why is it not typical? because i searched this site for 2 hours and, yes, i checked for vacuum leaks thoroughly(propane method) and so your knee-jerk answer (its a vacuum leak) does not apply.
like the other victims of the high idle after installation of new/bored out tb, my idle is high. at first, it was around 3k, and it was slow to drop revs after gassing it. this is the iac motor not working right. so i put in another iac, this one was retracted and i didnt know any better at that point, so of course, being retracted and not reset, it idled real high, like 6k. i put the 3k iac back in, searched, found out you can pull the MAP sensor plug until the car dies, then restart with the key still on, and it should reset your iac.
after doing that, my idle dropped to between 1500 and 2k and the revs would drop after gassing it, actually would drop to about 1200, which was a step in the right direction. but immediately after dropping after gassing it, the car jumps back up to a 1500/2k idle.
also, when driving, the idle may climb to 3k and will only drop back to 1500/2k after goosing the throttle.
i am throwing cel codes for the iac and for high voltage at map sensor. i know someone had the same problem, and swapped their tps and the problem went away. i unfortunately have to go buy a hand impact wrench as the tps bolts claim yet another group of my torx tools.
but the thing is, i checked the tps i have on my car with a multimeter, and it was within range! yet another search had a person claiming the tps is on the same circuit on the map, so who knows, maybe it is the problem. also, i have a 95, and the sensors that were originally on my car have the same part numbers, minus additional numerical suffixes that were on the sensor/iac that came with my bored tb that are on the car now.
also, once i learned about the iac, i swapped back and forth, pulling the plunger all the way out and resetting each time, and the idle problem is the same for each one.
so....
vacuum problem - not a factor
tb - lined up to intake mani perfectly
throttle cable - butterfly closed at idle so not a throttle cable adjustment issue
butterfly valve - suspect as there is a slight "corona" when holding it up to the light, but my searches have shown people with bored tb's often have a <1mm gap and their idle problem was almost always something else and was corrected while the butterfly stayed the same
iac - obviously something wrong here, but why does it respond to the map plug pull (as far as dropping revs) but idle is still high?
its like the car knows to drop to correct idle after letting off the gas, but the ecu decides to come in at that point and raise the idle again.
basically, if you have any further ideas, please let me know. i have reset the pcm via battery disconnect, but it doesn't change anything, doesnt even erase the cel for one start. so i think i am facing a sensor/iac/pcm problem. off to sears for a impact wrench i go, so i can swap the tps, but please, please, please, if you have any suggestions i have not covered, or know a way to solve this outright, please let me know. as you can see i have searched, and have only one solution left from my searches, if that doesnt work, i am sol.

Proud owner of a '95. Johnny Tran says the '95 VTEC just kicked in, yo.


RICE: AEM Short Ram, CI 55mm Throttle Body, GS-T Muffler, Self-Made Ground Wire Kit, Caulk, Duct Tape,
and "Stage 1 Weight Reduction" aka screws and bolts always left over from working on car.

swapped the tps and there is no difference. reset ecu via battery unplug and now only throwing a iac cel. pulling the map sensor is not resetting the iac, solving the problem, or getting rid of this cel. am i stuck taking it to satan for an iac reset, or is there another way to reset the iac and clear the cel and solve my problem? will an obd1 (i have a 95) or another scanner do this for me? the chilton manual explanation for resetting the idle is just dead wrong, even has the wrong pictures of parts.

HELP!!!!! all leads found searching this site have not solved this problem. double-checked vacuum leak, that is not it, double checked butterfly valve, butterfly valve is not it.

Proud owner of a '95. Johnny Tran says the '95 VTEC just kicked in, yo.


RICE: AEM Short Ram, CI 55mm Throttle Body, GS-T Muffler, Self-Made Ground Wire Kit, Caulk, Duct Tape,
and "Stage 1 Weight Reduction" aka screws and bolts always left over from working on car.

just move the IAC pintle by hand till its right if you think the IAC is still the problem. pull it out a little further and see if the idle speed drops.

