240sx sr20det no spark

[cynabel]

Hello all. I have what I hope are not silly questions (know very little about these engines/cars) Helping my son to troubleshoot. He swapped his ECU for a Power FC. It ran great for a couple of weeks, then lost spark. I've read a ton about no spark situations and checked everything people recommended. All looks good except when checking pins on the ECU, several pins, including the ECU ground, have good ground, but also 8 volts?!? Might that cause no spark and/or messed up the ECU?? Also, backup power (pin 46) shows 12+ volts (not constant), but ECU power(pin 47) shows nothing?!? Could that keep the ECU from "saving" information? Thanks for your help.

[1on1]

from my understanding, the ground will complete a circuit when the CAS sends a signal to the coilpack.

First, have you tried removing the power FC (since it's standalone) and use the stock ECU; same problem?

Was the car running fine and when he went to go start the car, it didnt work? Was he tinkering with the engine?

If so, it could be a ground that ripped off the harness, bad igniter, bad cas, or check the harness carefully for any open wiring that can cause a short.

In addition, what have you done to troubleshoot the issue so more people can chime in.

[cynabel]

Thanks for the reply.. OK.. my son sold the stock ECU about a week after, so can't check that. My son doesn't seem to think he did much other than drive it and one morning it just didn't start.
I've checked the CAS and it clicks. I've read that means it's good?!? I checked the wiring to the ECU pins and, as noted, there was 8 volts going to about 6-8 grounds on the ECU plug, all coming from a yellow wire. I clipped yellow wire and wired all to good ground. The pins that were suppose to have constant power had switched power and the pins for switched power had nothing. I rewired to make that good per the diagram. The ECU is still not saving data. I checked all pins on the Ignition Control Module and I think that is OK, as well. I opened and checked the coil harness and it was fine. The coil pack harness plugs (3 pin) show good ground, 12 volts and intermittent voltage from .5 to 7 volts when cranking?!? It seems like the plugs should fire?. I smell fuel when checking for spark. I'm going to the Alexi office in Anahiem on Friday and they're gonna bench test the ECU. That may be the problem. If so, they'll ship it off. Just wanted to check everything else first, just in case the ECU is still good. Anyway, any thoughts??.

[1on1]

damn ok. Hopefully the ECU is fine.

[cynabel]

Thanks..Dropped it off in L.A... They said its toast.. They'll send it to Japan...Just gotta make sure that whatever blew it out doesn't do it again?!?

[1on1]

that's good to hear! :)