1st post. i did search and still i'm a little confused on the egr. i've got a 94 4x4 22re 5 speed with a/c 152k miles and i've got the surging idle problem mainly when the truck is warm and pinging(?) when going up hills. i've cleaned iacv,throttle body and egr vacuum modulator. replaced coolant,sparkplugs,wires,pcv (and valve cover gasket,pcv was a bitch!) check valve in brake booster vacuum line and have checked every vacuum hose with a spray bottle with soapy water. i've no CEL. after some searching on here i plugged the vacuum hose to the egr and adjusted idle screw up a little and it seemed to run a little better and now i have a CEL. does this mean the egr was working before i plugged it? is there a way to check egr for proper operation? am i missing something else? also when i had throttle body off intake was full of black soot or sludge, is this normal?

 

no, shouldn't be any sludge in the intake or TB. clean the whole assy. as good as you can. my idle suddenly started sticking high the other day. i stopped at pepboys for some throttlebody cleaner, sprayed the springs on the outside, and pulled the boot off then sprayed the butterfly inside real good. high idle cleared up in about 5 mins of driving and went back down to 800 again. so make sure that's all clean, or your adjustments to the idle screw will not be accurate.

typically, idle surging is from having the idle set too high. when it hits a certain RPM, a cut off triggers to let it drop, then it repeats.

the FSM has a procedure listed for correctly setting the base idle when the engine is warm, and then for setting the fast idle. you'll need a clip-on tachometer to confirm you're setting it accurately.

review the troubleshooting steps in the FSM. yours is viewable online at ncttora's site as well as a few other places listed on this site.

also when you search, search at google rather than the YT search bar, and you'll probably find the results are easier to sift through. this topic has been covered THOROUGHLY. good luck, we're all counting on you.

 

i cleaned butterfly and linkage and everything else i could reach when i had the iacv and throttle body off. thanks for the FSM link. the Haynes manual is lacking in some areas.