First off let me contextualize what I mean by pig rich.
Full tank of gas extinguished in 63 miles. So ~ 2.7 mpg.
That kind of rich.
I have tested and replaced most of the usual suspects: TPS, coolant temp sensor, AFM, fuel injectors, FPR and damper, fuel filter, fuel pump, ignition components, idle air control, cold start injector....
No I will describe the symptoms:
Difficult long crank cold starts. Three crank warm starts. High idle with a coughing erratic black smoke put put put rhythm. Black smoke under load, though the nvh subsides and the truck almost feels normal. Surges when coasting.
One observation: these symptoms began months ago. Truck was running and driving okay with exception of high idle with a hint of vibration. Then while driving on the interstate there was a large thud/bang and the CEL illuminated. Pulled over and the truck was running rich. Shut it down and pulled the EFI fuse for ten minutes. Re-started and it was fine. Over time though this condition became more and more frequent. Now it just is.
Another detail: the CEL does not illuminate when I turn the key to ON. Does illuminate during the cranking process and remains on while the engine is running. Cannot under and circumstance get the diagnostic port to provide codes. Jumpers do nothing.
I have visually checked all grounds and the ECM itself. All looks right and tight. Yes I will do voltage checks in the coming days.
My question: What controls the injector timing and pulse widths? Basically the ECM is telling the fuel system to provide max fueling at all times.
I am thinking this is a wiring issue or the ECM itself. Feedback welcome before I drop $500+ on used components.
Full tank of gas extinguished in 63 miles. So ~ 2.7 mpg.
That kind of rich.
I have tested and replaced most of the usual suspects: TPS, coolant temp sensor, AFM, fuel injectors, FPR and damper, fuel filter, fuel pump, ignition components, idle air control, cold start injector....
No I will describe the symptoms:
Difficult long crank cold starts. Three crank warm starts. High idle with a coughing erratic black smoke put put put rhythm. Black smoke under load, though the nvh subsides and the truck almost feels normal. Surges when coasting.
One observation: these symptoms began months ago. Truck was running and driving okay with exception of high idle with a hint of vibration. Then while driving on the interstate there was a large thud/bang and the CEL illuminated. Pulled over and the truck was running rich. Shut it down and pulled the EFI fuse for ten minutes. Re-started and it was fine. Over time though this condition became more and more frequent. Now it just is.
Another detail: the CEL does not illuminate when I turn the key to ON. Does illuminate during the cranking process and remains on while the engine is running. Cannot under and circumstance get the diagnostic port to provide codes. Jumpers do nothing.
I have visually checked all grounds and the ECM itself. All looks right and tight. Yes I will do voltage checks in the coming days.
My question: What controls the injector timing and pulse widths? Basically the ECM is telling the fuel system to provide max fueling at all times.
I am thinking this is a wiring issue or the ECM itself. Feedback welcome before I drop $500+ on used components.
