falling angel

Here's the backstory...

Getting this car running again (91 240 with redtop, 62 ecu) was my spring project. Replaced tps, coolant sensor, plugs. I also had to rewire the ecu harness as there were some issues. A short with the red power cable near battery tray and the rpm feed wire was hanging on by a thread. Also wired in my consult cable, it works fine.

Here's the problem...

Car starts up wonderfully now. It will idle at about 1600rpm when cold then drop to 1200 ish. No misfires or anything, timing around 26-28deg. After I start driving, We'll say quarter mile or so, the car will then idle at 850ish, timing at 15deg.

The car also has a small bit of a hesitation/surging part throttle when cruising. Still pulls hard, no misfire, but still a little bit of fluctuation felt when on throttle.


I can add that there is a walbro installed in the tank already, stock fpr. I have the o2 sensor (86 as opposed to 87 300zx turbo has correct connector ;-)) but have to find a way to get the original sensor off. I'm thinking that the o2 in conjunction with the fuel pump may be causing the issues at least with the hesitation, can't really say for the idle though.