Bret
Newbie
I've been chasing this problem for a while with little results, the truck is also throwing absolutely no codes. The Suburban started out with a variable rough-ish idle where it would idle up and down about 100 rpms. It idles generally in the sweet spot of about 650 rpms.
So far I've replaced:
IAC, Fuel Pump, Fuel Filter, Fuel Pressure Regulator, Lower and Upper intake manifold, and all Lifters and Pushrods, new distributor, new plugs and wires, and all 8 injectors. I've also removed the EGR to ensure its not stuck, and the piston still moves freely and doesn't seem to get stuck.
After finishing with the injectors and IAC, I started it and it idled absolutely perfectly for about a minute or two, and then it went rough and started stalling. After stalling, it would take a couple seconds of cranking and some gas pedal action to restart the truck. I remembered that some IAC need to be calibrated, so I took the truck for a drive and it stopped the stalling issue, but it still has a rough idle and in some cases while giving it heavier throttle, it will feel like it has an occasional miss.
When looking at everything through torquePro, the engine does show a "Current Misfire" value of around 2-6 for I think cylinder 6, I'm not sure if that is a high enough amount to warrant any concern.
The truck doesn't feel like its running rough while moving, aside from that occasional miss. Any help is appreciated.
So far I've replaced:
IAC, Fuel Pump, Fuel Filter, Fuel Pressure Regulator, Lower and Upper intake manifold, and all Lifters and Pushrods, new distributor, new plugs and wires, and all 8 injectors. I've also removed the EGR to ensure its not stuck, and the piston still moves freely and doesn't seem to get stuck.
After finishing with the injectors and IAC, I started it and it idled absolutely perfectly for about a minute or two, and then it went rough and started stalling. After stalling, it would take a couple seconds of cranking and some gas pedal action to restart the truck. I remembered that some IAC need to be calibrated, so I took the truck for a drive and it stopped the stalling issue, but it still has a rough idle and in some cases while giving it heavier throttle, it will feel like it has an occasional miss.
When looking at everything through torquePro, the engine does show a "Current Misfire" value of around 2-6 for I think cylinder 6, I'm not sure if that is a high enough amount to warrant any concern.
The truck doesn't feel like its running rough while moving, aside from that occasional miss. Any help is appreciated.
