Eddy, you're right. After doing my due diligence and price checking it was certainly on my to-do-list. That is until I cleaned up the 3 screw brown clip casing, thought to be the Idle Speed control--its located under the TB and the intake, it has a spinning disk at the end of it when you remove the exterior pig tail clip--and the black clip adjacent to the ISC on the Throttle body.
It made a difference as it stabled the idle from 1500 down to 1000 when in Park and a warm engine.
This was short-lived, however. After a few time shutting it on/off it caused the same issue, Check engine light was missing, it wouldn't turn on etc... So my next thought was to wait until the next day, but unplug the clip going to the ISC. And well, the ECU turned on every time I tried and ran steady as it did when I cleaned top and middle part of the ISC.
I think I'm dealing with the early stages of an ISC destroying the ECU. As I said, their was a pin-sized hole in the capacitor so its on my to-do list. But I'm going to see what happens and see what's the deal with this ISC.
Thanks for the help so far, guys. Keep it coming!
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EDIT: ISC id confirmed.
http://www.4x4wire.com/mitsubishi/tech/throttle_body/The sweep pattern you describe is no codes stored and ecu functioning ok.
In the words of Bill, the drunken a&p who taught me a lot of what I know, 90% of all problems are electrical. The other 50% are stupidity.
If you have a holed cap, send it off. You have an intermittent fault, probably a trace almost eaten thru on the circuit board.
Or, a quick search of car-part.com has used ecu's for your model for from 150 to 350 bucks. Rebuilt sounds better to me. One other possibility is a failing ecu relay.
