RPMs raising when stopped

hey guys i have a 1990 mazda b2200 2.2 five speed, fuel injected, extra cab. i had a question that maybe you guys could help me with on my truck... When i come to any type of stop my truck raises RPMs up to around 2000 RPMs. it somtimes goes back down to normal when im stopped long enough, but then if i step on the clutch or the break pedals it climbs back up. and then when i start to drive every thing is normal.. i have been checking my hoses for cracks or leaks and cant seem to find anything. some one mentioned to me may be its the break booster taking a dump? any help would be awesome thanks.

I was going to suggest a leaky vacuum hose. Take some carb spray and spray all the hoses while the truck is running. If the idle increases when you spray on a hose, it needs replaced.

I agree with Kovz here... Or another idea (and don't shoot me if I'm wrong) could it be a weak throttle return spring on the Throttle body. Idk what kind of spring the FI trucks used but I figure it's a pretty common problem with the carb vehicles I've dealt with.

Hope you get it figured out. I had this problem with my truck but it's carbed and I had vacuum leaks under the carb...


Hope this helps,



Fred

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