high idle and check engine light

[muscleinc1320]

just rebuilt my KA to all stock. The motor runs and starts great but it automatically idles at 2k rpm and climbs to 2500 and stays there after awhile of running. the idle is smooth the whole time also. the check engine light comes on when going up to 2500 and stays on. I believe i have the timing set correctly at 20 when i set it i wasnt sure if the TPS needed to be connected or disconnected. i want to check the engine codes but forgot how to put the ecu into mode 3 so i can read the codes. any help is appreciated. thanks.

[Rev_D21]

Just turn the knob on the side of your ECM to get Mode III. Report back with codes. Do you have a vacuum leak somewhere?

[muscleinc1320]

how will i know its in the right mode. i know last time i have difficultly knowing which mode was which. also i thought there might be a leak but i have yet to find any. im still going through looking for any broken or old lines i might or should replace. just in case.

[blueballa]

check your egr as well.