I have a 1998 Impreza ,EJ22, auto with electrical issues in the fuel pump circuit.
Under acceleration off idle, the fuel pump relay flutters causing a fuel pressure drop which in turn causes the engine to stumble.
It ONLY occurs under moderate to heavy acceleration off idle. And it stumbles really bad. I can accelerate lightly letting the rpms come up slowly and rev to the limit with smoothly with no issues. You can hear the relay fluttering as it happens.
I have done all the obvious stuff. Checked all my grounds and power. Checked for bad pins. Tried several other relays.
The signal from the ecm is good. I get the two second on when the ignition switch is turned to the on position.
I suspect that the signal that tells the ecm that the engine is running may be getting interrupted during this condition. I haven't verified this because I'm not sure what that is. Tach signal?
Anyone ever deal with this or have any ideas what I may be missing? I'm getting a little aggrevated here.