Hello to all,
I have had an ongoing problem with my idle for some time now and am posting now because I am now clueless as to what is causing this condition.
When cold or cool and before the engine has had time to run,the idle is normal in every respect, I have it set to approx. 675 rpm's. after a 10 to 15 min run and it is at operating temp., or after a short to medium highway run the idle will climb and hover about 200rpm or a little higher. this condition happens very intermittenaly and as fast as the idle jumped to its higher position, it will fall back fast to normal. I have observed the linkages and accelerator pedal and they are free and do not stick, and when this condition happens, the linkages do not move.
My last crack at it today was to re-tighten all fuel line conections before the ip since I thought it might be air, but it still happens.
Believe me all pm's and all other items have been checked, the only thing left is this a problem with the ip internally, does something change inside the ip when the engine temp rises. I had the ip rebuilt 6 yrs ago and all was fine.
Has any one else experienced this phenomenom with there 617 engines, please post if you have any ideas.

Thanks
Peter
1984 300d 270k.