Idle changes

[Gunshot]

I have a 86 1/2 Nissan Hardbody 6cc truck. It has 523,855 miles on it but while driving it the idle raises and lowers. It goes from 1500 RPMs to 2000 RPMs. I think it is the idle air sensor, but someone that works for Nissan said it could be the plate under the throttle body allowing air to get in? Anyone else ever have this issue?

[12Ounce]

I'm experiencing a bit of this idle oscillation on cold start-ups on a '93 ka pup. Haven't started to sleuth it out yet.

[zanegrey]

check the vacumn pressure to the fuel pressure regulator..

[zanegrey]

what is a 6cc truck??

[Gunshot]

I meant 6 clinder

[ricecricket]

I had a 85 nissan that did the same thing. All it was on mine was a little red wire came off the hot side of the battery. I thing it went to the idle sensor. I hooked it back up and it ran great.