idle setting problem, please advise (already searched)
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Launching!
Joined: Apr 2002
Posts: 224
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From: Southgate, MI
idle setting problem, please advise (already searched) Hey guys,
Sometimes I wish I had jsut left well enough alone on my car. LOL.
Anyway, I did the home port and polish on my throttle body. I was very conservative. Did not do anything around plate circumference. Ever since cam install, car has always idled really rough. I figured while I was in the throttle body, I might as well drill hole larger to fix idle.
Drillign hole worked. I figured, if a little is good, a lot must be better. I drilled hole larger. Well, hole was too large. IAC counts at 0 and fast idle. I read a post about flipping idle screw over and using that for adjustment. I did it. I also read about filling in throttle body plate hole with a rivet. I did this.
I tried using idle screw to get IAC counts between 30 and 50. At about 38, the car is idling way fast, like 1200 to 1500. So, I turn screw in just a hair. Idle goes down, but IAC is at 0. Repeated this several times, never got a good medium.
I have tried a trick I read about, unplugging and repluggin TPS sensor in. That did nothing and my Scanmaster showed TPP at 1 before and after, unless I turn screw. I also tried unplugging and plugging IAC as I have read this resets it. This did nothign either. I also pulled PCM bat and IGN fuses and restarted. This also did not help. I am beginning to think I need a hold in throttle plate and use screw to fine tune IAC, or just make a smaller hole than I had until IAC is between 20 and 50.
Please help. ideas?
Thanks, sorry for long post.
Sometimes I wish I had jsut left well enough alone on my car. LOL.
Anyway, I did the home port and polish on my throttle body. I was very conservative. Did not do anything around plate circumference. Ever since cam install, car has always idled really rough. I figured while I was in the throttle body, I might as well drill hole larger to fix idle.
Drillign hole worked. I figured, if a little is good, a lot must be better. I drilled hole larger. Well, hole was too large. IAC counts at 0 and fast idle. I read a post about flipping idle screw over and using that for adjustment. I did it. I also read about filling in throttle body plate hole with a rivet. I did this.
I tried using idle screw to get IAC counts between 30 and 50. At about 38, the car is idling way fast, like 1200 to 1500. So, I turn screw in just a hair. Idle goes down, but IAC is at 0. Repeated this several times, never got a good medium.
I have tried a trick I read about, unplugging and repluggin TPS sensor in. That did nothing and my Scanmaster showed TPP at 1 before and after, unless I turn screw. I also tried unplugging and plugging IAC as I have read this resets it. This did nothign either. I also pulled PCM bat and IGN fuses and restarted. This also did not help. I am beginning to think I need a hold in throttle plate and use screw to fine tune IAC, or just make a smaller hole than I had until IAC is between 20 and 50.
Please help. ideas?
Thanks, sorry for long post.
Joined: Nov 2001
Posts: 34,631
Likes: 2,557
From: Schiller Park, ILL Member: #317
Stock hole size is 5/32".
Currently I am at 13/64" on the hole and I've never touched the throttle blade screw. This has my IACs around 60. I used to have a 7/32" hole that had my IACs in the 45-48 range, but then the idle would fly way up if I popped it into neutral while cruising. For the most part, the car ran better with the 7/32" hole, but I'm going to see if I can use Edit to compensate for the lesser amount of air with the 13/64" hole. Tuning does more for idle and low rpm stability than anything you can do with the TB blade. I've been doing OK tuning on my own so far but if I can't get it to where I'm happy soon, then I'll probably get a full dyno tuning eventually.
I use JB Weld to fill the hole when I want to change sizes. It works great, but it takes a while to dry so I have two TB blades to play with (use one while the other dries).
Currently I am at 13/64" on the hole and I've never touched the throttle blade screw. This has my IACs around 60. I used to have a 7/32" hole that had my IACs in the 45-48 range, but then the idle would fly way up if I popped it into neutral while cruising. For the most part, the car ran better with the 7/32" hole, but I'm going to see if I can use Edit to compensate for the lesser amount of air with the 13/64" hole. Tuning does more for idle and low rpm stability than anything you can do with the TB blade. I've been doing OK tuning on my own so far but if I can't get it to where I'm happy soon, then I'll probably get a full dyno tuning eventually.
I use JB Weld to fill the hole when I want to change sizes. It works great, but it takes a while to dry so I have two TB blades to play with (use one while the other dries).
