Final tune, Need help Options

[Morph914]

Ok , so I have the engine running but it needs tuning. A little background, rebuilt stock 2.0 with D Jet, running a 123 dizzy. It fires right up and idles a little rough at first then smooths out. It revs fairly well and sounds good. The problem starts under load, it starts to stutter a bit.
I have not messed with the adjustment screw on the ECU or tried adjusting the throttle position sensor, or been able to check my fuel pressure.
I’m hoping to rally any troops in the north Florida area to help me get these final details ironed out.

Thanks in advance,
John

[JamesM]

SET RUNNING FUEL PRESSURE BEFORE ANYTHING ELSE.

The ECU knob only impacts mixture at idle (assuming your TPS is good) The way I normally set that is to get the car fully warmed up, let it idle, start with it on the rich side and then lean it out (turn knob counter clockwise) until the engine starts to hunt and then turn it back clockwise 2-3 clicks. You may want to rev it a couple times in between adjustments of the knob to see where it settles.

Rough idle when cold? is your AAR kicking up the idle speed when cold as it should? guessing it either isnt or your idle mixture isnt ideal.

Stuttering under load? That one is a little tougher to guess at without more information or seeing what the car is doing. Could be a lot of things but if your fuel pressure is adjusted properly and you dont have any restrictions in fuel flow then you may be looking at a bad/futzed with MPS, or possibly bad TPS. Other than fuel pressure there is no adjustment that is supposed to be occurring on d-jet that would affect mixture under load.



Good Luck! Looks like you have a really clean setup there.