Odd idle at start up.........93/Sc400....

[rafiqi]

...my car has (SC400/93)..started to have runaway idle at start up.
I.e it will rev up and down to about 1500 rpm and then back down to about 700 for about 1-3 mins and then just settle down.I changed the idle valve and checked for vacuuum leak...all to no avail.
Any ideas?
Thanks.

 

[Big]

check ya thermostat,temp- as my truck was doing similar things you have mentioned and when I took the thermostat out and the crap that was stuck in it,it settled down real nice and ran good..ecu I think was compensating for the lack of temp and idle,feul,etc was playing up big time..:shrug: