anyone else ever had this problem?

87fox2e · 06-03-2008, 11:48 PM

alright i got a brand new air charge temp sensor the other day. Installed it due to the fact that i didnt have one installed in the first place (long story). Anyways i plug it in and my idle goes crazy. It will idle at like 2,000rpm and stay there, then when i shift it will idle even higher between shifts. Its ridiculous, and makes no sense to me. without the sensor my car will idle down and up and so on just like if i had a bad IAC valve, but with it the idle is even worse. any suggestions this is my last code, and my car will finally run normal and the mods can begin. thanks for any input.

my car is a 87 5.0 5spd still speed density

marunos · 06-04-2008, 03:58 PM

Hey dude, i can only think of throttle! Maybe you need to adjust the throttle valve (butterfly plate) you can increase the thottle by screwing the valve in your direction. I think you will see ur car goes idle when it's cold.. but with giving more throttle then i think it should be fine.. just try it and see if it works. increase the throttle untill you see the RPM is at around 1500 or so.. and test drive the car.
Marwan

seco · 06-04-2008, 10:28 PM

make sure no shorts are found in the wiring harness that the temp sensor plugs into.
+1 on cleaning your idle air control with some choke cleaner. also try playing with idle set screw in your idle air control.

**Sonic Blue 85** · 06-04-2008, 11:15 PM

Your throttle may be open too far, check the TP voltage it should be less than 1.00 volts. You may also have a vacuum leak. I would bet you have at least two problems.

87fox2e · 06-05-2008, 03:39 AM

alright ill try it out. that was my last trouble code, and when i plug it in i lose the code, but seem to gain more problems.

87fox2e · 06-10-2008, 09:36 AM

alright i got another new air charge temp sensor, i put a new TPS on and i cleaned the IAC. I got nothing. my idle is stuck at around 1200RPM now, when i turn on the a/c it goes down to about 900-1000RPM. Call me an idiot, but im not sure what adjusting screw yall are talking about. Can you give me little more info or pics even maybe. Anyways this really sucks so any help and as quick as possible would be appreciated. Thanks

87fox2e · 06-10-2008, 09:47 AM

oh ya, and if i drive with the TPS completely unplugged it pretty much runs normal (that includes the new onw).

thatdavidkid · 06-10-2008, 10:08 AM

so with everything installed, it runs fine just idles high? you have an idle adjustment screw... turn it down, chances are someone cranked up the idle to keep it running due to the lack of that sensor...

87fox2e · 06-10-2008, 10:37 AM

ok sounds good. is the adjustment screw the one under the TPS? forgive my ignorance im still learning alot.

thatdavidkid · 06-10-2008, 10:50 AM

Quote:

Originally Posted by 87fox2e

ok sounds good. is the adjustment screw the one under the TPS? forgive my ignorance im still learning alot.

your throttle cable atatches to a half moon shaped thing... when you pull it, and let it go, there is a screw that stops it at the end... that is the idle control screw...

87fox2e · 06-10-2008, 11:31 AM

awesome i know what you are talking about now. ill try it out.

87fox2e · 06-10-2008, 02:06 PM

alright cool i adjusted the screw and the idles not so high anymore. but it still has the issue of staying reved high up when i shift gears, and if i rev it at idle it it takes awhile for the idle to come back down to normal. i dont believe i have any vaccum leaks though. i guess i still gotta check for shorts though.

thatdavidkid · 06-10-2008, 02:32 PM

still sounds like a bad sensor of some sort or a vacuum leak...

seco · 06-10-2008, 05:08 PM

when you removed the idle air control from the tbody to clean it, was the idle air control gasket in good condition?

87fox2e · 06-11-2008, 12:33 AM

ya the gasket is fairly new the IAC was replaced not to long ago along with the gasket. the variable idle is gone now, its just the high rev between shifts i got going on now. but its only if i have the air charge temp. sensor plugged in(which is also brand new).

thatdavidkid · 06-11-2008, 10:54 AM

i would maybe check for high resistance or something in that circuit... something seems odd...

**Sonic Blue 85** · 06-11-2008, 07:12 PM

You should check the TP voltage or have it checked, it needs to be under 1.00 volts. I useualy set them no higher than .95v. You very possibly have a vacuum leak/ Do you have stock injectors and or a adjustable fuel pressure regulator. One final thing is how old are the O2 sensors?

