Does the idle adjuster screw raise the idle any? If not remove screw and clean the passage. Can't hurt

 

yes, it does, but the problem is that the truck runs good 'sometimes' in which case it idles around 900rpm, and when it runs badly it drops..
i suppose bumping the idle up would be a bandaid to keep it from stalling, but when it runs good it will be too high

 

You are describing an idk circut malfunction kinda. Is throttle plate worn out?

 

there was gap between the sides of the plate and bore, but not humongous.
just because it idles nicely and low with threads to spare on the idle set screw im assuming thats not an issue.

i agree its most likely an electronic issue.

 

finally found a diagram to notice: YES, the fpr vacuum line goes through a VSV...
which is not how the lines are run on my truck.
I will re-route my lines when i get home today....
wonder if this might explain anything...

 

yes by flash i mean pull batt cable, have u looked at the 02 sensor?

 

Yes, VAFM issues would definitely cause crappy running if running at all. Also check your wires to the VAFM.

 

Ill look for a post tonight see how it goes

 

no, but efi fuse has been pulled at times to reset codes.

no, i havent looked at the o2 sensor but from the symptoms i kind of doubt it. the o2 sensors provide no input during open loop, which at times have issues too.

ill check the ohms tonight on the afm, aside from a visual check, is there an easy way to check wires aside from measuring to the ecu pinouts

 

ahhhh... my 3.4 (i kno its different lol) was having power issues, weird idle, jerkin real bad all sorts of shizzy an it was bad 02s. just a thought good luck

 

i think i fixed it.... at least i fixed another thing....

followed the wires for the afm, everything looked good.
pryed open the siliconed lid on top, and found one of the pins inside was bent over and barely touching another pin.... no idea how that could have happened, since it was still a distance away from the wiper arm, but it was as if the wiper arm had knocked it over.
bent it back to what i assume is the right shape, and it runs great.

obviously i'll have no idea if i fixed it or not until it goes bad again, but right now im pretty hopeful.

 

oh yea, hooked up the fprvacuum lines correctly, but no change as far as i can tell.

 

looks like it fixed it. havent had a single issue yet.

on a side note. once i hooked up the fpr vacuum through the vsv, i lost power. felt maybe it was running a bit on the lean side.... so i went straight from intake plenum to fpr, and now it feels good. so gonna keep it that way