KA24DE surging idle and code 34

[RSready]

Hi guys, having a surging idle problem with a freshly rebuilt KA24DE and I'm also getting a code 34 off the ECU, which I believe is knock sensor. Here are the details:

-93 KA24DE swapped into 89 chassis
-Motor was from an automatic car, I'm using the 89 transmission and 93 automatic ECU, with a transmission harness from a 91-93 manual.
-Freshly rebuilt
-On start up, engine surges between 1800-2300 RPM
-When I clamp off the hose to the IACV, the engine stops surging and holds a steady idle at 1800RPM
-I removed the IACV and cleaned it, but it hasn't changed anything
-Carbon canister and PAIR valve have both been removed as I didn't have them with the swap. The four vacuum lines for them have been capped off near the throttle body
-I have been starting the car with a booster pack and don't have a battery installed, just running right off the booster pack. Picking up a battery today.
-Ignition timing was properly set. (At TDC, slid in the CAS so that the rotor lined up with #1 and was facing towards the front of the car)
-ECU is giving me Code 34 Detonation sensor circuit
-Car has been sitting for a year at least before the engine was swapped in, so the gas is at least a year old.

Does anyone have any idea of what might be causing these issues?

[moso]

having a bad knock sensor will cause the motor to try and adjust the timing until the knock goes away, if you set your timing with a bad knock sensor then your timing is probably wrong. check the knock sensor wiring and/or replace the knock sensor. if you cannot afford one then you can probably scavenge one off another nissan. i believe the j30 and q45 as well as the sr20de all use the same knock sensor, compare the part numbers at any parts store to find out. on a side note it has been mentioned that using the auto ecu can cause some erratic idling issues although i cannot personally attest to this but it may be worth looking into if the knock sensor dosent pan out.