CraZy6 · 06-12-2008, 12:17 AM

Try this:

Base Idle Reset Procedure

1. Clean TB with carb cleaner and nylon brush (toothbrush size). Engine off, fully open TB blade and spray/brush TB until all gunk and oil residue is cleaned.

2. Allow to dry, or close TB blade and start engine until it clears all carb cleaner fumes/liquid.

3. Let engine idle...if it doesn't, increase idle speed via TB stop screw until engine stays idling on its own.

4. Disconnect IAC valve, if engine dies repeat 3 with IAC disconnected.

5. Set idle speed to the lowest setting possible between 650-850 rpms with IAC disconnected. It is key to use the lowest possible to prevent idle surge, rolling, etc once the IAC is connected as follows.

6. Turn engine off, and reconnect IAC

7. With Ign On Eng Off, check TPS voltage output....if it's between .8vdc - 1.0vdc, it's OK. This voltage check should be done between the Green and Black wires at the TPS side connector as shown in the pic below (FYI: Green = TPS Signal, Black = SIGRTN, and Orange = VREF)....(-) terminal of the DVOM on the Black wire and (+) terminal on the Green wire.

8. Disconnect battery (-) for 3-4 minutes.

9. Reconnect battery, start engine, allow it to idle for 2-4 minutes to confirm setup,

10. If idle speed falls too low or stalls, increase idle speed via the TB set screw a little at a time.

11. Turn engine off for 20 seconds, re-start engine and repeat 9 - 11 if required.

12. Reconfirm TPS output is within the .8vdc - 1.0vdc range optimum range.

NOTES:

1. No need to reset ECM KAM (reset computer), the TPS minimum value used for idle control, is reset automatically by the EEC-IV every time the ign is cycled on-off for 20 seconds-on.

2. If the TPS output is within 6vdc - 1.1vdc, it's still acceptable, since no TPS failure codes will be generated, and it falls within the EEC-IV .5vdc - 1.19vdc working range.

13. Allow a 10-20 minute "relearning" period under normal driving conditions (drive cycle).....you're done!

87fox2e · 06-12-2008, 12:53 AM

awesome post ill try that out tomorrow. thanks

CraZy6 · 06-13-2008, 12:26 PM

Quote:

Originally Posted by 87fox2e

awesome post ill try that out tomorrow. thanks

It took my car about a full a day to relearn, due to my X-cam.

06-03-2008, 11:48 PM	#1
87fox2e Registered User Join Date: Mar 2008 Location: San Antonio Posts: 65 Trader Rating: (0)	anyone else ever had this problem? alright i got a brand new air charge temp sensor the other day. Installed it due to the fact that i didnt have one installed in the first place (long story). Anyways i plug it in and my idle goes crazy. It will idle at like 2,000rpm and stay there, then when i shift it will idle even higher between shifts. Its ridiculous, and makes no sense to me. without the sensor my car will idle down and up and so on just like if i had a bad IAC valve, but with it the idle is even worse. any suggestions this is my last code, and my car will finally run normal and the mods can begin. thanks for any input. my car is a 87 5.0 5spd still speed density

06-04-2008, 11:15 PM	#4
Sonic Blue 85 LSS Sponsor Join Date: Dec 2007 Location: New Braunfels Posts: 396 Trader Rating: (1)	Your throttle may be open too far, check the TP voltage it should be less than 1.00 volts. You may also have a vacuum leak. I would bet you have at least two problems. __________________ My car is an '85 sonic blue coupe with 302 bored and stroked to 364, Ported Twisted Wedge heads and a BXR intake, A9M ECM with a Tweecer, C4 with trans brake, Hoosier 275/60/15 drag radials, no power adders. The car is still street driven, with a best of 10.21 at 131 mph with a 1.51 60' spinning lightly. With this combo it made a best of 460 hp and 410 lbs of torque at the wheels.

06-10-2008, 09:36 AM	#6
87fox2e Registered User Join Date: Mar 2008 Location: San Antonio Posts: 65 Trader Rating: (0)	alright i got another new air charge temp sensor, i put a new TPS on and i cleaned the IAC. I got nothing. my idle is stuck at around 1200RPM now, when i turn on the a/c it goes down to about 900-1000RPM. Call me an idiot, but im not sure what adjusting screw yall are talking about. Can you give me little more info or pics even maybe. Anyways this really sucks so any help and as quick as possible would be appreciated. Thanks __________________ 87 GT 5spd. JBA cold air intake, flows, and king cobra clutch...more to come, hopefully soon.

