it a couple of days later and wile it was running, I reved it a few times and was going to shut it off when it just cut out. No noises or anything (does turn over fine). At first I thought the timing belt slipped off, But after an hour I had the engine mount off and could see that it was indeed on and timing marks were right. Then I did the thing I should have done in the first place and checked my spark. No spark. I was hoping it would be something simple, but so far nothing. I put a volts meter on my coil leads (not green/orange) and I am not getting anything into it. So I know that my coil, plugs, and wires are good. I replaced the cam pos. sensor, had the crank sensor checked (good) and I got a OBD II scanner for christmas and, guess what? It isnt throwing any codes!! Not a one. I have gone over every inch of wiring in the car, I know that it dosent have anything to do with the ASD relay because the fuel pump still works and the injectors are firing. I have narrowed it down to three things after studying the schematics: 1. PCM 2. microfarad capacitor (not sure what it does) 3. Pigtail to the coil (I dont think so but a possibility). Does anyone know exactly what the capacitor does? The other reason I think it is electrical and not mechanical like a wire is because it shut down wile it was running and it wasnt hot enough to melt anything and the way it cut out I think it was the PCM. Has anyone everhad any experiance with this?? Please help I am 14 and this was my first head gasket job on my sisters car and recieved no help, my father lives in florida. Anyone with any info will be thank with much praise!!! THANKS

EDIT: Ok. I went to the scrap yard last friday and got a pcm. It didnt work so I started playing around with it and guess what I found out, I was testing the pcm wrong! It was confusing in the haynes manual because they had a 95 and they changed the coil wire in 96. I was putting it on the blue/tan AND the black/grey, instead of one at a time with the other probe on the positive battery cable. When I would crank it over the light would rapidly flash then stop. This is what it is sopposed to do. So now I know that it is either my green/orange 12v supply or the coilpack itself is bad, but I doubt it because I am getting about 11.50 resistance on each opposite terminals. I would have checked the 12v supply, but I still wasnt sure what each wire was untill I really looked at it, and sadly that was after I decided to take out the pcm-coil wiring. O well I have 70 bucks credit at the junkyard for parts so I will just get all those things along with a microfarad capacitor, pigtail, coilpack, and wiring. I guess I still have alot to learn only being 14, but what I think I will do when I get the parts tomorrow instead of hooking the 12v supply up to the coil from the ASD relay, I will put a jumper wire straight to the pigtail. I know I should have done this first but I didnt realise what exactly each wire is untill I got a cappichino and sat down and really followed and studied everything. Correct me if im wrong but Im pretty sure that green/orange is 12v supply, blue/tan is secondary high voltage, and black/grey is secondary low voltage. Well now that I have it narrowed down, I think I have it but I wanted to see what you guys had to say first. By the way I would have the parts today but when I got to the junk yard to get the parts they were closing so I only had time it get a store credit, so I will have to get back out there tomorrow. THANKS!!

 

so wher along the ignition setup do you first notice no voltage

 

Its not that I noticed no voltage, I am not sure at the moment because like I said, I have part of the harness apart so I cant see if I am getting voltage to the green/orange wire.

 

Sound like your learning a lot (if it was too easy what would you learn?)

One word of caution: if your going to jumper 12v to the green/orange be very careful not to short it to the black/grey and blue/tan or you could be back at the junkyard looking for that pcm you returned.

Your right the green/orange is 12v supply to the low voltage primary of the coil. There are actually two primary coils one end of each is connected to green/orange terminal and the other two ends connect one to the blue/tan and one to the black/grey terminals.

There are also two secondary or high voltage coils one connects to plugs 1 and 4 and the other to plugs 2 and 3.

When the pcm grounds the blue/tan or black/grey leads it produces spark in either plugs 1 and 4 or plugs 2 and 3 depending on which wire is grounded. With this setup the plugs receive spark both on the top of the compression stroke as well as at the top of the exhaust stroke. The spark on the exhaust is not required but this setup requires a 2 coil pack vs. a 4 coil pack and less complicated pcm switching.

Good luck and keep us posted.