Rover 400 (S reg) 1.6 Throttle sticking - Chris Jones
I was caught in traffic the other night and found that my throttle would rise as i depressed the accellerator but would not return to normal. Releasing the clutch allowed the engine to take the revs down. I pulled over and found that under the bonnet was extremely hot. The fan was not running but the car temp gauge was never above its normal setting (I have since heard the fan cut in). Has anyone any ideas? ever experienced the same symptoms? I have now lost confidence in the car. I went to my local rover garage who said they would chareg me £56 just to connect the diagnostic box to the cars engine management. I think this is complete robbery (they also said they would need the car for the day to perform this test, I assume to try and justify the price). Would appreciate any advice. Does anyone think I have a serious issue? Symptom has not reoccurred.

Thanks all...
Rover 400 (S reg) 1.6 Throttle sticking - edisdead {P}
My old man has similar symptoms on his T-plate 416, which just had it's 60k service. Rover told him it's a problem affecting lots of 400's, apparently the throttle body has a design defect causing it to stick. They quoted him £140 to replace the defective part. My own '95 N 416 is unaffected.
Good luck,
Ed.
Rover 400 (S reg) 1.6 Throttle sticking - David Lacey
Yep.....plastic throttle body, for sure.
Rover 400 (S reg) 1.6 Throttle sticking - Stuart Lawrence
Replace it with the 52mm alloy one. You will also see an improvement in throttle response with this.