300E idles at 500rpm!! IS IT NORMAL???
 

Hello Board,
My 300E has been doing this for a while. The idle speed is at a dismal 500RPM!!!!. I at first thought that it was normal, my car sounds quiet,but it feels very underpowered during acceleration. I have cleaned out the idle control valve. What could be causing this??


I have replaced:
Cap and rotor
Plugs and wires
Air filter
Cleaned idle control valve
All vacuum lines
Fuel filter
Injector seals


What could it be??

ECU??
O2 sensor??
Fuel injectors??

HELP!!!

500 is low but if it idles smoothly and will not stall
it has to be ok.

mine idles at 650-700 range. if you haven't done so,
clean throttle linkages, pour injector cleaner - techron,
and drive long and hard.

Well this is an "open" question, but what could be the cause of my car's dismal 500rpm idle.
My previous 1989 300E idled at a steady 800rpm, but it also had issues.It's gone now.
What could cause my 1987 to have this low idle??

Would a worn potentiometer cause this??

my 86 now idles at 600, after putting a new o2 sensor, before it was 700, same as you new plugs wires ete. ran bad at first so I disconnected the battery for a little bit it smoothed out I will know more next tank of gas

Just a suggestion - run a search using 'CIS' (the fuel injection system you have, I think), 'low idle' and 'underpowered' and see if it flags anything. The search function is quite good on this site.

If I remember correctly, 650 or so out of gear, 500 in gear is the correct speed.

Peter

i believe the fluctation should only be 500rpm max!!