idle drifts

[FJ60BigLou]

Once again I am turning to the experts here on MUD. I have an 85 FJ60 that I am trying to fix all the issues so I can get to the restoration. May end up restoring just by fixing all the issues!! Doubt it though, I have big plans.

Latest issue: About a month ago I noticed the idle was drifting up. Since this is a parttime DD (not as much these days), I have been starting and letting it run for about 10-15 minutes every few days during the cold weather just to keep the battery charged and not let the engine forget what it feels like to be warm. When I first start my good friend, the idle sits comfortably around 650. After a few minutes at 650 the idle starts to slowly drift up until it hits about 1000 (takes about 7-8 minutes to hit 1000) and then it sits there until I turn it off another 8 or so minutes later. I have driven once or twice the last few weeks and at stop lights I have noticed the idle higher than normal around 1000-1200 RPMs. Thinking it had something to do with the choke, I stopped using it when starting and pumped the gas pedal about 5 times before turning it over.

Any thoughts as to what is going on and how to get him back to that comfortable, low growl at 650? Could this be a cold weather kinda thing?

 

[klinetime574]

Check ignition timing, and check to make sure the accelerator linkage is not binding anywhere. After that I would make sure the choke plate is operating correctly.

Although the Hot Air Intake and the heat riser flap could be responsible for this. After 7-8 minutes is it at operating temperature? I would make sure that it is idling high only after it is fully warmed up.