I just got an 1988 Toyota pickup 4x4 22re efi, while just sitting there the truck idles good with no problem, i drove it around the block for the first time today and after it warmed up when i would let it idle i noticed the idle would drop down then come back, drop down and come back up untill i would press the gas again then it would stop. any ideas why?

 

vacuume leak probably...start searching for cracked rubber lines.

 

Its probably the cold air idle valve. Id start with adjusting the idle control valve to lower your elms a bit and if that doesn't help clean out your throttle body and replace the cold air idle valve.

 

Got it fixed

Thanks for the info it was a valve leak i found it right on the fuel injection manifold.
Dwayne