lothos Posted May 16, 2008 Report Share Posted May 16, 2008 Anyone in Minnesota or Wisconsin have the IAC adjustment tool? My IAC hunts for an idle when I turn the car off, I can feel the gas pedal move and hear it from under the hood. I got the I027 once as well, with a rough idle. I think it's just out of adjustment and would like to try to adjust it before I go replacing it. WARNING: I'm a total car newbie, don't be surprised if I ask a stupid question! Just trying to learn. Cheers! 5% discount code at RockAuto.com - click here for your discount! Link to comment Share on other sites More sharing options...
Ranger Posted May 17, 2008 Report Share Posted May 17, 2008 You don't have an IAC (Idle Air Control) valve. You have an ISC (Idle Speed Control) motor. There is no "adjustment tool". With the engine idling, press on the plunger till it fully retracts. When it bottoms out, pull the plug. The RPM should drop to about 450 RPM (may stall). Adjust the plunger to a .060 gap with the throttle linkage. If it continues to hunt or ratchets when shut down, it's time to replace it. Link to comment Share on other sites More sharing options...
lothos Posted May 17, 2008 Author Report Share Posted May 17, 2008 Ah, thanks for the clarification. In my FSM the index says ISC, SEE IDLE SPEED CONTROL (MOTOR). There's no listing for Idle Speed Control Motor. Under Motor, ISC it says the same thing. Can't find it in the book. How am I supposed to gap it to .060? Is it similar to gapping a spark plug? WARNING: I'm a total car newbie, don't be surprised if I ask a stupid question! Just trying to learn. Cheers! 5% discount code at RockAuto.com - click here for your discount! Link to comment Share on other sites More sharing options...
lothos Posted May 17, 2008 Author Report Share Posted May 17, 2008 Still can't find it in the FSM but I found some instructions that I can print off and use. Thank you Ranger for your clarification and help. WARNING: I'm a total car newbie, don't be surprised if I ask a stupid question! Just trying to learn. Cheers! 5% discount code at RockAuto.com - click here for your discount! Link to comment Share on other sites More sharing options...
Ranger Posted May 18, 2008 Report Share Posted May 18, 2008 The plunger screws in and out. Adjust it to a .060 gap. Link to comment Share on other sites More sharing options...
lothos Posted May 18, 2008 Author Report Share Posted May 18, 2008 I just finished the diagnostic tree procedure in the FSM. Car stalled. Measured the outputs like the book said, I subtracted my minimum value of -.5 from the max value of 7.5 and got 8.0. That's below the 10 - 11 that it should be, book says to extend the plunger by turning counter-clockwise and re-test. I can't find the plunger any pointers? Other posts on the forum here say the gap should be .030, which is correct? WARNING: I'm a total car newbie, don't be surprised if I ask a stupid question! Just trying to learn. Cheers! 5% discount code at RockAuto.com - click here for your discount! Link to comment Share on other sites More sharing options...
Ranger Posted May 18, 2008 Report Share Posted May 18, 2008 The plunger is the hex headed bolt that sticks out the end of it and contacts the throttle linkage. I could have sworn it was .060, but if general consensus is .030, go with that. Link to comment Share on other sites More sharing options...
lothos Posted May 19, 2008 Author Report Share Posted May 19, 2008 I adjusted it until the diagnostic tree told me it was within range. Doesn't seem to be hunting any longer, I'll keep an eye on it. If it needs replacing will it cause any surging? Or just a rough idle? All the turning on and off of the key must have done something to the power antenna, it's stuck up right now. I can still hear the antenna motor activation. I suspect it just came undone from the cable or whatever, going to look into that. WARNING: I'm a total car newbie, don't be surprised if I ask a stupid question! Just trying to learn. Cheers! 5% discount code at RockAuto.com - click here for your discount! Link to comment Share on other sites More sharing options...
