Rough Idle

dcrusupra · 08-19-2005, 07:52 PM

As of right now, my 87 idles at about 600rpm. It should be 800. My idle rpm varies from about 550-1000. Is there a way i can lock it in to 800? Engine is stock except for a new intake.

ddmcse · 08-20-2005, 10:29 AM

your idle speed control valve could be shot
is this a turbo or N/A?
i am assuming it's a n/a because of the idle rpm of 800 you quoted

dcrusupra · 08-20-2005, 04:55 PM

Yea its an N/A. It only does this for the first startup of the day. After I drive it around for a little, it stays around 800-900rpm.

Poodles · 08-20-2005, 11:05 PM

I dunno if it will help an N/A, but I was having problems on my turbo model and it was a vacuum leak, changed the vacuum lines and it idles prefect now.

joel w · 08-23-2005, 04:38 AM

check the contiuity of the throttle position sensor, should have cont when fully closed. its the bottom 2 of the 4 terminals to check. if no cont then loosen the screws and adjust it to where there is continuity. i dont know why but i have had to do this twice to my car. impossable to time it unless the tps is closed. and it idles rough and will die sometimes if i let off gas to fast. try vac lines first of course.

Troyota · 08-23-2005, 01:48 PM

It could be the idle up sensor, that races the engine when it's cold...mine did this, it would also stall when stopped at traffic lights with the A/C running because the idle wouldn't increase w/ it on.

SupraDave · 08-23-2005, 07:19 PM

[QUOTE]check the contiuity of the throttle position sensor, should have cont when fully closed. its the bottom 2 of the 4 terminals to check. if no cont then loosen the screws and adjust it to where there is continuity. i dont know why but i have had to do this twice to my car. impossable to time it unless the tps is closed. and it idles rough and will die sometimes if i let off gas to fast. try vac lines first of course.

Be careful when checking the TPS. Look to see if the sensor connector faces the passenger side or drivers side. If your car is like my 86.5 N/A then the connector is on the driver side and the check terminals are the top two.

You can see what I'm talking about by viewing the attached link.

http://www.supra.co.nz/87tsrm/EFI/efi102.htm

joel w · 08-24-2005, 01:12 AM

good call, mine faces the passenger side. i think its IDL and E2 terminals

08-19-2005, 07:52 PM	#1
dcrusupra 500whp yet? Join Date: Aug 2005 Location: Plantation, Fl. Posts: 1,052	As of right now, my 87 idles at about 600rpm. It should be 800. My idle rpm varies from about 550-1000. Is there a way i can lock it in to 800? Engine is stock except for a new intake. __________________ New Rebuild My CarDomain

08-20-2005, 10:29 AM	#2
ddmcse 500whp yet? Join Date: Jun 2005 Location: CT U.S.A. Posts: 966	your idle speed control valve could be shot is this a turbo or N/A? i am assuming it's a n/a because of the idle rpm of 800 you quoted __________________ 300+ RW HP Dyno run, jdm,mod turbo,3"exh,electfan,greddyboost Blown HeadGasket info My Supra KiXGaS

08-20-2005, 04:55 PM	#3
dcrusupra 500whp yet? Join Date: Aug 2005 Location: Plantation, Fl. Posts: 1,052	Yea its an N/A. It only does this for the first startup of the day. After I drive it around for a little, it stays around 800-900rpm. __________________ New Rebuild My CarDomain

08-23-2005, 01:48 PM	#6
Troyota 3" Exhaust Join Date: Jul 2005 Location: Roswell, NM Posts: 73	It could be the idle up sensor, that races the engine when it's cold...mine did this, it would also stall when stopped at traffic lights with the A/C running because the idle wouldn't increase w/ it on. __________________ 1987 N/A MA70 Supra <--1JZ swap in progress 1986 AE86 GT-S Hatchback 2002 DC5 RSX Type S

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08-20-2005, 11:05 PM	#4
Poodles 12psi boost Join Date: Jul 2005 Posts: 348	I dunno if it will help an N/A, but I was having problems on my turbo model and it was a vacuum leak, changed the vacuum lines and it idles prefect now.

08-23-2005, 04:38 AM	#5
joel w Lexus & 550's Join Date: Aug 2005 Location: In the shadows Posts: 506	check the contiuity of the throttle position sensor, should have cont when fully closed. its the bottom 2 of the 4 terminals to check. if no cont then loosen the screws and adjust it to where there is continuity. i dont know why but i have had to do this twice to my car. impossable to time it unless the tps is closed. and it idles rough and will die sometimes if i let off gas to fast. try vac lines first of course.

08-23-2005, 07:19 PM	#7
SupraDave Stock Join Date: Jul 2005 Posts: 11	[QUOTE]check the contiuity of the throttle position sensor, should have cont when fully closed. its the bottom 2 of the 4 terminals to check. if no cont then loosen the screws and adjust it to where there is continuity. i dont know why but i have had to do this twice to my car. impossable to time it unless the tps is closed. and it idles rough and will die sometimes if i let off gas to fast. try vac lines first of course. Be careful when checking the TPS. Look to see if the sensor connector faces the passenger side or drivers side. If your car is like my 86.5 N/A then the connector is on the driver side and the check terminals are the top two. You can see what I'm talking about by viewing the attached link. http://www.supra.co.nz/87tsrm/EFI/efi102.htm

08-24-2005, 01:12 AM	#8
joel w Lexus & 550's Join Date: Aug 2005 Location: In the shadows Posts: 506	good call, mine faces the passenger side. i think its IDL and E2 terminals