help with engine problem

[Destroyer000]

my buddy has a 96 ranger 4.0. we recently just replaced the valve cover gaskets and the plugs an wires.. well now thiers another problem.. at idle the truck surges goes up a lil bit then drops below 1k an just flat out dies.. does this after its been warmed up a little bit.. i thought it was the iac valve an replaced it an that wasnt the problem. next i cleaned the maf sensor an its still doing it.. now with the maf sensor when the truck bogs down an starts to die if i unplug the maf it tacks back up.. iam stumped on what could be wrong any one have an idea?

 

[metalmacguyver]

what kind of plugs did you put in?

 

[Destroyer000]

well i just got a code scanner from my buddy an its throwin a po171 bank 1 too lean.. now bank 1 would be driver correct? what would cause this problem?

we put the autolite platinum plugs in it

 

[klogtruck]

sound's like it mite be a vacum leak

 

[metalmacguyver]

autolites are good plugs. they manufacture the oem motorcraft plugs. i have heard of people having bad results with some of the bosche crazy hitech plugs.

+1 on the vacuum leak
(i didnt know how to actually spell vacuum until just now when i looked it up. doesnt spell the way it sounds.)

perhaps you missed something when you were reassembling everything. also, if a vacuum line somewhere was worn out or rotted or something, then just moving it may have torn it slightly.

 

[Destroyer000]

well i sprayed some carb cleaner around the intake an sure enough a leak.. its leaking at the egr tube .. wasnt quite in all the way. so i took e a block of wood an gave it a tap an in it went.. runs better sprayed some more carb cleaner at it an its still got a TINY leak so i put a dab of silicone around it..