High Idling speed 89 Celica gts - Toyota Nation Forum : Toyota Car and Truck Forums

Jman · 10-06-2003, 06:49 PM

I have an 89 celica gts, 3sge motor. when i start the car the rpm goes up to 1500 rpm, after the car totaly warms up it goes down to 1000 rpm. I can only change the rpm to 750 when i turn the idle screw..but the car vibrate alot at that speed. I check timing, with E1 and T1` jumped on check connector, timing is good 10 degrees. I changed MAF, I check the vacuum tubes. egr is ok, oh this engine came from Japan with the egr not hookek up ,so i ran the egr tube and hooked it up...but this idling probem was there before i even touch egr. Air inlet hose seems ok, changed distributor. check computer engine codes which is ok. Does anyone know what can be the problem?

Thanks
Jerry

drdma · 10-08-2003, 12:28 AM

The TCCS system doesn't need to manually set the idle speed. There is an idle screw also, but it must be closed totally, let the system regulate the idle speed. The system samples the RPM and if it is moved +-50 RPM to its desired RPM, the ECU controls the ISC valve to set up the appropriate speed.

So, chek out the input sensors for the ECU, especially the water temp. sensor and MAF (MAP? what do You have). This sensors are describing the idle speed.

Also check the ISC valve!

Refer the characteristics in the repair book.

Jman · 10-08-2003, 08:08 AM

I was thinking of changing the water temperture senors and the rest of the bscv (bimetallic contorl valves) ...around the water temp...housing.. , Are you saying the idle screw should be fully closed?... I have a MAF

Jerry

drdma · 10-08-2003, 08:26 AM

If You have idle screw on the throttle body, then close it. Don't touch the screw on the MAF.

The bimetallic switch on(in) the water hose is for the cold start injector. Don't touch it. It is for starting purposes only.

Do You have something like this?

http://www.thurzol.org.yu/~drdma/cel...parts_%205.jpg

Jman · 10-10-2003, 05:55 PM

I do have the idle screw on the throttle body. But i dont think there is one on the MAF. I aslo have the cold start switch, I have a complete spare housing with the cold start switch, and other bimetallic sensors ( EGR) and Purger canister sensor. I was gonna changed the whole housing with complete sensors, but i will first look at the water temp sensor. I will aslo completely close the idle screw, but then i believe the idle will be pretty low. like 700 rpm or less.

Jman · 10-10-2003, 05:59 PM

Oh, i just looked at the pic ,mine is like that, but what is #6 on the pic?

Jerry

drdma · 10-11-2003, 12:12 AM

No. 6. is oil pressure (level) sensor.

If You close the idle screw, wait some time (a day?) for the computer to re-learn the ISV opening position. Idle your engine for some time.

Jman · 10-11-2003, 01:43 AM

Oh yes the oil pressure switch, I did read in the manual that the computer needs to be reset or driving for some time( for the other celica engines ) to learn the new idle position, I will close the idle screw and reset the computer and drive it around to see if it will work

Thanks

Jerry

Jman · 11-30-2003, 01:50 AM

closing the idle screw did not help...my next step is to clean the throttle body and change temp sensor....I notice the temp gauge never goes half way...the most is 1/4. Also thinking fuel delivery problem

drdma · 11-30-2003, 03:07 AM

Check the water temp. sensors resistance at low and at high temperatures. Check it against the characteristics can be found in the BGB.

zyg0te · 12-01-2003, 02:07 AM

thats nothing compared to my 89 gt idling at 2200.... when it ran =(

PsychoCelica · 12-18-2003, 03:11 PM

My '87 GTS idles at/around 1000 and seems boggy and vibrates alot when in the 750 range. I think your idling is normal.