Boost leak test done no leaks that I can hear . Idle control switch and pigtail checks out good. I changed the throttle shaft seals and did a fiav block off today. Car is worst than before It will start but won,t maintain the idle as it now cycles up and down constantly. I need your help.
The car will not idle with the biss terminal grounded and the logger plugged in so I can't reset the biss. If I disconnect the ground and leave the logger connected the car idles. Note for some reason the coolant temp reading on the logger showed 158 degrees. (I am assuming celcius) while the gauge on the dash was in the midpoint. The car has a new radiator, temp sender and rad fan sensor . Before all of this the car sat for 5 months for a boat load of maintainence.
Edited by dmj (04/17/12 04:09 PM)
Posts: 673 | From: orlando FL | Member Since: 02/02/08 | IP: (126.96.36.199) |
Replaced the coolant temp sensor with oem unit and tested it before installation. Tested the voltage at the connector both within specs. But the car still stalls on deceleration. At this point I am going to remove the ECU and take a look at the board for any damage.
What other maintenance did you do with the car? Was it doing it before?
Check timing, TPS, check ecu(like mentioned), Idle switch and ground on the t-body. I was having the same problem for the past year and could not figure it out. Then I remembered that the needle in my speedometer was bouncing up and down. Messed around with the cable and speedo housing for a bit and finally solved my problem.
Avoiding danger is not cowardice. Courage without discretion is no good. Or you can just say Bahala!!!
Quote: The car will not idle with the biss terminal grounded and the logger plugged in so I can't reset the biss.
If it won't idle with the biss terminal grounded, the biss screw may be closed too far. Open the biss screw most of the way, then ground the terminal. You will start with an idle that is too high and close the biss screw to work your way down.
Posts: 107 | From: Vacaville, CA | Member Since: 03/01/11 | IP: (188.8.131.52) |
Yes, that hints that there is no more adjustment in the idle motor if the car can't idle on it's own. Remember that all the idle stepper motor is, is a pendulum essentially. When you ground the pin, the ecu sets the stepper motor in the middle of its throw. Then you set the biss screw to be at the ECU's target idle.
Ok .so I tried the suggestion above backed out the Biss, grounded out the terminals and the idle is all over the place between 600- 1800 rpms. I slowly tried to turn in the biss screw to set the idle and it did not help so I disconnected the ground and It idles on it's own at 850-950 rpms,but every few minutes it starts cycling up and down again.I drove the car about 55 miles today and fortunately it did not stall, the idle drops under 500 rpms when coming to a stop but recovers quickly and cycles up and down at least three times before settling to about 850 rpms.