Originally Posted by shane.,herold
My new engine has been in for awhile and runs hard but will not idle properly all the time. I have relaced injecters, O2 sensor, IAC valve rebuilt throttle body and checked for vacuum leaks 100 times. What could my problem be? a timing issue? i have a oem replacement cam chain in it which has retardation built into it. In order to compensate for this i ahve the timing advanced 18 degrees! it does not ping either. Do i need to put the timing chain in the truck that is made for the cam? and also there is a funny buzzing noise coming from top of injector housing that matches RPM level...wierd... Please help Me!!
The injector shouldn't be making buzzing sounds, though in concert with engine RPM would be something to expect if they do as the injectors cycle very rapidly and that is in concert with RPMs.
You cannot defeat the timing set up without changing the chip in the computer to go with the change in timing set. The engine won't detonate because there is a detonation sensor that pulls out the timing advance when it hears pinging. If the engine is tripping that sensor, the engine will run run crappy with poor gas mileage, low power and rough running.
Operating temp is also sensitive, the engine needs to get to and above 176 degrees to get out of cold start mode (choke). If per-chance you dropped the thermostat to less than that, it isn't getting out of start up mode which will be excessively rich for a warm engine to always be running on.