S13 Redtop sr20det no spark/spark when hand turning CAS

[killvhs]

Good Evening/Morning all,

This is my first forum post so excuse me if I’m ignorant in regards to forum procedures.

To begin I purchased this car non running and after discovering a no spark issue I managed to get it running after re-installing the crank angle sensor. I had it idling/revving for about a minute before i realized the water pump was pissing coolant and then after a good rev the boost piping blew off. I replaced the water pump and fixed the piping and after starting it up again I noticed a severe hesitation issue upon sudden actuation of the throttle from idle (no hesitation if throttle is applied as the rpm’s dropped) and the temp gauge had stopped working. Spent several months chasing red herrings, before recently, no more spark again. I tried again to re install the CAS to no avail, however when i plugged a separate one in and turned it by hand I would receive spark. At this point I’m lost and am looking for some help. It seems preposterous that it could be relevant but I’ll add that i removed the connector to the IACV and after plugging it back in again the no spark issue returned. Car has power FC ecu. My best guess right now is there’s some sort of voltage draw somewhere while cranking that is barring the CAS from receiving enough power to signal to the ecu to fire? I’m not the best with electrical diagnosis so any help would be appreciated.

[Hijacker]

https://www.nicoclub.com/service-manual ... +v1.11.pdf

If you haven't already grabbed a service manual, do so. You have a redtop and this manual is for an S14 blacktop, but the steps for solving a CAS related no spark would be the same albeit the ECU pins will be different.

I see you have your car listed as a Silvia in your profile. Is it a Silvia or is it a 240SX? That kind of matters. If it's a 240SX with an SR swap, are you running a custom wiring harness or something more like a Wiring Specialties conversion harness? That kind of information is necessary to track down things like where power is sourced for specific equipment. The CAS is powered via the ECCS relay while the IACV is powered from the Fuel Pump relay on a 240SX. The Silvia powers the IACV directly off a fuse and is independent of the fuel pump circuit.

Best thing I can say for now is that if you're having electrical problems is to go through the wiring harness and look for damage. Something could be shorting or grounding and is causing your erratic issues.