I recently purchased a 1990 Toyota Pickup 22re 4x4 from Montana and the guy we bought it from said it idles high when you first start and when it gets warms it stops idling high. It also takes a little bit to start before it gets warm. We drove it 1100 miles from Montana to Nebraska and It drove great! But recently it started to surge when I'm in neutral and my foot is on the brake. If i take my foot off the brake then it stops surging. Does anyone no what causes this and how to fix it? I'm thinking the brake booster?

 

Here is a link to test your break booster

https://www.yotatech.com/forums/f116...ooster-131024/

 

When it starts surging do you have any heat coming out of the heater?