help!! my 20v idling problem!!

nicholas1007

500 RPM
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Mar 20, 2006
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yup. better in response. the hissing sound is loud after running for a while. i scare AFR too rich. i wan to install piggybak, but currently no budget for tat. so asking if no install piggybak at the moment ok or not
 

alex_khoo

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Apr 17, 2006
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banyak sakit kepala now...haiz...my car tat day done
- Clean ISCV
- Clean 4-throttle (strip into piece)
- Check all vacuum leak and change many hose
-clean airflow meter
after drive 2/3 day then the idling back to b4!!!:banghead::confused:
 

feipepe

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May 12, 2010
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ALEX KHOO,
if i'm not mistake, i think ur AFM sensor is faulty. last time i also have found this issue before, after clean ISC, throttle body more than 3 day, the idle problem coming back again. after i tries to buy another chop shop AFM, and tries to adjust the bypass screw at the AFM (chop shop), until now more than half years so far no problem.
 

D7zul

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Feb 24, 2011
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banyak sakit kepala now...haiz...my car tat day done
- Clean ISCV
- Clean 4-throttle (strip into piece)
- Check all vacuum leak and change many hose
-clean airflow meter
after drive 2/3 day then the idling back to b4!!!:banghead::confused:
i also have this idling problem..

this is what i think..

MAP is better than AFM..

so, better use MAP sensor.. :biggrin:

i also planning to change the whole wiring of my SVT.. also my auto gbox to 6speed..

awaiting funding :biggrin:
 

beyond

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Sep 14, 2005
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KayEL
I m having odd problem with my BT too. If AC on to the max. When I slow down to stop. The engine will mati.

Anyone knows what s wrong with the car?
 

cuscostrutbrace

500 RPM
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Jul 10, 2004
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Early SVT wiring mated to BT ecu,need a/c idle up valve for a/c idle up
Late SVT wiring mated to BT ecu,not need a/c idle up valve

There is a difference in a/c on signal input to ecu between those two models,if your stock SVT ecu last 5 digit part number is 12770/12771 = u have early model svt,if 1A190 = you have late model,if your SVT is auto(ealy or late),then no problem with a/c idle up.

Levin 818,am i correct with this info,or you have new experiment,hehe
 

me2kimi

500 RPM
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Jun 25, 2007
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Hi all, just wanna share my experience.
I've converted my car to this spec:
SVT wiring mated BT ecu with BT aircon compressor.

And my stock SVT ecu is like this, donno early or later model.


What I notice is idle up valve is not active anymore after using BT ecu.
Thus, I've also experience engine stall intermittently.
From my observation, my engine will stall immediately when I release throttle pedal.
After sometimes, I've DIY narrowband O2 sensor for monitoring.

What I get it, at the time I release throttle pedal i saw the narrowband sensor is too lean.
This is becoz fuel cut at that time and I also noticed that RPM gauge is at around 600rpm.
Sometimes it goes as low to 500 rpm and engine jerks a while before fuel is supply again.

What have I done is I increase fuel pressure using FPR (my AFR is still ok after tested with wideband).
So as a result, my engine is less stall now but still I felt it jerk at fuel cut time.
 

cuscostrutbrace

500 RPM
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Jul 10, 2004
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Hi all, just wanna share my experience.
I've converted my car to this spec:
SVT wiring mated BT ecu with BT aircon compressor.

And my stock SVT ecu is like this, donno early or later model.


What I notice is idle up valve is not active anymore after using BT ecu.
Thus, I've also experience engine stall intermittently.
From my observation, my engine will stall immediately when I release throttle pedal.
After sometimes, I've DIY narrowband O2 sensor for monitoring.

What I get it, at the time I release throttle pedal i saw the narrowband sensor is too lean.
This is becoz fuel cut at that time and I also noticed that RPM gauge is at around 600rpm.
Sometimes it goes as low to 500 rpm and engine jerks a while before fuel is supply again.

What have I done is I increase fuel pressure using FPR (my AFR is still ok after tested with wideband).
So as a result, my engine is less stall now but still I felt it jerk at fuel cut time.
Sifu Levin 818,can you identify that ecu,i also came across this ecu once...
 

levin818

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Nov 29, 2003
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Wow... this is brand new ECU that previous car owner bought from DENSO. Date code could be 1999 or 2000. Much more newer than stock (1992~1994)! From DENSO code, it looks like mated with 89661-12771. If you can show the internal picture, i will be able to identify.

