I have an 89 D50 4X4 that I put a 3.0 V6 in. It runs great but when started, it idles up around 2k until it gets warm and then comes down and idles fine. However sometimes I will be driving along and it starts to idle high while it is at operating temp. Sometime it takes a while for it to idle properly. Any ideas? I replaced the temp sensor and had the computer rebuilt when I rebuilt the engine.