car acting up at idle

NotchJohnson · 02-13-2002, 03:41 PM

My car just started acting up at idle over the last few days. At cruising speed the car runs fine, but as soon as it stops moving, especially in gear, the idle surges from 500-700rpm.It doesnt stall out in neutral, but it does in drive when it isnt rolling, I have also noticed some surging in overdrive when the rps drop to around 1000. Has this ever happened to any of you guys?What could this be? Any help would be appreciated, Thanks -John

David Fulford · 02-13-2002, 07:43 PM

Sounds like a vacuum leak somewhere. Could be a million things but start with simple things like checking your vacume hoses.

gtsr515 · 02-14-2002, 07:48 PM

Considering your stock, it's most likely a sensor is bad or out of range, run an EEC test if you have the means. Start by cleaning your IAB and checking TPS voltage, hows the fuel pump, any vacuum leaks?

PKRWUD · 02-15-2002, 05:34 AM

Could be a sensor, and a KOEO and KOER self test are a great idea, but I think it sounds more like a vacuum leak. You should run the self tests, and check for vacuum leaks.

Take care,
-Chris

NotchJohnson · 02-15-2002, 10:57 AM

Thanks alot guys, I am now noticing that at cruising speed, 45-55 the car has just cut out of a split second a few times. What could be causing this? Its starting to piss me off, I dont have class today so im gonna look at it. Thanks for the help, John

Hozer 88GTConv · 02-15-2002, 03:20 PM

I have the same problem lately, notch. Do you have your EGR removed? I have mine blanked off and the plunger zip tied fully depressed. I have noticed a subtle "miss" sometimes when I gun it, and sometimes it is readily apparent when the motor is cold.
I have swapped plugs twice, checked tps, changed wires, new coil, etc...no luck.
Swapped a old tps and IAC back in to see if it changed anything and it still does it.
Next step is a reinstall of the egr plate to see if that cures it.

NotchJohnson · 02-16-2002, 12:35 PM

I do have all the smog crap taken out and my egr is not hooked up. It has been that way for about a month and half now with no problems but all of a sudden it started acting up. Did yours start doing that right away after you disabled the egr?

Hozer 88GTConv · 02-16-2002, 07:41 PM

Notch, I have had it disconnected for six months and the idle has been squirrely pretty much since then. Occassionaly, an adjustment would seem to work (TPS, or IAC clean) but it would return to erratic after a while.
I have decided to hook the EGR plate back on and reattach the vacuum line, because I have the supply vacuum line NOT plugged. So maybe I was dumb from the get go not doing that, but I'm doing it tomorrow in the morning first thing and I will let you know.

02-13-2002, 03:41 PM	#1
NotchJohnson Registered Member Join Date: Oct 2001 Location: Florida Keys Posts: 593	car acting up at idle My car just started acting up at idle over the last few days. At cruising speed the car runs fine, but as soon as it stops moving, especially in gear, the idle surges from 500-700rpm.It doesnt stall out in neutral, but it does in drive when it isnt rolling, I have also noticed some surging in overdrive when the rps drop to around 1000. Has this ever happened to any of you guys?What could this be? Any help would be appreciated, Thanks -John __________________ 89 notch-finally not stock!! ported gt40's, ported cobra intake, 65mm tb, 75mm maf, mac cai, lt's,prochamber, fms 1.6 rr, 125 shot.

02-13-2002, 07:43 PM	#2
David Fulford Registered Member Join Date: Oct 2000 Location: Charlotte NC Posts: 193	Sounds like a vacuum leak somewhere. Could be a million things but start with simple things like checking your vacume hoses. __________________ 1969 fast back; yellow; weld wheels; 302 roller with GT-40 heads; 3:55 gears; 5spd T-5; MSD 6AL; E-303; flows; Hedman headers; Holley 600;Weiand Accelerator;1.6 rockers

02-14-2002, 07:48 PM	#3
gtsr515 Registered Member Join Date: Nov 2001 Location: Sunny, Hot, Sebring, Florida Posts: 725	Considering your stock, it's most likely a sensor is bad or out of range, run an EEC test if you have the means. Start by cleaning your IAB and checking TPS voltage, hows the fuel pump, any vacuum leaks? __________________ Remember...2nd place is 1st place for losers!

02-15-2002, 05:34 AM	#4
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Could be a sensor, and a KOEO and KOER self test are a great idea, but I think it sounds more like a vacuum leak. You should run the self tests, and check for vacuum leaks. Take care, -Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

02-15-2002, 10:57 AM	#5
NotchJohnson Registered Member Join Date: Oct 2001 Location: Florida Keys Posts: 593	Thanks alot guys, I am now noticing that at cruising speed, 45-55 the car has just cut out of a split second a few times. What could be causing this? Its starting to piss me off, I dont have class today so im gonna look at it. Thanks for the help, John __________________ 89 notch-finally not stock!! ported gt40's, ported cobra intake, 65mm tb, 75mm maf, mac cai, lt's,prochamber, fms 1.6 rr, 125 shot.

02-15-2002, 03:20 PM	#6
Hozer 88GTConv Registered Member Join Date: Feb 2002 Location: Jacksonville, FL Posts: 706	Similar problem... I have the same problem lately, notch. Do you have your EGR removed? I have mine blanked off and the plunger zip tied fully depressed. I have noticed a subtle "miss" sometimes when I gun it, and sometimes it is readily apparent when the motor is cold. I have swapped plugs twice, checked tps, changed wires, new coil, etc...no luck. Swapped a old tps and IAC back in to see if it changed anything and it still does it. Next step is a reinstall of the egr plate to see if that cures it. __________________ 1988 GT Convertible 331 10:1 TW heads, GT-40 intake, MSD, TRW flattops, B Cam w/ 1.7's, MAC exhaust, 24's, 70 TB, 76 MAF, 3.73's, Pro 5.0, Koni's, Anderson PMS, Wideband 02, yatta, yatta... One week with new motor, two speeding tickets...joy

02-16-2002, 12:35 PM	#7
NotchJohnson Registered Member Join Date: Oct 2001 Location: Florida Keys Posts: 593	I do have all the smog crap taken out and my egr is not hooked up. It has been that way for about a month and half now with no problems but all of a sudden it started acting up. Did yours start doing that right away after you disabled the egr? __________________ 89 notch-finally not stock!! ported gt40's, ported cobra intake, 65mm tb, 75mm maf, mac cai, lt's,prochamber, fms 1.6 rr, 125 shot.

02-16-2002, 07:41 PM	#8
Hozer 88GTConv Registered Member Join Date: Feb 2002 Location: Jacksonville, FL Posts: 706	EGR... Notch, I have had it disconnected for six months and the idle has been squirrely pretty much since then. Occassionaly, an adjustment would seem to work (TPS, or IAC clean) but it would return to erratic after a while. I have decided to hook the EGR plate back on and reattach the vacuum line, because I have the supply vacuum line NOT plugged. So maybe I was dumb from the get go not doing that, but I'm doing it tomorrow in the morning first thing and I will let you know. __________________ 1988 GT Convertible 331 10:1 TW heads, GT-40 intake, MSD, TRW flattops, B Cam w/ 1.7's, MAC exhaust, 24's, 70 TB, 76 MAF, 3.73's, Pro 5.0, Koni's, Anderson PMS, Wideband 02, yatta, yatta... One week with new motor, two speeding tickets...joy

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