Well, after going through this thing, I am getting a re-occuring p0171 with a very intermittent stumble that sets the pending code. Here's what I have done thus far.
Found that the Injector seals were hardened and replaced them. First time I fixed this code.
Ignition service with new plugs
New Intake Tube - No Leaks
Smoke Checked the entire Vac System - No Leaks
The Stumble is so intermittent that I can barely catch it, but the rpm's drop and the pending code sets at idle. The only coincidental event that happens is that it seems to stumble at the same time that the cooling fan kicks on or off (not every time, but coincident enough to notice). My question, Theory, Guess, is that I may have a Vacume Switching Valve that is causing a leak when activating with a change in load due to the cooling fan motor running or switching states. The EGR is probably not the culprit, because it is inactive at idle.
This thing has really got me scratching my head, butt, etc ......
Any Help would be appreciated
Found that the Injector seals were hardened and replaced them. First time I fixed this code.
Ignition service with new plugs
New Intake Tube - No Leaks
Smoke Checked the entire Vac System - No Leaks
The Stumble is so intermittent that I can barely catch it, but the rpm's drop and the pending code sets at idle. The only coincidental event that happens is that it seems to stumble at the same time that the cooling fan kicks on or off (not every time, but coincident enough to notice). My question, Theory, Guess, is that I may have a Vacume Switching Valve that is causing a leak when activating with a change in load due to the cooling fan motor running or switching states. The EGR is probably not the culprit, because it is inactive at idle.
This thing has really got me scratching my head, butt, etc ......
Any Help would be appreciated
