My 20V SVT idle sucks, need help...

[shizilki]

Good day to all Toyota members,

Need help to identify what's the cause for my engine bad idling. When i start cold, the RPM doesn't ram high then goes stable like it should. The needle just crawls slowly. Another thing is the idling never maintained. Sometimes 1.2k, 1k, 1.5k, below 1k isk...isk
i fren of mine said maybe autochoke problem. i got no idea where this is located. So, really need help from all sifu's out there

Thanks a bunch

 

[scottwrx]

of you have juz restart you ecu, then it is normal..
but if there is not the case then u need to check your tps or your engine head.. have u done any port n polish??

 

[danny_rigid]

idle valve is below the 4th intake plenum........a very hard thing to replace! Make sure check everything first!

 

[TRD.AE92]

ISCV clean already?

 

[banzai]

clean your ISCV and throttle body. take it out individually and run it through with a good carb cleaner & petrol. you will feel the difference.

 

[suma_]

try swap AFM with a good one. AFM is very prone and for aging SVT, it can be the main culprit.

 

[shizilki]

port n polish done along with throttle body, maybe i'll try resetting the ecu tomorrow.
ICSV, very hard to pull out, tried it before.
AFM....mine just being serviced & adjusted last month. Mechanic said still functioning well
Anything on the autochoke?

 

[levin818]

At stock setting, when you start the 20V, the rpm should goes up to ~1200rpm and stay there, if it is at cold start, or bounce back to ~800rpm, if it is at working temp. If your rpm climb up slowly, then its your ISCV is dirty. You need not pull out the ISCV for cleaning. I think Chinozie has some good idea to clean the ISCV without pulling it out. ((( Paging Chinozie ))). You are wanted
As far as i concern, the Throttle Opener that attach behind the 4-throttle act as auto choke. Before vacuum is exist (before started the engine), it slightly push open the butterfly, just like the paddle is being push down slightly. When vacuum is exist, it let go the butterfly. There is a screw to adjust the opening angle of the butterfly. Some tuner use this screw to bypass the ISCV and control the idling. But by doing this way, TPS need to be re-adjust together.

 

[levin818]

Adjust Throttle Opener - refer to BT service manual EFI pg.53

 

[shizilki]

wong is it? u sold me the svt ecu before. we met at petronas station near kota kemuning. i'm going to Puchong tomorrow, maybe can meet u to troubleshoot what's the problem is

ecu resetted, still the same
maybe i'll go for ISCV after all
Thanks for the info guys

 

[levin818]

Hi Shizilki, yes its me
If the problem never resolved, no matter how many times your reset the ECU, it will come back.
I'm worried i can't meet you tomorrow coz i'm leaving to JB on tomor morning.
Next Monday is Ok?

 

[cruiser78]

port n polish done along with throttle body, maybe i'll try resetting the ecu tomorrow.
ICSV, very hard to pull out, tried it before.
AFM....mine just being serviced & adjusted last month. Mechanic said still functioning well
Anything on the autochoke?

I think SVT or BLT dont have autochoke. Autochoke only can be found on carburetted engine which has a water line going into carburettor. Autochoke function is determined by water temperature. 4AGE have its cold idle control system by using its ISCV. ISCV opens or closes according to water temperature too but it also uses other value such as aircond signal, throttle position, intake air temperature and some other things too, just my thought...

 

[shizilki]

Hi Shizilki, yes its me
If the problem never resolved, no matter how many times your reset the ECU, it will come back.
I'm worried i can't meet you tomorrow coz i'm leaving to JB on tomor morning.
Next Monday is Ok?

hehe i'm at KL for only 1 day today, tonite going back to t'ganu. Sudah serabut la dgn idling tk betul ni

I think SVT or BLT dont have autochoke. Autochoke only can be found on carburetted engine which has a water line going into carburettor. Autochoke function is determined by water temperature. 4AGE have its cold idle control system by using its ISCV. ISCV opens or closes according to water temperature too but it also uses other value such as aircond signal, throttle position, intake air temperature and some other things too, just my thought...

thank you for sharing, maybe need to send back my car to my mechanic at balakong to adjust the TPS n also clean the ICSV

 

[FGT]

of you have juz restart you ecu, then it is normal..
but if there is not the case then u need to check your tps or your engine head.. have u done any port n polish??

do u know any good workshops around pj or damansara to do port n polish + throttle body + injection service for 4afe?

 

[pcmoddingmy]

shizilki: I think maybe just change the throttle body with another one. Might help resolve your issue if you cant find anyone to set it properly. If can, try to post up a video of you engine RPM when starting up until idling.

 

[shizilki]

shizilki: I think maybe just change the throttle body with another one. Might help resolve your issue if you cant find anyone to set it properly. If can, try to post up a video of you engine RPM when starting up until idling.

ok, i'll try to post the vidoe later on

to FGT, port n polish for my car done at balakong, there's a Sabahan mechanic there

Thank guys for the help

 

[shizilki]

guys thanks 4 the info especially to levin818 aka wong who really2 helped me tackle the problem here in kerteh the main problem was the distributor spoiled already. the rest was dirty throttle body n ISCV which levin818 helped me to clean it. he adjusted the TPS n throttle opener. the result was...better idling n better response.
again thanks guys n levin818 for the DIY stuff tutorial. u have my gratitude
"live long n prosper"

 

[levin818]

From Shah alam all the way to Kerteh.... haha
For optimum result, you may want to completely strip down your 4-throttle for a good cleaning job.

 

[chinozie]

yaaa...since EFN is back...i wonder can he do the TB service... hmmmm...

 

[shizilki]

From Shah alam all the way to Kerteh.... haha
For optimum result, you may want to completely strip down your 4-throttle for a good cleaning job.

yup, that will be my next DIY project. Thanks a lot guys

 

[ee90kl]

bro,my svt when cold start,rpm din goes up,it around 800rpm.if i press d pedal abit,d rpm wil become unstable,goes up n down between 400 n 800,it feel like wan 2 die out.
But if i leave it warm up itself,after few mins,everything is ok n idle stable.
Juz face tis prob recently,b4 tat when cold start,rpm wil goes up to 1200.
Wats d prob?
Tq

 

[et_box]

Same problem. During cold starts the rpm is normal. Once i press the accelerator, the rpm drops and i have to press harder to compensate.

The engine feels like dying until when it has warmed up sufficiently, it becomes normal.

So strange... wonder what is wrong... Car also feels a bit underpowered too..

 

[levin818]

Idling problem at cold start - clean your ISCV + 4-throttle
Underpower - check your TPS & Timing's setting

 

[me2kimi]

What is function of the screw at AFM? I remember last time when idle suck during aircon on, the foreman re-wired aircon vsv (maybe the vsv did not switch on). After wiring done the idle still suck the he adjust the screw at afm. SO what actually the screw use for? Some said do not touch the screw.

 

[me2kimi]

What is function of the screw at AFM? I remember last time when idle suck during aircon on, the foreman re-wired aircon vsv (maybe the vsv did not switch on). After wiring done the idle still suck the he adjust the screw at afm. SO what actually the screw use for? Some said do not touch the screw.

---------- Post added at 11:49 AM ---------- 6 hour anti-bump limit - Previous post was at 11:38 AM ----------

What is function of the screw at AFM? I remember last time when idle suck during aircon on, the foreman re-wired aircon vsv (maybe the vsv did not switch on). After wiring done the idle still suck the he adjust the screw at afm. SO what actually the screw use for? Some said do not touch the screw.