1998 dodge avenger 4 cyl AT
Mods are:
Not enough

thanks for the suggestion, but i have already done that.

twice.

i pulled it out so far that it wouldnt even stay that far when it went back in the tb because it was pulled out more than it has room for. to make sure it wasnt a gunked out tb or fitment issue, i tested it on my other tb, same thing. so pulling out the iac further has been tried. trust me, i am obsessive and spent the entire weekend messing with everything.

checked vacuum, again, no vacuum issue. did a lot of testing all day long, even reset the ecu and let it idle for 45 minutes to see if it would adjust. no go, just a high idle and an iac cel. i am left to face the fact that i messed with something i shouldnt have, and now i have to buy a scanner that is capable of resetting the iac, or i have to pay someone else to do it, because at this point i have tried everything anyone has ever posted on this site at least twice to no avail. it is a computer error resulting from moving the damn iac while it was out of the tb. i live on the sussex/morris county border in new jersey, so if anyone has the tools to reset the iac bs in the ecu, i.e. obd scanner, etc., please "holla". make sure to state your favorite beer. otherwise, please suggest a shop in the area that can do it for me.

yes, free beer to the one who can fix this.

Proud owner of a '95. Johnny Tran says the '95 VTEC just kicked in, yo.


RICE: AEM Short Ram, CI 55mm Throttle Body, GS-T Muffler, Self-Made Ground Wire Kit, Caulk, Duct Tape,
and "Stage 1 Weight Reduction" aka screws and bolts always left over from working on car.

http://www.murderpimp.com





2gnt T-shirts&swag
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you need a drb3 tool to reset the IAC motor position.
have you blocked off the EGR valve yet? that can cause high idle too if it gets stuck open, which happens alot

1998 dodge avenger 4 cyl AT
Mods are:
Not enough

http://www.murderpimp.com





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you can just reset all the codes by disconnecting the negative battery lead, no need for a scan tool. obd2 or drb3.

But Im with you I just think he needs to move the pintle around some more till it is in the right place.

IMO pull it out all the way and dont connect the narness for it and see if the idle goes down, that will tell you right away if its the IAC or not. if the idle is still high its something else.

1998 dodge avenger 4 cyl AT
Mods are:
Not enough

i should have done it that way, because that would have been the smart way!

instead, i have swapped in 2 different iac motors at different lengths, multiple times, and the idle did correspond with the length of the plunger each time, so this is the way i determined that the iac motor was the problem.

yeah, i tend to do it the hard way!

i also did the battery disconnect and it did nothing, i even let it idle for 45 minutes afterwards hoping the ecu would "wise-up" but it didn't.

madhatter looked up the obd1/obd2 issue regarding a 95 and came up with the following
http://forums.2gnt.com/dcboard.php?az=show_topic&forum=4&topic_id=41582&mesg_id=41582&listing_type=search

so i am meeting up with madhatter today to use his obd to reset the iac, and if that doesnt work, i have an apt with a family friend mechanic to go over everything and use the shop scanner. and if THAT doesn't work i am going to put a 6 foot wing on my car so when people look over to see who is revving so high at a stoplight, and to see where the smell of burning clutch is coming from, they can see my rice-a-roni wing and figure it out right away.

anyway, thanks for the input mcgyvr. at least in the future someone will search and find your info in one place, instead of searching for it all over the place like i had to. i will report on the results of this afternoon for future reference.

Proud owner of a '95. Johnny Tran says the '95 VTEC just kicked in, yo.