Rahmat, my car is running with '92 A/T wiring but it can run with all auto and manual ECU w/o any problem on the A/C system (run manual ECU with converter). So i still think that those ECU deliver tha same level of signal to the A/C controller... But thinking of which, there are R12 and R13 aircon gas being use in Silvertop so signal level might be difference in difference gas. But jus that i did not experince any significant difference on those ECU.

---------- Post added at 06:06 PM ---------- 6 hour anti-bump limit - Previous post was at 05:57 PM ----------

I have run a converter on my silvertop wiring to accept BT ECU. The result is good on the idling and eventhough with A/C turning ON/OFF.
If your idling is too low probably your conversion of the signal is not right or ISCV is clogg.

---------- Post added at 06:08 PM ---------- 6 hour anti-bump limit - Previous post was at 06:06 PM ----------

Alex, go find back your ori trumpet and rubber hose clamp (for AFM and Surge tank). Those are the area that you have vacuum leak.
 

bryanl5636

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Sep 12, 2008
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My b.t also need help,engine slumbing during 1st and 2nd gear,rpm below 3,000
But high rev is ok,did any one know wats going wrong?I already try to adjust ignition timing,replace s.plug,s.plug cable,fuel pump and sard fuel regulator:......
 

me2kimi

500 RPM
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Jun 25, 2007
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Here is picture as per requested

 

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levin818

1,000 RPM
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Nov 29, 2003
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Visit site
Its for 89661-12771

---------- Post added at 02:29 AM ---------- 6 hour anti-bump limit - Previous post was at 02:27 AM ----------

My b.t also need help,engine slumbing during 1st and 2nd gear,rpm below 3,000
But high rev is ok,did any one know wats going wrong?I already try to adjust ignition timing,replace s.plug,s.plug cable,fuel pump and sard fuel regulator:......
TPS setting is out, or O2 is dead.
 

cuscostrutbrace

500 RPM
Senior Member
Jul 10, 2004
987
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Wow... this is brand new ECU that previous car owner bought from DENSO. Date code could be 1999 or 2000. Much more newer than stock (1992~1994)! From DENSO code, it looks like mated with 89661-12771. If you can show the internal picture, i will be able to identify.

Rahmat, my car is running with '92 A/T wiring but it can run with all auto and manual ECU w/o any problem on the A/C system (run manual ECU with converter). So i still think that those ECU deliver tha same level of signal to the A/C controller... But thinking of which, there are R12 and R13 aircon gas being use in Silvertop so signal level might be difference in difference gas. But jus that i did not experince any significant difference on those ECU.

---------- Post added at 06:06 PM ---------- 6 hour anti-bump limit - Previous post was at 05:57 PM ----------

I have run a converter on my silvertop wiring to accept BT ECU. The result is good on the idling and eventhough with A/C turning ON/OFF.
If your idling is too low probably your conversion of the signal is not right or ISCV is clogg.

---------- Post added at 06:08 PM ---------- 6 hour anti-bump limit - Previous post was at 06:06 PM ----------

Alex, go find back your ori trumpet and rubber hose clamp (for AFM and Surge tank). Those are the area that you have vacuum leak.
Wong,yes you're correct...if your wiring is SVT auto,then it would not have a problem to accept BT auto/manual ecu,also the a/c will not affected because the SVT auto a/c signal to the ecu is same with blacktop auto/manual.

The problem only when converting SVT manual to BT ecu,but so far i've done almost 20 SVT to BT conversions,so far no customer complaint on low idle,for such conversion,it is necessary to use a/c idle up valve.

And also when convert to BT ecu,some may go the 'trumpet' route,hence the low end fueling is greatly affected,a fuel pressure regulator will usually fixed this.Also i will suggest to each customer to fit blacktop O2 sensor for proper running (although most of them didnt bother)...

---------- Post added at 08:35 AM ---------- 6 hour anti-bump limit - Previous post was at 08:33 AM ----------

Here is picture as per requested

I think the caps look different than the earlier svt ecu isnt it Wong...