Bumping the Idle

Mustangbelle306 · 05-14-2002, 10:58 PM

As some of you may know, I've had my GT in and out of the same, piece of **** machine shop for months now. Well, she went in for the last time a few weeks ago

Anyways...

My problem is, they set the idle so low that it stalls out when I'm sitting at lights. Its sitting around 600 now, and putts out whenever I'm sitting for more than 20-30 seconds. Does anyone know how I can temporarily bump the idle up? I don't have the cash right now to take it in and see what's really going on, but I've watched the mulleted monkey at the shop fiddle around the throttle body before to tamper with the idle...just don't know WTF he was doing?!

Any suggestions???

Thanks again,

Belle

Mach 1 · 05-15-2002, 02:28 AM

Turn up the idle stop screw on the throttle body. Will take you a total of about 15 seconds.

cyberstang5.0 · 05-15-2002, 07:17 AM

That "mulleted monkey" was probably adjusting the TPS (throtle position sensor). There are 2 screws that hold it on the TB. Just take a screw driver and unscrew them just a little bit (enough to move it) and trun the sensor left of right until the car idle's were you want it to. That might help ya out. Also, try unplugging the Idle air bypass sensor (it's that thing that is mounted at an angle on the TB). I did it to my car when I was having idling problems and it worked. Keep in mind, it's just a temporary fix. Hope this helps.

You can always give your car to me

I'll fix it

andy669 · 05-15-2002, 12:24 PM

Turning the idle screw up will only raise the idle temporarily. When you shut the car off and restart it, it will be down again.

Adjusting the TPS is not that easy on the SN95's. The TPS screws are halfway hidden behind the IAC. Furthermore, they are almost non adjustable. They have metal bushings in the mounting holes which makes turning them almost non-existant.

Does the car act any different whether it is cold or hot? I would check for a properly functioning EGR, and vacuum leaks. Does the idle change if you unplug the IAC? If all else fails, just find another shop that has an OBD I scanner. Anyone with experience should be able to find the problem that way. It shouldnt cost more than $60 to have someone scan it. If thats too much, maybe you could sweet talk them a 'lil.... hehehe

andy

LX XLR8R · 05-15-2002, 12:39 PM

there is a special procedure that ya got to follow when setting the idle..i dont rember it cuz its been 4 years sence i had a IAB on my car!..just unplug the stupid thing and set the screw where you want it

Mach 1 · 05-15-2002, 04:00 PM

Quote:

Originally posted by andy669
Turning the idle screw up will only raise the idle temporarily. When you shut the car off and restart it, it will be down again.

andy

Thats interestinga? Manually holding the throttle valve open farther with a stop screw doesnt seem temporary to me?

Mustangbelle306 · 05-15-2002, 05:15 PM

Thanks for the advice everyone, I set the screw eariler (no sweet talking necessary

) this morning with some help from Cyberstang, and I've never heard of a screw manually resetting itself on shutdown

Not sure what you were talking bout...

Car's running MUCH better, for now at least! Makes me feel better about finding out that the AC compressor is shot

andy669 · 05-15-2002, 06:13 PM

Mach Whenever I've tried this on my 94 the idle has always came back down. I just figured it was the computer compensating. But maybe there was something else going on that I wasnt aware of too.

No, Belle I wasnt referring to the screw maunally resetting itself! Geez, do I sound that dumb?

....... Wait, dont answer that!

andy

Green9550 · 05-15-2002, 07:30 PM

I have to say, andy669 is right about the idle fixing itself. Kind of odd. I fixed it by setting my idle at about 1100. It works perfect now. I'm glad you figured your problem out belle. Take care.

-Billy

mysweetlx · 05-16-2002, 04:26 PM

Where should the idle be set at....800? 900? 1000? Is there a performance benefit to the rpm it's set at or is it a personal preference thing?

Mr 5 0 · 05-16-2002, 04:41 PM

Where should the idle be set at....800? 900? 1000? Is there a performance benefit to the rpm it's set at or is it a personal preference thing? - mysweetlx:

An idle RPM of 800 is fine, 900 is O.K. too but anything more wastes gas with no performance benefit at all. Yeah, it's really a personal preference thing.

Green9550 · 05-16-2002, 05:41 PM

Yeah, Mr 5 0 is right. An Idle of 800-850 would be ideal. I have such a high idle because that is the only way my car will stay running. I need to get a chip, that will happen June 7th. Then I'm hoping for an idle of about 850. Take care.

