RPM Help

Dennis Christensen · Feb 19, 2012

I just put on a 75mm accufab throttle body and intake plenum combo along with some new spark plugs and 410s and an sct tuner with a bama tune. I had to replace the TPS along the process everything went smooth until i took it for a test drive just cruising around and i noticed it idles a little higher and when i shift the rpms slowly drop around 2500 but kinda hang and when i stop it idles high momentarily and then drops down to around around 900. I just unhooked the battery and am going to try again but any advice would be awesome Thanks!

Bullitt347 · Feb 19, 2012

When I did basically the same to my car, it took several drive cycles before the rpm's would drop like normal. It took a week or so before it quit hanging at 1500 to 1800 rpm's for up to 60 seconds and then coming down. It takes the ECU awhile to adapt to the larger throttle body and tune.

slayerripkdc · Feb 19, 2012

When installing mods do one at a time. Take it for a test drive and make sure everything is fine. Don't do everything at once. Makes it harder to diagnose.

Dennis Christensen · Feb 19, 2012

Ok thanks Bullit ya it felt almost like i had cruise control on lol and thanks for the advice for the future slayer!

wmburns · Feb 19, 2012

Did you follow the directions regarding setting the idle stop screw gap? Sounds like to me there is too much air passing at idle. The other possible cause is a vacuum leak. Check all hoses. What about the PVC valve?

Note, unhooking the battery is going to cause the PCM re-learning process to start over. So if it is a cause of learned idle trim values, you are not doing yourself a favor by disconnecting the battery.

Here's more information on how to trouble shoot high idle issues.
http://www.allfordmustangs.com/foru...-dieing-idle-idling-rough-14.html#post2260649

Dennis Christensen · Feb 19, 2012

wmburns said:
Did you follow the directions regarding setting the idle stop screw gap? Sounds like to me there is too much air passing at idle. The other possible cause is a vacuum leak. Check all hoses. What about the PVC valve?

Note, unhooking the battery is going to cause the PCM re-learning process to start over. So if it is a cause of learned idle trim values, you are not doing yourself a favor by disconnecting the battery.

Here's more information on how to trouble shoot high idle issues.
http://www.allfordmustangs.com/forums/4-6l-tech/49661-your-mustang-stumbling-dieing-idle-idling-rough-14.html#post2260649[/quote]

thanks i appreciate it and it didnt come with any directions i pretty much just put everything back the way it was supposed to be and the pvc i tapped in like it said with some loctite.

Dennis Christensen · Feb 19, 2012

thanks i appreciate it and it didnt come with any directions i pretty much just put everything back the way it was supposed to be and the pvc i tapped in like it said with some loctite.

Dennis Christensen · Feb 19, 2012

it will idle fine after a minute i noticed while im driving it will stay at whatever rpms i left off at then it sounds like a little clunk and it drops like normal

Dennis Christensen · Feb 19, 2012

also i took the cai and with the car off pushed the throttle to full and watched it close it closes all the way but then it clunks and seems like the cable might be a little loose is it supposed to be tight? sorry im a newb

Night Shifter · Feb 19, 2012

Fwiw, anytime i load a new tune or reset the current tune on my car it takes around 3 days for the computer to finally learn the tune and drive normal... during the time its learning the idle will either hang or climb between shifts and when coming to a stop..

As stated above, it may take a few drive cycles for the car to go back to normal..everything you have described is exacly how my car wil run for the 1st couple days of a new tune...its annoying as hell but i would bet in a couple days your car will be back to normal

1fun281 · Feb 20, 2012

Advice for everyone on this site, i just did it to my car over the weekend, and i would reccomend it to everybody, i deleted my idle air controller with an IAC plate home made, and tuned the idle off the throttle body screw, pretty much the greatest thing ever done to the car, it has never idled this good especially with a big cam, id reccomend it to everybody, no more hanging idle!

Dennis Christensen · Feb 20, 2012

thanks for the help everyone kind of at a stand still right now the kit says it comes with new iac bolts and well it doesnt am says accufab forgot them and accufab says they never supply those and the old one broke off in the new plenum and cant extract it so waiting to hear from AM and see what they can do hope to hear something tomorrow, on a side note looking to do a supercharger soon any suggestions like it to be loud and be able to hear it whine. Thanks again guys

wmburns · Feb 20, 2012

1fun281 said:
Advice for everyone on this site, i just did it to my car over the weekend, and i would reccomend it to everybody, i deleted my idle air controller with an IAC plate home made, and tuned the idle off the throttle body screw, pretty much the greatest thing ever done to the car, it has never idled this good especially with a big cam, id reccomend it to everybody, no more hanging idle!

For anyone thinking about doing this, don't be surprised when it stops idling with the change of weather. So be prepared to re-adjust the idle depending upon the air temperature. Without an IAC valve, the computer control of the idle is gone. It becomes like a carb but without any of the adjustments that a carb would have.

RPM Help

Dennis Christensen

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Bullitt347

I have been doing it wrong this whole time

slayerripkdc

Dennis Christensen

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wmburns

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Dennis Christensen

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Dennis Christensen

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Night Shifter

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1fun281

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Dennis Christensen

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wmburns

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