idle adjustment on TBI + window switch

Discussion in 'The Garage' started by FlatBlackBurb, Mar 29, 2007.

  1. FlatBlackBurb

    FlatBlackBurb 1/2 ton status

    Mar 23, 2007
    Likes Received:
    Santa Cruz, CA
    hey as some of you might know i have a 1987 suburban i just got and it's sick. painted it flat black and gave it some exhaust. just swapped the messed up brake boost with one from a '78 yesterday and it works much better now. im getting a 4'' suspension lift next weekend and ill post some pics up.

    but i still need to get it smogged... i took it in a couple days after i got it and the guy was like "oh it idles too high. the machine won't even read it. also your timing is off". so i was like okay. when i got my exhaust, the guy timed it for free and i notice a small difference in the idle but not much at all.

    my friend is coming over later today and we're going to try and tackle adjusting the idle ourselves. hes got a manual for the generic 80's chevys and were gonna follow it step by step and see where it takes us. any advice from people who have adjusted a TBI idle in the past? it idles just fine when your in drive, but when you switch it into park the idle goes up for some reason.

    also, my drivers window doesn't roll down. its cracked just enough to make a really annoying noise at 40+ mph. i tried taking off the door panel and messing around with the switch, but all of my best efforts were put to shame when i turned the truck on and the window still didn't work. there was a "twist off" blue cap on the window switch, i took that off and then took the connections off only leaving the black board with the copper prongs on it still on the door. how do i get that black thing with thr prongs out? i want to physically take a look at the switch but can't seem to get to it. bad motor? bad switch? can i just swap window motors from a working window to the drivers window? how?

    any tips would be appreciated

  2. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Dec 14, 2001
    Likes Received:
    Pleasanton, CA.
    1987 was the first year for TBI and you need to disconnect the EST wire before trying to time the engine. I would first disconnect the wire and check your timing. If the timing is correct then you can adjust the idle speedo by making the adjustment with the little screw on the TBI unit but afterwards you need to readjust the TPS switch.

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