-Billy

fiveohpatrol · 05-19-2002, 06:22 PM

Quote:

Manually holding the throttle valve open farther with a stop screw doesnt seem temporary to me?

thats what i thought too, until i tried it. I set it at 900 one night, went for a drive and it was still at 900 at every stop i made. Then the next morning when i started it back up, it was down to 700.

Its either the TPS or the IAC (or both) that compensates when you set the idle manually and then it sends it back down.

Mr 5 0, I think i've read a post in where you explain the proper way to set the idle. Dont you have to set it with a feeler gage to factory specs, then unplug the IAC while you turn the screw, or something like that?

Mach 1 · 05-19-2002, 07:02 PM

I guess the compter could compensate to a point, but once you turn that screw far enough, the idle will stay up.

Mr 5 0 · 05-19-2002, 07:53 PM

To whom it may concern:

Set the idle screw by loosening the screw until you can fit a .010" feeler gauge between the stop plate and the end of the screw.

Tighten the screw until the feeler gauge comes out with some resistance. Tighten the idle screw 1 1/2 turns more.
Check your TPS to make sure it's about .95-.98v.
If it checks out, reset the computer.

Usually, just driving the car 10 miles or more will reset the ECM.

05-14-2002, 10:58 PM	#1
Mustangbelle306 Yay for Chickys Join Date: Feb 2001 Posts: 1,532	Bumping the Idle As some of you may know, I've had my GT in and out of the same, piece of **** machine shop for months now. Well, she went in for the last time a few weeks ago Anyways... My problem is, they set the idle so low that it stalls out when I'm sitting at lights. Its sitting around 600 now, and putts out whenever I'm sitting for more than 20-30 seconds. Does anyone know how I can temporarily bump the idle up? I don't have the cash right now to take it in and see what's really going on, but I've watched the mulleted monkey at the shop fiddle around the throttle body before to tamper with the idle...just don't know WTF he was doing?! Any suggestions??? Thanks again, Belle

05-15-2002, 02:28 AM	#2
Mach 1 Registered Member Join Date: May 1999 Location: Georgia Posts: 3,866	Turn up the idle stop screw on the throttle body. Will take you a total of about 15 seconds. __________________ 2002 GT 1993 GT (SOLD) '93 Mustang GT RHC member #142

05-15-2002, 12:24 PM	#4
andy669 Registered Member Join Date: Jan 2001 Location: Moline Il Posts: 901	Turning the idle screw up will only raise the idle temporarily. When you shut the car off and restart it, it will be down again. Adjusting the TPS is not that easy on the SN95's. The TPS screws are halfway hidden behind the IAC. Furthermore, they are almost non adjustable. They have metal bushings in the mounting holes which makes turning them almost non-existant. Does the car act any different whether it is cold or hot? I would check for a properly functioning EGR, and vacuum leaks. Does the idle change if you unplug the IAC? If all else fails, just find another shop that has an OBD I scanner. Anyone with experience should be able to find the problem that way. It shouldnt cost more than $60 to have someone scan it. If thats too much, maybe you could sweet talk them a 'lil.... hehehe andy __________________ 88 coupe 91 LX NMRA Pure Street 5120

05-15-2002, 12:39 PM	#5
LX XLR8R Dirk Diggler Join Date: Feb 1999 Location: SLOATSBURG, NY Posts: 1,931	there is a special procedure that ya got to follow when setting the idle..i dont rember it cuz its been 4 years sence i had a IAB on my car!..just unplug the stupid thing and set the screw where you want it __________________ 95 undecided cubes, AFR 185s,undecided cam, undecided intake, and a 150 hit 89 "turbonotch" 2.3T You might want to hold on..i saw this on a cartoon once

05-15-2002, 06:13 PM	#8
andy669 Registered Member Join Date: Jan 2001 Location: Moline Il Posts: 901	Mach Whenever I've tried this on my 94 the idle has always came back down. I just figured it was the computer compensating. But maybe there was something else going on that I wasnt aware of too. No, Belle I wasnt referring to the screw maunally resetting itself! Geez, do I sound that dumb? ....... Wait, dont answer that! andy __________________ 88 coupe 91 LX NMRA Pure Street 5120

