hotwire system idleing badly

nokia_aid · Post by **nokia_aid** » Tue Dec 12, 2006 7:22 pm

hello everyone im new here,just a quick question,what would make my hotwire system idle badly,its all over the place

Post by **katanaman** » Wed Dec 13, 2006 12:28 am

if its just idle that is rough look for an air leak first. Grab a tin of wd40 and spray round all the joints you will hear the engine note change. If that doesnt show anything then give it a proper service it may or may not cure it but at least you will have ruled out things like plugs, cap, rotor arm and the like.

Robrover · Post by **Robrover** » Wed Dec 13, 2006 4:05 am

Unscrew and clean the stepper motor. Also clean the throttle butterfly and plenum air intake area. Check throttle sensor and AFM are functioning properly.

nokia_aid · Post by **nokia_aid** » Wed Dec 13, 2006 4:44 pm

il take the stepper motor off tonight,it only does it when its warm too,would that point to anything else

TimoV · Post by **TimoV** » Thu Dec 14, 2006 9:03 am

nokia_aid wrote:il take the stepper motor off tonight,it only does it when its warm too,would that point to anything else

The temp-sensor! It is probably telling to the ECU that the engine is cold, thus the mixture will get rich when engine warms up!

Use a multimeter to test it. It should say about the same resistance figures than the fuel temp-sensor, when engine is cold. I just had this problem with my 3.9EFI RR -90.

Rough estimates of the resistance values to expect:
-10C 7000-11600 ohm
+20C 2100-2900 ohm
+80C 270-390 ohm

nokia_aid · Post by **nokia_aid** » Thu Dec 14, 2006 4:28 pm

i put a brand new temp sensor in and it still does it,
tonight im cleaning the stepper motor and changing the air flow meter,i already changed the ecu,relays, fuel rail and injectors,im running out of things to try,
although i have not changed the sensor in the fuel rail yet

nokia_aid · Post by **nokia_aid** » Sat Dec 16, 2006 3:09 pm

ok iv cleaned the stepper motor and that didnt fix it,although when i unplug the stepper motor that does,although my idle is at 2000rpm and i cant seem to get it any lower when its unplugged,
it will run at 2000rpm ok but rich and then when its warm if i plug the stepper motor back in the idle goes down but then goes irratic and it tends to cut out and die,

iv cleaned stepper motor
changed ecu/afm/temp sensor/entire plenum/injectors/fuel rail/

and im about to check for air leaks
any ideas on what to try now,