Ranger Posted May 19, 2008 Report Share Posted May 19, 2008 A bad ISC motor will not cause a rough idle. It will surge or "hunt" for the correct idle RPM. Unplug the antenna till you figure it out so you don't burn up the motor. The cable inside may have broken. Link to comment Share on other sites More sharing options...
lothos Posted May 19, 2008 Author Report Share Posted May 19, 2008 Will it cause the car to buck? Is it unsafe if it goes bad? Thank you very much for your help! WARNING: I'm a total car newbie, don't be surprised if I ask a stupid question! Just trying to learn. Cheers! 5% discount code at RockAuto.com - click here for your discount! Link to comment Share on other sites More sharing options...
lothos Posted September 5, 2008 Author Report Share Posted September 5, 2008 I replaced my ISC earlier this week with a new ACDelco unit from rockauto. I ended up leaving the ISC bracket on the car (because I didn't have a big enough six pointed screwdriver), and undoing the bracket that holds the cruise control to get a little more space. The GearWrench set that I bought came in handy for the 8mm bolts. The GearWrench wouldn't fit in to reach the third bolt so I ended up using a shorter 8mm wrench. I'm glad I didn't drop any of the bolts, the new ISC didn't come with bolts to attach it to the bracket. I did drop the small 8mm wrench into the engine bay two or three times, and had to use a telescoping magnetic parts retriever to get it. The parts retriever can lift up to 3 pounds and was on clearance at Checker Auto Parts for $1.50. I picked it up on impulse, and I'm glad I did because it came in really handy. The idle is a lot smoother now. I disconnected the battery so the car could learn it's idle, and I got the regular codes for a disconnected battery (P052, P109, I052) that I cleared out. I tried to gap the actuator correctly but I'm not sure I got it right. When my ISC was hunting for an idle before, I used the computer to adjust the ISC until it was within the right range. I noticed the new ISC adjusting after shutdown once, and I'm not sure if it needed to find the idle and will be ok now. If it keeps doing it I'll use the same procedure out of the FSM to get it within range again. This was my first time doing this, and it took about 2 and a half hours WARNING: I'm a total car newbie, don't be surprised if I ask a stupid question! Just trying to learn. Cheers! 5% discount code at RockAuto.com - click here for your discount! Link to comment Share on other sites More sharing options...
BodybyFisher Posted September 5, 2008 Report Share Posted September 5, 2008 Will it cause the car to buck? Is it unsafe if it goes bad? Thank you very much for your help! Explain Buck?, hesitation? On acceleration? Are you getting any codes? The TPS can cause a hesitation, but I think you would get a code Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
lothos Posted September 5, 2008 Author Report Share Posted September 5, 2008 Will it cause the car to buck? Is it unsafe if it goes bad? Thank you very much for your help! Explain Buck?, hesitation? On acceleration? Are you getting any codes? The TPS can cause a hesitation, but I think you would get a code Nah, no codes. I was just wondering if the ISC could cause the car to surge at idle if it was bad. I got it replaced though, it seems to idle pretty good now. I had a hesitation on acceleration, where I pushed the pedal down and the car fell on it's face and wouldn't accelerate much at all. It happened twice over the summer. I also had surging at idle maybe three times, and one time the car died pulling into work. I think my FPR was bad, ordered a new one from rock auto. When I replaced it the old FPR came apart in my hands. Haven't had any weak acceleration or surging since, so hopefully that was the problem and not the fuel pump. EDIT: Oh, I sometimes get some surging from the undercarriage wash at the car wash. I think I need a new tensioner. I have a belt but I'm going to wait to put it on til I get a new tensioner. That might have been the cause of my surging too, I don't remember if it was wet out or not when it happened. WARNING: I'm a total car newbie, don't be surprised if I ask a stupid question! Just trying to learn. Cheers! 5% discount code at RockAuto.com - click here for your discount! Link to comment Share on other sites More sharing options...
rek Posted September 5, 2008 Report Share Posted September 5, 2008 Do you have a Delco P/N for a six pointed screwdriver? rek Link to comment Share on other sites More sharing options...
Ranger Posted September 5, 2008 Report Share Posted September 5, 2008 I think he must mean a Torx head screwdriver. Link to comment Share on other sites More sharing options...
lothos Posted September 5, 2008 Author Report Share Posted September 5, 2008 Do you have a Delco P/N for a six pointed screwdriver? It's a Torx head, sorry I didn't know what to call it WARNING: I'm a total car newbie, don't be surprised if I ask a stupid question! Just trying to learn. Cheers! 5% discount code at RockAuto.com - click here for your discount! Link to comment Share on other sites More sharing options...
lothos Posted September 6, 2008 Author Report Share Posted September 6, 2008 Went through the diagnostic tree for the ISC and it was out of range. I spent some time and got it exactly in the middle of the allowed range, and we'll see how it does. I also did the idle learn procedure. WARNING: I'm a total car newbie, don't be surprised if I ask a stupid question! Just trying to learn. Cheers! 5% discount code at RockAuto.com - click here for your discount! Link to comment Share on other sites More sharing options...
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