My Y60 Nissan Patrol (Petrol Engine) is idling rough (fluctuates between 700-800 rpm), has slight hesitation on acceleration from standing start, backfires when accelerator is not depressed.

SOURCE: rough idle / engine surges until power is applied

Sounds like a possible vaccume hose leak?

SOURCE: engine stalls after cold start-up & release from high speed idle

I had a similar problem.  I found the filter cartridge below the pcv valve had carboned up, and after the crank case pressurized, oil was forced out the pcv supply line to the throttle body.  The idle air control valve solenoid got oil in it and caused my problem, but only when it was cold.  The pcv cartridge is accessed by removing the pcv valve and the rubber fitting that the pcv valve mounts in.  It can then be fished out with a pick set, and it is a pain because you can't see it, but you can get you hand back there.  I hope this helps you.

Jerry Koski

• 443 Answers
• Posted on Apr 12, 2009

SOURCE: rough idle, backfire on acceleration

check everything you can under the hood your air intake system all of it especially make sure all clamps are tight .. and make sure all vacuum hoses are good and not cracking or broken or just loose . you might run a little fuel cleaner through a tank of gas too cleaning the engine fuel system up some. just a few ideas.. Jerry

SOURCE: hesitation during acceleration

could be the type of plug you are using.I was told only to use ngk plugs.I recently put bosch plugs in my mazda 3 and the check engine light came on and it started missfiring.

SOURCE: 1992 pontiac grand am no acceleration, a rough idle (engine miss)

Does it have the 2.3l Quad 4 engine? If so replace the plastic piece that the coils go into, they go bad and leak spark to the cam towers and then you get a nice one or multiple cylinder misfire.