Posted by Patrick M. on September 9, 2009, 12:39 am, in reply to "Over fueling what to do????"
58.179.220.165

Hi Bille. Fast idle can be caused by a number of things, I have had the problem occure on a number of occasions, I would suggest you start with checking all your vaccum hoses paying particular attention to the small hose connecting to the the idle control "air by-pass valve" at the rear of the plenum chamber. It would be a good idea with a vehicle of your age to replace all of them, then check to see if the problem still exists, this is a cheap way of eliminating a potential fast idle problem. Next I would check the idle or "air by-pass valve" coil wiring for correct continunity. Then the "temp sensor". Then the "throttle potentiometer" (throttle position sensor mounted on housing). Then the "road speed transducer" mounted on the chassic rail under the front passenger seat near the transmission. Then "the distributor module". and finally the "airflow meter" as this is the most expensive of items listed to replace. Hope this helps. Regards:- Patrick M. --Previous Message-- : ’93 Rangie, V8 auto EFI located in Perth WA. : : In the past few weeks sometimes it idles a : bit fast after the engine has reached : operating temperature about 1100rpm but not : always usually about 750 to 800rpm. : : Sometimes it will take me somewhere and it’s : fine but when I try to start it, it acts : like it has a gut full of fuel and is pretty : hard to start unless left to cool down for : 15 minutes, then it will start with the : throttle wide open but still idles fast when : the throttle is backed off, next day it : starts fine idles fine. : : Acts bit like a carburetor engine with the : choke on and only appears to happen when it : is doing the fast idle thing. : : I’m not a mechanic but I’m thinking it is : something to do with the engine temp : sensor/s not sure which ones but probably : the one that tell the ECU that the engine : has warmed up and less fuel is required. : : Can anyone confirm that I’m on the right : track and if so point me toward the : offending sensor…I notice there are several : sensors screwed into the engine at the top : just forward of centre of the engine. : : Thanks for reading and thanks in advance for : any help offered. : Edit/Delete Message :