RICE: AEM Short Ram, CI 55mm Throttle Body, GS-T Muffler, Self-Made Ground Wire Kit, Caulk, Duct Tape,
and "Stage 1 Weight Reduction" aka screws and bolts always left over from working on car.

http://www.murderpimp.com





2gnt T-shirts&swag
http://www.cafepress.com/mads

1998 dodge avenger 4 cyl AT
Mods are:
Not enough

this is a doozy....got it figured out!

met up with madhatter (thanks again!) and plugged in the obd 2 and cleared the cel, unfortunately could not do more. the cel came right back and madhatter gave me a look like "you poor bastard, that's all i can do"
i was like, oh crap. ps, i bought the tb core off madhatter and he came out to help me forgetting i was the one that bought it. genuine good guy.
so next i took it to American Automotive in Wharton, NJ as I know the owner. He used the carb cleaner method to hunt for vac leaks, so now my propane and his carb cleaner turned up nothing. he has a machine that manually moves the iac.....

up, down, up down, nothing......

so the iac is not the problem, vac leak right? wrong. i didn't know any better, AND many people on this site have said some gap between the butterfly valve and the tb bore is ok.

nope. i swapped my bored tb for my stock, and using the same tps and iac, no ecu reset, no adjustment whatsoever, the stock tb worked perfectly. i still have a iac cel but i will clear it once it stops raining.

so the problem was butterfly valve gap, ladies and gentlemen. i am sending it to get fixed tomorrow. see, the butterfly valve is letting air by, and the computer does not expect the tb to have been changed, of course, so it tries to manipulate the iac to figure out the excess air, and it throws an iac cell because of course, the programming figures the plastic iac went bad, not the hardass metal tb. thats why the idle whacks out while driving and goes crazy after driving, the mapping doesnt make any sense to the computer. poor computer.

so if you get your tb bored, make sure the butterfly valve closes and is centered and has no gap. i contacted the people who did my work and they told me to send it back and they will fix it. as a side note, putting the stock tb back made me realize how nice of a mod this is. your butt dyno will feel a difference! just make sure the work was done right before putting a new tb on. any gap present should be 1/1000 of an inch, not really visible. like thinner than paper. anything more and you are no go. I now proclaim myself a know-it-all for tb problems as i have literally checked and rechecked every possible install problem before arriving at the solution. feel free to pm me if you need help, i would like to give back to the board.

THANKS TO MADHATTER, MCGYVR and ALL PREVIOUS POSTERS. SAY NO TO GAP. DON'T TOUCH THE GODD@#N IAC. BE EXCELLENT TO ONE ANOTHER.

Proud owner of a '95. Johnny Tran says the '95 VTEC just kicked in, yo.


RICE: AEM Short Ram, CI 55mm Throttle Body, GS-T Muffler, Self-Made Ground Wire Kit, Caulk, Duct Tape,
and "Stage 1 Weight Reduction" aka screws and bolts always left over from working on car.

The ECU tries to shoot for a target idle speed. If that can't be met, it will trip the IAC code, because it thinks that the IAC isn't functioning properly. Basically what is happening, is that the ECU is trying to completely close the IAC to lower your idle, but even with the IAC closed, it still idles higher than the target idle speed since there is too much air getting by the throttle plate, and trips the code. Good to see you have it figured out. Issues like this can get frustrating

13.5 @108 MPH-2.2 60ft(stupid FWD!)
S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential
fuel injection)
My webpage: http://eclipsed4evr.home.comcast.net
-1998 Mitsubishi Eclipse RS-T- "Toy"
-1992 Plymouth Laser Turbo AWD(SOLD)
-2000 Honda CR-V(daily)

http://www.murderpimp.com





2gnt T-shirts&swag
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you have been one of the more helpful people on the board, and i think it is really cool that you were willing to take the time to help in real life, so don't worry about the beer. the money i save by getting help here offsets any overhead (beer). Thanks again!

Proud owner of a '95. Johnny Tran says the '95 VTEC just kicked in, yo.


RICE: AEM Short Ram, CI 55mm Throttle Body, GS-T Muffler, Self-Made Ground Wire Kit, Caulk, Duct Tape,
and "Stage 1 Weight Reduction" aka screws and bolts always left over from working on car.