88 Supra idle

soccerwolf · 07-20-2006, 01:21 PM

I have an 88 Supra, non-turbo. Bought it 4 months ago. Previous owner replaced engine (approx 25k miles on new engine). Car runs & drives great, but... Lately the idle speed is all over the place. Sometimes when I put the clutch in, it idles at something less than 1000 rpm, which seems normal. Sometimes it idles at about 1500, sometimes 2000. This morning it was at slightly over 2000. I live about 2 miles from work and it may be different when I start it and when I stop. Any suggestions?

mrnickleye · 07-21-2006, 12:36 AM

check the TSRM for some help.
http://www.cygnusx1.net/supra/library/TSRM/

You will just have to start testing things like the TPS, AFM, ISC valve.

First make sure you don't have any vacuum leaks, and the plugs and wires, cap and rotor are good.

scruffboy · 07-28-2006, 06:40 PM

This may sound stupid, but I thought I had an idling problem when all it was was the floor mat had shifted up ontop of the accelerator. Yes, I felt like an A-hole.

Scruff

lethalwithasupra · 07-29-2006, 09:48 AM

... does it idle high at first for maybe 10 or 15 mins and then go down to a normal idle after it warms up ? Cos it could be the cold-start injector doing its normal job

soccerwolf · 03-12-2010, 01:08 AM

Completely forgot about my original post here. I eventually traced the problem to the idle speed screw. It was loose and the engine vibration caused it to rotate in or out. I could adjust it to a decent, low idle then drive the car for a few miles and the idle would be back to 2000+. Solved the problem by removing the screw and reinstalling with a stiff spring under the head. The spring tension eliminated the vibration-induced self-adjustment.

07-20-2006, 01:21 PM	#1
soccerwolf Stock Join Date: Jul 2006 Location: South Carolina Posts: 3	88 Supra idle I have an 88 Supra, non-turbo. Bought it 4 months ago. Previous owner replaced engine (approx 25k miles on new engine). Car runs & drives great, but... Lately the idle speed is all over the place. Sometimes when I put the clutch in, it idles at something less than 1000 rpm, which seems normal. Sometimes it idles at about 1500, sometimes 2000. This morning it was at slightly over 2000. I live about 2 miles from work and it may be different when I start it and when I stop. Any suggestions?

07-21-2006, 12:36 AM	#2
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	check the TSRM for some help. http://www.cygnusx1.net/supra/library/TSRM/ You will just have to start testing things like the TPS, AFM, ISC valve. First make sure you don't have any vacuum leaks, and the plugs and wires, cap and rotor are good. __________________ Had a Red 1989 N/A. Automatic. Sports Pkg. w/wing. TEMS, and some nice MODS. Sold to a friend 10/08/08.

07-28-2006, 06:40 PM	#3
scruffboy walbro fp Join Date: Sep 2005 Location: Kearny, New Jersey, USA Posts: 427	Kinda dumb This may sound stupid, but I thought I had an idling problem when all it was was the floor mat had shifted up ontop of the accelerator. Yes, I felt like an A-hole. Scruff

07-29-2006, 09:48 AM	#4
lethalwithasupra 3" Exhaust Join Date: Sep 2005 Location: south cantebury Posts: 112	Not trying to sound like an arsehole, but unsure how else to phrase it ... does it idle high at first for maybe 10 or 15 mins and then go down to a normal idle after it warms up ? Cos it could be the cold-start injector doing its normal job __________________ So I bought this old Honda bike, an NSR250. Bit of a street racer, I guess. I'm told they're fast. Delivering it home with a friend driving the Supra for the first time. I drop gears and make a scream from the twin pipes flowing down this pony's flanks and it takes off like it's tail's on fire. I look back when the Honda gets to its tap-out and the Supra's only two lengths behind. No one I've let ride my bike has told me its slow, they've all loved the thing. That car is a good thing indeed.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Questions about MKIV Supra	ukno0003	MKIV Supra	5	11-06-2008 10:53 AM
Dream Offer	Karma_Supra	MKIV Supra	22	10-17-2007 03:04 PM
1987 Toyota Supra Idle	spycialost9999	Non-Generation Specific Questions	3	06-14-2006 06:33 PM
Idle problem 1988 Supra non turbo	jimwww	Non-Generation Specific Questions	3	01-24-2006 03:50 PM
HELP!!!! '87 Supra idle problem	Morpho	MKIII Supra	0	10-03-2005 02:40 PM

03-12-2010, 01:08 AM	#5
soccerwolf Stock Join Date: Jul 2006 Location: South Carolina Posts: 3	Completely forgot about my original post here. I eventually traced the problem to the idle speed screw. It was loose and the engine vibration caused it to rotate in or out. I could adjust it to a decent, low idle then drive the car for a few miles and the idle would be back to 2000+. Solved the problem by removing the screw and reinstalling with a stiff spring under the head. The spring tension eliminated the vibration-induced self-adjustment.