Having some electrical issues... curious if anyone ran across this before...

[2_Liter_Turbo]

I'm having a little electrical trouble, and can't seem to pin-point the problem. Curious if anyone else has ran into this, and if so, if they found a solution...

This involves my 92 240SX with an SR20DET running on AEM EMS:

I turn the ignition switch to the full "on" position to run the fuel pump (engine not running of course). And the tachometer jumps around 500 to 1000 RPM, bouncing with the fuel pump signal. Pull the fuel pump fuse, and it sits still. So far I've checked all grounds in the engine bay and the ECU, and everything is good there. I'm assuming it's a grounding issue. Tomorrow I plan to cut the fuel pump ground and ground it separately through the chassis (been meaning to do this anyways). If it's not that however, I'm out of ideas.

Any suggestions?

[RACETUNE]

PM me or Email me if you are still stuck.

[email protected]

[e1_griego]

Just to follow up (since he might not see this and reply) he posted this on our local forum:

It turns out that when I had the engine harness done back in 2005, that the people who did it had the ECU, o2 Sensor, and two other wires all powered off of one switchable 12V source. The ECCS relay wasn't actually doing anything! So I moved the ECU power back on the ECCS relay circuit, and everything works great now. Took a lot of continuity testing to find that one, ha ha.

[2_Liter_Turbo]

Thanks Alex. On vacation, so not at the PC much this week, lol.