Originally Posted by
gcfcos
Hey guys little help needed. My saph cos 4x4 has a poor idle, when cold on "choke" it idles fine but soon as it starts warming up the idle will drop down suddenly and rev itself up to keep itself running and then idle for 5 seconds ok on its own and then the idle will drop down almost to the engine cutting out and it revs itself up in order to keep itself running. It has a stage 3 msd chip but with my old stage 1 pts chip it will run and idle fine?? I was told by msd to disconnect the idle control valve and set the base idle and then to plug it back in and it will re set itself but it's still doing the same thing. Anyone else experienced this? I've Taken the iscv out and stripped it and cleaned it
There are many causes of issues like this which are mainly covered in a set up like air leaks, fuel pressure, sensor alignment, co trim, ecu voltages, throttle pot calibration, so many things can make a big difference, but if your 100% sure the car is set up well,maybe it needs a little touch of fuel adding into the map to stabilise it ? What is the AFR/CO level? Is it closed loop controlled? If so maybe the closed loop correction strategy needs a little bit of work to suit your engine.