idle problems

BLOCKER · 05-22-2003, 12:42 AM

My mustang has the following mods:
cobra intake
gt 40 heads
hypertech superchip
mac underdrive pullies
full 2 1/2" pipes
headers

Since I replaced the intake and heads (did bearings at the same time) The car does not want to idle at stop light, it runs great when in motion, no problems..... but when left to idle it does not want to... any sugestions

The car is still a speed density car and is not cammed.

Bad89stang · 05-22-2003, 05:17 AM

you need to be more specific.

it doesn't idle in what way?

does it die? does it surge? does it idle rough? does it idle too low/high.

expand a little and the problem will be more easily resolved.

tmoss · 05-22-2003, 07:29 AM

First things to do are to remove the Idle Air Control (IAC - on the side of the throttle body) and clean it out REALLY good. Make sure there is NO gunk left in it and the plunger is nice and free. Then reset/check your idle adjustment.

Then take apart the ten-pin connectors (black and white connectors hanging on the back of the upper intake) and clean the contact surfaces real good and spread the male connector a little for better contact.

Then remove your EGR valve and be sure the seat is clean enough for the valve to close. If not clean it up too.

Then check to be sure your Throttle Position Switch (TPS) is at or below .97vdc at idle.

BLOCKER · 05-22-2003, 01:59 PM

Thanks I will give it a try.....

By not Idling I mean..... it will start up an run just fine, but it will stall out after it has been driving ie// at a stop light

Bad89stang · 05-22-2003, 03:50 PM

In that case it is your IAC motor or EGR valve

PKRWUD · 05-24-2003, 12:51 PM

I doubt it's your IAC because once the vehicle is warmed up, it has very little effect. It could be a sticking EGR valve. Try disconnecting and plugging the vacuum to the EGR when it's cold, and see if the problem goes away. If it does, replace the EGR. If it doesn't, try removing the ECM chip, and see if that makes a difference. My money is on the EGR.

Take care,
~Chris

05-22-2003, 12:42 AM	#1
BLOCKER Registered Member Join Date: Mar 1999 Location: EDMONTON, Alberta, Canada Posts: 232	idle problems My mustang has the following mods: cobra intake gt 40 heads hypertech superchip mac underdrive pullies full 2 1/2" pipes headers Since I replaced the intake and heads (did bearings at the same time) The car does not want to idle at stop light, it runs great when in motion, no problems..... but when left to idle it does not want to... any sugestions The car is still a speed density car and is not cammed. __________________ -1988 MUSTANG COBRA GT (Canadian...eh!) -1987 Mustang LX coupe (2.3L) -1978 Harley Davidson FLH -2008 Harley Davidson Nightster 1200 -2008 Harley Davidson Night Rod Special -1997 Jaguar XK8 Convertable

05-22-2003, 05:17 AM	#2
Bad89stang Registered Member Join Date: Aug 2001 Location: Ft. Worth, TX Posts: 456	you need to be more specific. it doesn't idle in what way? does it die? does it surge? does it idle rough? does it idle too low/high. expand a little and the problem will be more easily resolved. __________________ You're gonna need your seatbelt

05-22-2003, 07:29 AM	#3
tmoss Registered Member Join Date: Mar 2003 Location: Saint Louis, MO Posts: 634	First things to do are to remove the Idle Air Control (IAC - on the side of the throttle body) and clean it out REALLY good. Make sure there is NO gunk left in it and the plunger is nice and free. Then reset/check your idle adjustment. Then take apart the ten-pin connectors (black and white connectors hanging on the back of the upper intake) and clean the contact surfaces real good and spread the male connector a little for better contact. Then remove your EGR valve and be sure the seat is clean enough for the valve to close. If not clean it up too. Then check to be sure your Throttle Position Switch (TPS) is at or below .97vdc at idle. __________________ Tom (Torque) Moss 88Gt 5spd Vert, FLowmaster Catbacks, stock cam advanced 4° @ 108.5° ICL, NMRA prepped GT40P heads 1.85/1.55 valves and 1.7 rockers, MAC P headers Jet-Hot coated, 97 Exlporer intake (ported lower), TB and injectors. 277RWHP/330RWTQ (SAE). http://www.fastlanecars.com/

05-22-2003, 03:50 PM	#5
Bad89stang Registered Member Join Date: Aug 2001 Location: Ft. Worth, TX Posts: 456	In that case it is your IAC motor or EGR valve __________________ You're gonna need your seatbelt

05-24-2003, 12:51 PM	#6
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	I doubt it's your IAC because once the vehicle is warmed up, it has very little effect. It could be a sticking EGR valve. Try disconnecting and plugging the vacuum to the EGR when it's cold, and see if the problem goes away. If it does, replace the EGR. If it doesn't, try removing the ECM chip, and see if that makes a difference. My money is on the EGR. Take care, ~Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

05-22-2003, 01:59 PM	#4
BLOCKER Registered Member Join Date: Mar 1999 Location: EDMONTON, Alberta, Canada Posts: 232	Thanks I will give it a try..... By not Idling I mean..... it will start up an run just fine, but it will stall out after it has been driving ie// at a stop light

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