There appears to be several posts about this problem but will add mine. While driving my motorhome last year the throttle response suddenly became very erratic.when coming off the throttle there was a delayed response resulting in sometimes having to disengage the clutch to maintain control. The idle varied from normal up to 2000 rpm. Anyway this is the culprit a 6 pin plug. Ohms reading was between 8 and 9 on each wire dropping to .5 ohms after cleaning with contact cleaner. Throttle is back to normal. I've included a photo of the fuel guage plug. If your fuel guage needle bounces up and down this needs cleaning as well.