(VP44 style pump, with manual transmission) 

Vehicle Symptoms
Cruising in 3^rd or 4^th gear a surge will occur with no D.T.C. (Diagnostic Trouble Code)
It can occur in all gears but problem is mostly seen in 3^rd and 4^th gear.

Vehicle:
Nissan Patrol 3.0L with ZD30 direct injection engine
Nissan Navara 3.0L with ZD30 direct injection engine

Date code:

2000-2006 (with VP44 style pump)

Description

The vehicle will surge or intermittently go into limp home mode when driving in either 3^rd or 4^th gear. The neutral position sensor briefly loses the position of the gear and the ECU (thinking the vehicle is in neutral) reduces fuel quantity. With the ECU constantly changing fuelling as it responds to the vehicle being in gear then in neutral then back into gear it results in a surge condition.

To simulate this problem, take the vehicle on a test drive. When the vehicle begins to surge move the gear stick laterally and hold it in place. If the surge goes away while holding the gear stick in position and begins surging again after you release the gear stick it indicates that the neutral position sensor is faulty.

Solution:

Replace Neutral Position switch on vehicle