Questions and Answers
Hard Body Runs Rough
Q. I have a 1997 Nissan Hardbody automatic with 65,000 miles on it. I have had cap, wires, plugs, rotor, distributor, EGR valve, Oxygen sensor, and air filter replaced had a compression check and injectors cleaned and checked. I have taken it to two shops and they both don't find anything wrong, and of course it doesn't miss when they drive it.
I have had it hooked to computer diagnostic with no codes showing. When idling the truck runs fine and then there is a slight popping psst noise and it goes rough for a second and then it is fine. It happens randomly at lights and stop signs and when rolling at slow speeds like into a parking spot it starts to buck. It idles at 1000-900 rpms in Park and Neutral but when it is put into Drive it drops down to 5-600 rpms. It only seems to happen when the engine is warm.
The truck runs great on the road and has good power it is only when idling in Drive it gets rough. I noticed that there is a smell of sulfur randomly after the engine runs for a while, I had the cat checked and it was fine. I have read what you said about the IACV valve may be bad and also the PCV valve needs to be done.
What other components are in the air intake system that should be checked and replaced? I would like to be well informed when I take to the dealer to ask the right questions and not replace things that are fine and vice versa? When my EGR was replaced it was full of carbon gunk. I would like to replace them all because If the problem persists I want to sell the truck and start over.
Thanks for all your help this site is very informative.
WayneA. This is a little tough to try and diagnose without seeing the truck, but I feel the problem may be with the Idle Air Control Valve (IACV). They build up with gum and varnish and cause an erractic idle like you describe.
The sulpher, or "rotten egg" smell is normal under certain conditions such as quick accelerations or hard driving. I really don't think it's related to your idle problem.
Additional Information provided courtesy of ALLDATA
