787 RFI with Erratic idle

[tnewt]

I purchase a Reman 787 engine from SBT last August and have not been able to get it running properly since. It will idle on the trailer at about 2200-2400 RPM's but once dropped in to the water it will drop to about 900 RPM's and surge up and down to about 1100 RPM's. It will take off and run as normal but the second you let off the throttle to return to idle speed it will die.
I have replaced the TPS sensor and had someone with a CanDoo Pro mess with the settings. Also, I have already replace the fuel injectors, filter, APS, Crank shaft sensor.
We have checked the rotary value and it is set properly as well.
Please help- what could the problem be!?

[Technical Support]

Re: 787 RFI with Erratic idle

If there is too much clearance between the rotary valve and cover you will have issues like what you are describing, did you replace the cover and valve?