Skip to main content
Topic: idle speed 8.3 higher after warming up? (Read 779 times) previous topic - next topic

idle speed 8.3 higher after warming up?

Hello,
I'm not sure where to go with this, so here goes.  Engine starts, runs fine, idles about 600 rpm when cold, warms up just fine.  I went to Dallas over weekend, stopped in Houston (on way there) and idle speed now at about 1200.  Put in N as I was stopped and the engine was pulling making braking difficult.  Well...., dang thing finally got back into gear after several tries (because idle speed was too high).  Not good whilst sitting at stop sign!  Once we got back in gear, drove to Dallas with no issues (didn't stop to check).  Once there, parked the bus and recurrence of issue (unable to shift from N to D) as idle too high.  Tried the cruise control pushing on the resume/set buttons and these were unresponsive.  Let the engine cool down about 15 mins, idle speed lower and no problems shifting.  The long and short of it, I have the King Control fly by wire accelerator, I have checked and carpet is not hindering nor affecting movement, freely movable accelerator pedal.  There is something that is causing this and it is somewhat of a safety issue and I would like it addressed.  I was thinking someone else must have had an issue with this?  Best of travels!
Best of Travels

Re: idle speed 8.3 higher after warming up?

Reply #1
Check the 2 return springs where the king control wire attaches at the engine,they are prone to breaking,can buy them at Lowes.
Search forum,plenty of posts about the springs.
PS,fill out that profile so we know exactly what you have.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: idle speed 8.3 higher after warming up?

Reply #2
Thanks!  Will check today.  I went on Beamalarm site and found the post.  Thanks!
Best of Travels

Re: idle speed 8.3 higher after warming up?

Reply #3
Don't forget that King Control has a way to force high idle.  Are you inadvertently setting it higher?  King control web site has good diagnostic info.  Also the owner is available for questions.
There are about 5 plug connections near the King control box in  the corner of the engine area.  Unplug and replug?  Clean with contact cleaner?

Re: idle speed 8.3 higher after warming up?

Reply #4
John and Barry,
Thanks! Went to lowe's got the springs that are mentioned in Beam alarm.  I went home, and yes one was broken.  I replaced both with the new springs from Lowe's after cutting and bending to match the old ones.  I haven't driven but expect this to be the solution as one of the springs was broken and separated from the mounting.  WhooHoo, Gotta love this FF group! 
Best of Travels

Re: idle speed 8.3 higher after warming up?

Reply #5
Quote
runs fine, idles about 600 rpm when cold,

On my 97 8.3 the proper idle speed is 750.
jor
93 225
95 300
97 270
99 320

Re: idle speed 8.3 higher after warming up?

Reply #6
Well, I will adjust mine a little higher.  I think it is around 700 after warming up some.  It does "rumble" a little when starting cold.  It does smooth out after warming up.  Thanks for pointing that out.  Best of travels.
Best of Travels

Re: idle speed 8.3 higher after warming up?

Reply #7
FWIW,
The new springs did the job.  I drove it this weekend for about 500 miles and did exactly as it was supposed to do.  Idle was fine.  Thanks to all. 
Best of Travels