Need Advice on installind Idle Air Control
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Stellar HDF Member
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From: On a Lake, not far from the Gulf
Need Advice on installind Idle Air Control
1998 FLTRI M&M injection. I believe that my IAC is fading. The bike will operate normally. I turn it of, go and restart it, and at times it will rev up to 3000 RPM's, and will not come down. Have cleaned the IAC motor, and throttle body, and restet the ECM and that has helped, but it is becoming more frequent. From what I have been able to research the IAC motor is usually the culprit. I have found a NOS replacement on eBay, and will be switching it out this weekend.
My question is that the instructions say to take a voltage reading for the Throttle Position Sensor using a breakout box, before and after to set the IAC correctly. Unfortunately, one is not available. Has anyone replaced this not doing the voltage reading, and if so, what did you do to set the IAC properly? I know that there is a procedure for setting the cold idle setting. Can I just do that after replacing the IAC?
Please don't suggest replacing it with a carb. I know what my options are for that.
My question is that the instructions say to take a voltage reading for the Throttle Position Sensor using a breakout box, before and after to set the IAC correctly. Unfortunately, one is not available. Has anyone replaced this not doing the voltage reading, and if so, what did you do to set the IAC properly? I know that there is a procedure for setting the cold idle setting. Can I just do that after replacing the IAC?
Please don't suggest replacing it with a carb. I know what my options are for that.
Road Warrior
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From: Cave Creek, AZ
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From: Ohio
I tried setting the IAC with a volt meter by tapping into the terminals at the duetsh connecter and didn't work out. You will have the air cleaner off anyway, key on and off several to make sure the new IAC motor moves consistantly to the same spot and adjust the setting screw so the butterfly's just barley moves when the IAC touches, key on and off again to recheck consistancy. Start it up to check idle speed, set it to 200 rpm higher than your desired rpm, when you put your air cleaner back on it will fall back 200 idle rpm.
If it needs a little tweaking, with the engine shut off you can reach the screw (air filter on) with a long allen wrench, turn the throttle grip to access the screw, start it up again, the IAC will be released by the ECM quickly, so you might have to use a couple cold morning start ups to be perfect - do your fuse deal for the ECM to relearn the new position and hopefully all is well.
If it needs a little tweaking, with the engine shut off you can reach the screw (air filter on) with a long allen wrench, turn the throttle grip to access the screw, start it up again, the IAC will be released by the ECM quickly, so you might have to use a couple cold morning start ups to be perfect - do your fuse deal for the ECM to relearn the new position and hopefully all is well.
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Stellar HDF Member
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From: On a Lake, not far from the Gulf
Thanks 1997 Bagger, I was thinking exactly along the lines you did of tapping into the Deutsch connecter. I do not know why that would not work, but thanks for saving me the time. I have read the cold idle setting instructions a number of times, and think that I understand them. Thank you also for the tip on setting it +200.
Any other tips from someone that has actually done this would be appreciated.
Any other tips from someone that has actually done this would be appreciated.
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From: Ohio
The TPS tap-in (alligator clip needles) didn't read right on a TC by the volt method that was giving a buddy some trouble, I didn't want to probe the connectors anymore for damage reasons and went to the manual method. His problem was the IAT was covered with oil and the bike would lose it's hot idle, cleaned it and went ahead and set idles, you have already cleaned your system but using this for referance if anyone else has some fast/cold idle issues.
I didn't have any trouble reading the volts at the TPS on my EFI when I was setting up the Wego3 tuning system, I did it a couple of times with the VOM and had clear accurate volt readings, it could of been mechanic error on the volt reading problem that I posted above.
I didn't have any trouble reading the volts at the TPS on my EFI when I was setting up the Wego3 tuning system, I did it a couple of times with the VOM and had clear accurate volt readings, it could of been mechanic error on the volt reading problem that I posted above.
Last edited by 1997bagger; Oct 5, 2010 at 01:54 PM.
6th Gear
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Also check for intake leaks as those sometimes cause similar behavior. Spray ALL around the TB and intake connectors and listen for that same change in engine idle. Do it cold and hot to make sure.
Over on Harley Tech Talk there a bunch of techs who are familiar with the M&M system. They may be another source of help for you too.
Over on Harley Tech Talk there a bunch of techs who are familiar with the M&M system. They may be another source of help for you too.
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Seasoned HDF Member
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From: Ohio
i think this will help u.....
http://www.youtube.com/watch?v=NBMT53dxq8o
http://www.youtube.com/watch?v=NBMT53dxq8o
Stellar HDF Member
Joined: Feb 2007
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From: Russellville, Arkansas
If the IAC moves at all...it is working and no need to replace it. This part either works or does not work.
Once the TPS setting is correct, it rarely ever goes out of adjustment.
If I was you, I would go through setting the hot/cold idle setting again and check for vacum leaks. Also, make sure the throttle body is clean.
The best way and only way I have ever gotten the hot/cold idle correct....
Get the bike fully warmed up
Set hot idle to about 1,000 RPM
Shutoff engine
Disconnect IAC
Restart bike and set to about 1,500 RPM
Shutoff engine
Connect IAC
Disconnect battery
After the procedure and best when the bike is stone cold. Start the bike, the RPM should quickly rise to about the cold setting you set which should be around 1500. It then should quickly lower itself to about 1000.
Once the TPS setting is correct, it rarely ever goes out of adjustment.
If I was you, I would go through setting the hot/cold idle setting again and check for vacum leaks. Also, make sure the throttle body is clean.
The best way and only way I have ever gotten the hot/cold idle correct....
Get the bike fully warmed up
Set hot idle to about 1,000 RPM
Shutoff engine
Disconnect IAC
Restart bike and set to about 1,500 RPM
Shutoff engine
Connect IAC
Disconnect battery
After the procedure and best when the bike is stone cold. Start the bike, the RPM should quickly rise to about the cold setting you set which should be around 1500. It then should quickly lower itself to about 1000.