Hi all,
I have been chasing this problem in my 86 GN for a few weeks now and I cannot figure it out. The problem is that it has a random stumble all through out the RPM range, like one cylinder is not firing/combusting correctly but its not consistent. Also when I first start it up it idles smooth as glass and when it warms up a bit after about 45 seconds to a minuet the stumble/shake comes and stays. It is a brand new engine that I have put about 25 miles on. I have set the cam sensor twice. I have also reset the IAC and adj. the TPS at least a dozen times. When it first goes into closed loop the IAC is about 25, but it randomly drops to 0 somtimes and stays there at idle. The current TPS reading is .044. I had a mechanic buddy of mine graph the injectors on his scan tool and he said they looked fine although the #1 injector is alot louder than the rest. I also put new AC Delco plugs in and new plug wires. The MAF sensor passes the tapping test and airflow is with in spec. I put a new fuel filter in, new O2 sensor, and a bunch of things I cant remember right now. Im tempted to replace my coilpack but I dont want to keep throwing money at the problem. Sorry for the long post. Any help would be appreciated. TIA
I have been chasing this problem in my 86 GN for a few weeks now and I cannot figure it out. The problem is that it has a random stumble all through out the RPM range, like one cylinder is not firing/combusting correctly but its not consistent. Also when I first start it up it idles smooth as glass and when it warms up a bit after about 45 seconds to a minuet the stumble/shake comes and stays. It is a brand new engine that I have put about 25 miles on. I have set the cam sensor twice. I have also reset the IAC and adj. the TPS at least a dozen times. When it first goes into closed loop the IAC is about 25, but it randomly drops to 0 somtimes and stays there at idle. The current TPS reading is .044. I had a mechanic buddy of mine graph the injectors on his scan tool and he said they looked fine although the #1 injector is alot louder than the rest. I also put new AC Delco plugs in and new plug wires. The MAF sensor passes the tapping test and airflow is with in spec. I put a new fuel filter in, new O2 sensor, and a bunch of things I cant remember right now. Im tempted to replace my coilpack but I dont want to keep throwing money at the problem. Sorry for the long post. Any help would be appreciated. TIA