05-15-2002, 07:17 AM	#3
cyberstang5.0 347ci of HORSE POWER!!! Join Date: Jul 2001 Location: Houston, TX Posts: 1,416	That "mulleted monkey" was probably adjusting the TPS (throtle position sensor). There are 2 screws that hold it on the TB. Just take a screw driver and unscrew them just a little bit (enough to move it) and trun the sensor left of right until the car idle's were you want it to. That might help ya out. Also, try unplugging the Idle air bypass sensor (it's that thing that is mounted at an angle on the TB). I did it to my car when I was having idling problems and it worked. Keep in mind, it's just a temporary fix. Hope this helps. You can always give your car to me I'll fix it

05-15-2002, 05:15 PM	#7
Mustangbelle306 Yay for Chickys Join Date: Feb 2001 Posts: 1,532	Thanks for the advice everyone, I set the screw eariler (no sweet talking necessary ) this morning with some help from Cyberstang, and I've never heard of a screw manually resetting itself on shutdown Not sure what you were talking bout... Car's running MUCH better, for now at least! Makes me feel better about finding out that the AC compressor is shot

05-15-2002, 07:30 PM	#9
Green9550 Resident Redneck Join Date: Jan 2002 Location: Cecil County, MD Posts: 165	I have to say, andy669 is right about the idle fixing itself. Kind of odd. I fixed it by setting my idle at about 1100. It works perfect now. I'm glad you figured your problem out belle. Take care. -Billy __________________ 95' GT: 306, XL Ross Pistons, Ultra Lite H-beam Rods, Forged Scat Crank, 28oz Romac, 28oz JW flexplate, FTI ported RPM II intake, FTI ported AFR 165's, FTI custom cam, 75mm BBK Throttle body, 80mm Pro-M, 4800 PI stall, PA Super Comp AODE, Strange 33 spline race axles, Strange ultra lite spool, Motive lite 4.30's, Strange rear race brakes, Mega bite seniors, double adjustable uppers w/spherical bushings, Racecraft anti-roll bar, LPW rear end girdle, Metco d/s loop, A9L conversion, AFM PMS

05-16-2002, 04:26 PM	#10
mysweetlx Registered Member Join Date: Apr 2002 Location: New York Posts: 248	Where should the idle be set at....800? 900? 1000? Is there a performance benefit to the rpm it's set at or is it a personal preference thing? __________________ Damn this thing's fast!

05-16-2002, 04:41 PM	#11
Mr 5 0 Conservative Individualist Join Date: May 1997 Location: Wherever I need to be Posts: 7,487	Idle RPM Where should the idle be set at....800? 900? 1000? Is there a performance benefit to the rpm it's set at or is it a personal preference thing? - mysweetlx: An idle RPM of 800 is fine, 900 is O.K. too but anything more wastes gas with no performance benefit at all. Yeah, it's really a personal preference thing.

05-16-2002, 05:41 PM	#12
Green9550 Resident Redneck Join Date: Jan 2002 Location: Cecil County, MD Posts: 165	Yeah, Mr 5 0 is right. An Idle of 800-850 would be ideal. I have such a high idle because that is the only way my car will stay running. I need to get a chip, that will happen June 7th. Then I'm hoping for an idle of about 850. Take care. -Billy __________________ 95' GT: 306, XL Ross Pistons, Ultra Lite H-beam Rods, Forged Scat Crank, 28oz Romac, 28oz JW flexplate, FTI ported RPM II intake, FTI ported AFR 165's, FTI custom cam, 75mm BBK Throttle body, 80mm Pro-M, 4800 PI stall, PA Super Comp AODE, Strange 33 spline race axles, Strange ultra lite spool, Motive lite 4.30's, Strange rear race brakes, Mega bite seniors, double adjustable uppers w/spherical bushings, Racecraft anti-roll bar, LPW rear end girdle, Metco d/s loop, A9L conversion, AFM PMS

05-19-2002, 07:02 PM	#14
Mach 1 Registered Member Join Date: May 1999 Location: Georgia Posts: 3,866	I guess the compter could compensate to a point, but once you turn that screw far enough, the idle will stay up. __________________ 2002 GT 1993 GT (SOLD) '93 Mustang GT RHC member #142

05-19-2002, 07:53 PM	#15
Mr 5 0 Conservative Individualist Join Date: May 1997 Location: Wherever I need to be Posts: 7,487	Idle To whom it may concern: Set the idle screw by loosening the screw until you can fit a .010" feeler gauge between the stop plate and the end of the screw. Tighten the screw until the feeler gauge comes out with some resistance. Tighten the idle screw 1 1/2 turns more. Check your TPS to make sure it's about .95-.98v. If it checks out, reset the computer. Usually, just driving the car 10 miles or more will reset the ECM.

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