06-10-2008, 09:47 AM	#7
87fox2e Registered User Join Date: Mar 2008 Location: San Antonio Posts: 65 Trader Rating: (0)	oh ya, and if i drive with the TPS completely unplugged it pretty much runs normal (that includes the new onw). __________________ 87 GT 5spd. JBA cold air intake, flows, and king cobra clutch...more to come, hopefully soon.

06-10-2008, 10:08 AM	#8
thatdavidkid looks mean, workin' on the fast Join Date: Oct 2006 Location: Denton Posts: 3,903 Trader Rating: (1)	so with everything installed, it runs fine just idles high? you have an idle adjustment screw... turn it down, chances are someone cranked up the idle to keep it running due to the lack of that sensor... __________________ 1991 lx coupe t-5 swap, billit quadrant, upr firewall adjuster, steeda tri-ax, custom jb tool and fab one off subframe connectors, 8.8 w/posi and 4.10's with 5 lug axles, tubular upper control arms, southside lowers, and pbr twin piston front calipers with "snowflake" wheels

06-04-2008, 03:58 PM	#2
marunos Registered User Join Date: May 2008 Location: Oman Posts: 61 Trader Rating: (0)	Hey dude, i can only think of throttle! Maybe you need to adjust the throttle valve (butterfly plate) you can increase the thottle by screwing the valve in your direction. I think you will see ur car goes idle when it's cold.. but with giving more throttle then i think it should be fine.. just try it and see if it works. increase the throttle untill you see the RPM is at around 1500 or so.. and test drive the car. Marwan

06-04-2008, 10:28 PM	#3
seco 4 valve Join Date: Apr 2005 Posts: 946 Trader Rating: (0)	make sure no shorts are found in the wiring harness that the temp sensor plugs into. +1 on cleaning your idle air control with some choke cleaner. also try playing with idle set screw in your idle air control.

06-05-2008, 03:39 AM	#5
87fox2e Registered User Join Date: Mar 2008 Location: San Antonio Posts: 65 Trader Rating: (0)	alright ill try it out. that was my last trouble code, and when i plug it in i lose the code, but seem to gain more problems.

06-10-2008, 10:37 AM	#9
87fox2e Registered User Join Date: Mar 2008 Location: San Antonio Posts: 65 Trader Rating: (0)	ok sounds good. is the adjustment screw the one under the TPS? forgive my ignorance im still learning alot. __________________ 87 GT 5spd. JBA cold air intake, flows, and king cobra clutch...more to come, hopefully soon.

06-10-2008, 11:31 AM	#11
87fox2e Registered User Join Date: Mar 2008 Location: San Antonio Posts: 65 Trader Rating: (0)	awesome i know what you are talking about now. ill try it out. __________________ 87 GT 5spd. JBA cold air intake, flows, and king cobra clutch...more to come, hopefully soon.

06-10-2008, 02:06 PM	#12
87fox2e Registered User Join Date: Mar 2008 Location: San Antonio Posts: 65 Trader Rating: (0)	alright cool i adjusted the screw and the idles not so high anymore. but it still has the issue of staying reved high up when i shift gears, and if i rev it at idle it it takes awhile for the idle to come back down to normal. i dont believe i have any vaccum leaks though. i guess i still gotta check for shorts though. __________________ 87 GT 5spd. JBA cold air intake, flows, and king cobra clutch...more to come, hopefully soon.

06-10-2008, 02:32 PM	#13
thatdavidkid looks mean, workin' on the fast Join Date: Oct 2006 Location: Denton Posts: 3,903 Trader Rating: (1)	still sounds like a bad sensor of some sort or a vacuum leak... __________________ 1991 lx coupe t-5 swap, billit quadrant, upr firewall adjuster, steeda tri-ax, custom jb tool and fab one off subframe connectors, 8.8 w/posi and 4.10's with 5 lug axles, tubular upper control arms, southside lowers, and pbr twin piston front calipers with "snowflake" wheels

06-10-2008, 05:08 PM	#14
seco 4 valve Join Date: Apr 2005 Posts: 946 Trader Rating: (0)	when you removed the idle air control from the tbody to clean it, was the idle air control gasket in good condition?

