2004 Evinrude Ficht 250 TPS voltage good but no percentage change

[jwellcraft]

Hello guys, I am working on a friends motor (2004 Evinrude Ficht 250 DI) which he purchased a couple of months ago. He asked me to help him out by checking the EMM for the history report and any faults it may have. After connecting the fuel and oil and running the motor it is acting weird, it revs up high on its own every now and again and will not rev up when throttled. While looking over the connections and checking with the diagnostic software it has multiple codes for TPS circuit fault and TPS above expected range so he purchased a new TPS. Installed new one and same thing, revs high sometimes and will not throttle up and I started checking the engine harness for bad wires and once I touched the bundle of wires leading to the EMM (top starboard side) it started to rev high and if I wiggled them a bit it would go back down. I did this at least 5 times and it did the same thing so we thought maybe the engine harness was bad so he purchased an engine harness. Installed engine harness and all went on well with no problems but the motor is still doing the same thing only now if I wiggle the wires it doesn't rev up but it still doesn't rev when throttled. The TPS volts in the diagnostics reads .27 - .38 at idle and goes to 4.99 when TPS arm is moved manually to WOT but the percentage remains at 0. Once in a while when the motor has sit for about 10-15 mins and I move the TPS arm the percentage goes up to 97-100% but gradually drops right back down to 0 while still depressed. Any thoughts or suggestions you guys may have would be great and helpful. I own a 2007 Evinrude E-tec 250 now and I am really enjoying and understand that motor pretty well.

Cheers