96 240SX with redtop S13 SR20DET, problems with starting, key cylinder related.

[fortwayne240]

Hello. I have tried posting on here before, but I get the obvious stuff like "search" and "replace your ignitor". I actually need some real help here, as the search feature leaves a lot to be desired. If the forum had the information I needed, I would not be posting.

I have a 1996 nissan 240sx s14 with the s13 redtop motor in it. The car has been running great for almost 2 years now. All of the sudden I can't get the car to start. NO SPARK. Car was driving, then I came to a stop and the car sputtered and died. That was 2 months ago. I have replaced everything that I can think of..... CAS, Ignitor chip, ECU, completley checked wiring harness and all connectors for continuity. I have tested the coils, TPS, MAF and the IAAC Valve system. I know that some of these items dont even relate to the issue, but i figured what the hell.

Now I believe I have made some progress. I found the car does have spark, at the EXACT moment that the key is switched off. I was having a friend crank the car over while I held a screwdriver in one of the coil packs near the block, in order to visually confirm the spark. As soon as the key was shut off I felt a horrible jerk of electricity. and yes, I did it again just to make sure that I was not dreaming. WOW does that hurt.

So I went inside the car to the key cylinder. I found that if I cross the two terminals on the back of the key cylinder rapidly while cranking the car over, I get some hella loud bangs from the exhaust pipe. This obviously tells me that when I cross the terminals on the key cylinder (ignition and 12V constant) that I am causing something to producing spark. I can only assume that some aspect of the ignition system, relating to the interior wiring under the dash or inside the key cylinder is to blame, can anyone confirm or deny this thought?

Can anyone tell me what the hell is going on?

[rogoman]

Looks like maybe you hit the nail on the head. The ignition switch itself may be bad.