06-11-2008, 12:33 AM	#15
87fox2e Registered User Join Date: Mar 2008 Location: San Antonio Posts: 65 Trader Rating: (0)	ya the gasket is fairly new the IAC was replaced not to long ago along with the gasket. the variable idle is gone now, its just the high rev between shifts i got going on now. but its only if i have the air charge temp. sensor plugged in(which is also brand new). __________________ 87 GT 5spd. JBA cold air intake, flows, and king cobra clutch...more to come, hopefully soon.

06-11-2008, 10:54 AM	#16
thatdavidkid looks mean, workin' on the fast Join Date: Oct 2006 Location: Denton Posts: 3,903 Trader Rating: (1)	i would maybe check for high resistance or something in that circuit... something seems odd... __________________ 1991 lx coupe t-5 swap, billit quadrant, upr firewall adjuster, steeda tri-ax, custom jb tool and fab one off subframe connectors, 8.8 w/posi and 4.10's with 5 lug axles, tubular upper control arms, southside lowers, and pbr twin piston front calipers with "snowflake" wheels

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06-11-2008, 07:12 PM	#17
Sonic Blue 85 LSS Sponsor Join Date: Dec 2007 Location: New Braunfels Posts: 396 Trader Rating: (1)	You should check the TP voltage or have it checked, it needs to be under 1.00 volts. I useualy set them no higher than .95v. You very possibly have a vacuum leak/ Do you have stock injectors and or a adjustable fuel pressure regulator. One final thing is how old are the O2 sensors? __________________ My car is an '85 sonic blue coupe with 302 bored and stroked to 364, Ported Twisted Wedge heads and a BXR intake, A9M ECM with a Tweecer, C4 with trans brake, Hoosier 275/60/15 drag radials, no power adders. The car is still street driven, with a best of 10.21 at 131 mph with a 1.51 60' spinning lightly. With this combo it made a best of 460 hp and 410 lbs of torque at the wheels.

06-12-2008, 12:17 AM	#18
CraZy6 Registered User Join Date: Jun 2003 Location: Corpus Christi,TX Posts: 836 Trader Rating: (0)	Try this: Base Idle Reset Procedure 1. Clean TB with carb cleaner and nylon brush (toothbrush size). Engine off, fully open TB blade and spray/brush TB until all gunk and oil residue is cleaned. 2. Allow to dry, or close TB blade and start engine until it clears all carb cleaner fumes/liquid. 3. Let engine idle...if it doesn't, increase idle speed via TB stop screw until engine stays idling on its own. 4. Disconnect IAC valve, if engine dies repeat 3 with IAC disconnected. 5. Set idle speed to the lowest setting possible between 650-850 rpms with IAC disconnected. It is key to use the lowest possible to prevent idle surge, rolling, etc once the IAC is connected as follows. 6. Turn engine off, and reconnect IAC 7. With Ign On Eng Off, check TPS voltage output....if it's between .8vdc - 1.0vdc, it's OK. This voltage check should be done between the Green and Black wires at the TPS side connector as shown in the pic below (FYI: Green = TPS Signal, Black = SIGRTN, and Orange = VREF)....(-) terminal of the DVOM on the Black wire and (+) terminal on the Green wire. 8. Disconnect battery (-) for 3-4 minutes. 9. Reconnect battery, start engine, allow it to idle for 2-4 minutes to confirm setup, 10. If idle speed falls too low or stalls, increase idle speed via the TB set screw a little at a time. 11. Turn engine off for 20 seconds, re-start engine and repeat 9 - 11 if required. 12. Reconfirm TPS output is within the .8vdc - 1.0vdc range optimum range. NOTES: 1. No need to reset ECM KAM (reset computer), the TPS minimum value used for idle control, is reset automatically by the EEC-IV every time the ign is cycled on-off for 20 seconds-on. 2. If the TPS output is within 6vdc - 1.1vdc, it's still acceptable, since no TPS failure codes will be generated, and it falls within the EEC-IV .5vdc - 1.19vdc working range. 13. Allow a 10-20 minute "relearning" period under normal driving conditions (drive cycle).....you're done!

06-12-2008, 12:53 AM	#19
87fox2e Registered User Join Date: Mar 2008 Location: San Antonio Posts: 65 Trader Rating: (0)	awesome post ill try that out tomorrow. thanks __________________ 87 GT 5spd. JBA cold air intake, flows, and king cobra clutch...more to come, hopefully soon.