13B Series 4 6-port. Microtech Digi series 1 pro (which i dont think has voltage compensation).

Basically what is happening is in normal daylight hours, I'm driving along and only running the stereo. Car drives best like this.

If I put say the fan on it takes the engine a little longer to respond. If I put the headlights on its noticably worse.

I have gotten used to putting my foot down, and waiting a few seconds for the revs to come up before bringing the clutch out, depending on how many electrics im running.

Now i'll explain it as I sit in my drive in neutral.

1) Lights off, all electrics off except the stereo, hold the revs at 1500. They sit there steady.

2) Lights on, fan on, hold revs at 1500. They sit there for a second, drop to about 1000, little backfire, jump back up to 1500, drop again.. drop jmp drop jump.. over and over.

could this perhaps be a fuel pressure thing?

All my grounds are good. I was thinking maybe the positive wires to the fuel pump? Just wondering if anyone else can see anything else that could be causing this?

thanks !

 

Is your standalone controlling your ignition? I'm guessing that voltage drop at the ECU is causing it to shut down momentarily, that would cause your ignition to drop out... and could cause the afterburn.

Is your alternator charging well? Check if there is a voltage drop at the ECU... I know that Haltechs have issues with low voltage, perhaps Microtech does too.

 

The ignition is stock. I still have the stock ECU heh, just the MT runs the fuel. Watching the ECU, it doesnt appear to reset or turn off, but I will measure the drop and see how much juice its getting.

The alternator is charging fine, with a brand new 70 amp cable running from the alt to the battery.

Might be time to rewire

 

Sounds like either your alternator is not producing enough juice, your battery is weak, or you have a short somewhere in your system. I would have thrown in inadequate grounding too, but you said that you have that covered (are you really sure?)....