3FE Still Has Rough/Fast Idle??

Apr 30, 2003
:beer:Has anyone ever solved there 3FE rough/fast idle yet. I had my intake system decarboned and my fuel system cleaned. New plugs, wires, cap & rotor.
Checked for vacume leaks with starting fluid (Found None) Replaced the vacume modulator.
Mine runs much better but when i start it in the morning the idle goes right to 1500rpm then about 10 seconds later it will drop to 1100 to 1050rpm. It will stay there for 4 or 5 miles then in gear it will drop to around 950,
after it has warmed up fully it will be around 700rpm. My questions are, is this normal at start up, and will it hurt my drive line shifting at a high idle.
     Thank for the help
Mar 28, 2003
After trying all that, have you checked out the idle speed control valve. I think a new one is @$300+/-. I haven't worked on mine yet, but I understand you can clean it and check it per the procedure in the FSM. Saw that on the 3FE board. It supposedly will help that or at least eliminate that as a contributor.
Mar 31, 2003
Phoenix Oregon
you are definitely out of normal range for a 3fe on this one. at start uop when cold mine hits about 1100, after worming up will sit at about 600. I think seminole is on the right track with sthe sensor as it seems you have already adressed everything else. well maybe this is a dumb one but how much tension do you have on the throttle cable from the cruise unit? probably already been adressed but after resetting the valve clearances I over adjsuted mine and had the same problem. just a thought.....
Dave :beer:

Users who are viewing this thread

Top Bottom