PROBLEM FIXED!!

[KORNBREAD]

ok after my last post called "PLEASE HELP!!" i replaced the EGR valve, map sensor,02 sensor,coolent temp sensor,new plugs,wires,cap,did full rebuild on my throttal body with new fuel presure regulator,all new gaskets from the base where the tbi and intake meet up,and all new vacume lines. now the k5 will start right up and run amazing and very smoth but when its time for the high idle to kick down it dosent! if i romp on the throttal it kicks down sometimes for a real quick second but climbs right back up again. im totaly lost. it will fire right back up and i got the flooding of the tbi to stop but when i start it, it jumps right to high idel and wont kick down. please help!  for more info on the problem i first had with it read my topic called PLEASE HELP!  ..........................WOW I DESERVE A HUGE KICK IN THE BUT LOL............................I CANT BELIVE I DIDNT SEE THIS BUT WHEN I PUT EVERYTHING BACK TOGETHER FROM REBUILDING IT THERE A SENSOR PLUG THAT PLUGS IN TWORDS THE BACK OF THE TBI AND I TUCKED IT BACK UNDER THE WIRE LOOM WHEN I PULLED THE TBI OFF BUT WHEN I HOOKED EVERYTHING BACK UP I DIDNT SEE THAT PLUG AND NEVER PLUGED IT IN. I WAS ABOUT TO TAKE THE TBI OFF AGAIN TODAY AND WHEN I CLIMBED IN THE MOTOR COMPARTMENT I SEEN THE PLUG LAYING IN THE BACK!

[RIP_K52007]

you sure ya got the EGR tightend down and didnt strip the hole out?... just asking cause my 4 cyl s10 does that and thats why. ... ummm....

other than that.... is your throttle cable letting it return all the way to idle position?   

go over the vacuum system real close ... even heater controls (i think bigger orange vacuum line goes threw firewall and into dash, supplys the vacum to the mode selector switch), i cant remember what year your k5 is.. but any vacuum leak will mess with'em.

[KORNBREAD]

ill check the idle screw today. and yes the check engine light was on all the time when this happened but after all i did to it it comes on just when the high idle should kick off but the light shuts off after about a min. also yes the egr is tight. i have been all over this engien so many times i get sick of seeing motors all together lol.  i got it running amazing but this damn high idle wont go away!!

[betterbeaters]

check your intake gaskets........   I had one blow and it made it idle high

[chevystudz7105]

take some starting fluid and spray it around on the intake.  if you have a leak somewhere  the rpms will go up more then what it is running at.  seen people do this to find vaccum leaks

[KORNBREAD]

ya i did that from the get go. thats why im so stumped. no leaks and all new sensors and still high idle! im so lost lol!

[mudslayer2008]

check the arm on the throttle where the cable hooks to it there should be an adjustment for the throttle cable if there is make sure it is not adjusted to tight to hold the throttle plates open.
    ( I had this happen to my 94 when I changed the motor.)

[KORNBREAD]

its not that cause the truck ran great till it died last week.

[Econo-box from Hell]

Send it to me, I'll figure it out.

[blasterguy911]

clear the code.

[Disturban]

clear the code.

Yes...then if it comes back scan it! Also make sure your throttle blade is closing all the way...if you have so much as a grain of sand in it that keeps it from closing all the way you will experience high idle.

[KORNBREAD]

is there any other way to clear the code besides reseting the computer? iv unhooked the battery and let it set over night so today ill go out and try that again. i was also told to take it for a drive and give the computer time to readjust itself. so ill try that also today. i also totaly cleaned the crap out of the throttal body when i rebuilt it. it was pertty damn dirty.

[blasterguy911]

if you take it to advanced auto or auto zone they will clear it

[Disturban]

What year vehicle? 1996 and newer OBD2 and have to clear it with a scanner. 1995 and older OBD1 you can clear by disconnecting battery.

Some 1995's have OBD2 computers.

[RIP_K52007]

What year vehicle? 1996 and newer OBD2 and have to clear it with a scanner. 1995 and older OBD1 you can clear by disconnecting battery.

Some 1995's have OBD2 computers.

i think they quit making k5's in like 93 or 94.

[KORNBREAD]

ya its a 87 so its a obd1.

[Disturban]

How high is the idle? 800? 1000? 1500? I seen on a show where the throttle blade was stuck just a little and it caused your problem. On the other hand I never rebuilt a TBI but I would imagine that they have an idle passage or something like that and I bet ya have some debris or chunk of carbon ect ect blocking something. Or you may not have something adjusted right. Another thing is the throttle position sensor, I was checking out mods for TBI and one involved drilling out the mounting holes for the sensor so when the bolts are loose you can turn it alittle clock wise or counter. I guess this mod gives ya better throttle response? Who knows...but what I am getting at is when you installed the Throttle position sensor maybe there was enough room in the bolt holes to turn it just a hair...that might make a difference.

[Econo-box from Hell]

If it is TBI there is a 90% chance you have a vacuum leak.  One place people overlook for vacuum leaks is the brake booster.  Block all vacuum ports and see if the idle drops.  Another place  these get vacuum leaks is the throttle body gasket.  Spray some NON-flammable brake cleaner at the base and see if the idle drops (warning, this stinks when it goes through the motor).  One last think I can think of is the idle control motor.  Sometimes the plunger will not seal on the seat properly.  Take the ICM off and block the bypass port and see if the idle drops to almost nothing.  I've also seen the ICMs only go in one direction or the other because the wiring to it is screwed up and will only send signal one way.

Once again, if you can't figure it out, send it to me.  Since my "full time" job consists of about 25 hours a week, I am trying to earn cash-O-la from wherever I can.

[KORNBREAD]

ill try plugging the vac lines and see what that dose. i sprayed all the gasket areas when this first happend and no change. even after i replaced them all still nothing. today was the first time i drove it sence i replaced everything. it drives so smooth like a new truck. dosnt over heat,shifts great,runs really strong! but the damn high idle still wont drop. i would let ya help econo but im straped for cash. thats why im doing all this myself and teaching my self how to rebuild tbi's,and all that to keep cost down.  so do i just unplug all the vacumes from the tbi and start it? if so then what do i do? do i start pluging them in one by one to see if it changes?

[Econo-box from Hell]

One by one will work.  Next time you spray stuff to find a vacuum leak use non-flamable brake clean or carb cleaner.  The idle change will be more noticable if you find a leak.  Don't forget to isolate your power brake booster.