headlight on, idle revs goes down? updated 16/11/2009!

[altong0840]

hi~i got a D15B4 twin carb EG, recently 2 problems on the car, seach nothing on the forum, so open this topic


problem1 : Fast idle not work, the idle up to 1400rpm after warm up in P gear
but drop to 900rpm in D gear, is it normal>???

problem2: idle 900rpm without headlight on is smooth~ but feel stall and drop to 700rpm after turn the headlight on/the fans/any electric stuffs...


it is twin carby engine but running a ecu to control the fuel/air mixture, but no iacv on it~ so is there anyway i can anything to fix the problem??cheez




[SIZE="6"]I just check the voltage by the mech shop and it shows that


P gear(0 rpm), no elec load, battery 12.5V
P gear(1400rpm), only start the car, no other elec load, battery 14.0V
P gear(1200-1300rpm) , start the car and and headlight, no other elec load, battery 13.8V


so the professional told it is not about the alternator, is about the carby setuP~


thanks everyone!

UPDATE :16/11/2009


thanks for everyone in here first, recently i had been replace my ground wires, the one relate to the headlight, low the idle to 1200-1250rpm when P gear

before replace the ground wire: 1300 RPM (P gear) drop about 300rpm when headlight on

after replace the ground wire: 1200rpm (P gear) drop about 100-200 rpm when headlight on, 950 RPM in D gear when healight off, 700-800 RPM in D gear when headlight on

so it seems like getting fix~ but the auto choke still need to be check~

will update ASAP i found the problem