Dlipp_
Newbie
Still trying to get some insight on this, when I feel like I’ve narrowed it down, I’m just back to square one. Sorry for the long post.
Did a lt4 hot cam, not sure if that will cause the misfire, tuned ecm from black bear for it.
97 5.7l , random misfire, shakes every few seconds or so at idle. First start of the day it fires right up, will crank and crank and crank unless I crack the throttle just a little bit any start after that. Even 3 seconds of running on the first start of the day.
Through the forums, speed shops, my own diagnosis I’ve replaced within the past couple weeks
Accel Distributor
Ignition control module
Coil
Plugs
Wires
3 different Ac Delco Caps
Fuel filter
Delphi Fuel pump
Standard motor parts upgraded Spider injection
MAP sensor
MAF sensor
Both upstream o2 sensors
EGR is deleted with the tune
New Crank sensor
Coolant temp sensor and the pigtail
With the cam I did the ls6 springs, retainers, keepers, new lifters, new pushrods, cloyes timing set
Now this is where I’m stuck at, when i unplug the MAP sensor truck fires right up no problem. I sprayed everything I could up top with brakleen for vacuum leaks, no difference in idle.
It’s showing misfires on every cylinder except 8. 2 the most, plug looks fine.
Did a lt4 hot cam, not sure if that will cause the misfire, tuned ecm from black bear for it.
97 5.7l , random misfire, shakes every few seconds or so at idle. First start of the day it fires right up, will crank and crank and crank unless I crack the throttle just a little bit any start after that. Even 3 seconds of running on the first start of the day.
Through the forums, speed shops, my own diagnosis I’ve replaced within the past couple weeks
Accel Distributor
Ignition control module
Coil
Plugs
Wires
3 different Ac Delco Caps
Fuel filter
Delphi Fuel pump
Standard motor parts upgraded Spider injection
MAP sensor
MAF sensor
Both upstream o2 sensors
EGR is deleted with the tune
New Crank sensor
Coolant temp sensor and the pigtail
With the cam I did the ls6 springs, retainers, keepers, new lifters, new pushrods, cloyes timing set
Now this is where I’m stuck at, when i unplug the MAP sensor truck fires right up no problem. I sprayed everything I could up top with brakleen for vacuum leaks, no difference in idle.
It’s showing misfires on every cylinder except 8. 2 the most, plug looks fine.