Issue with 20v BT

[JustinMV85]

Hey guys,
Need some advice, just had a 20v BT transplant into an SEG corolla. I don't know what's the problem but i think a few other 20v BT swappers may have faced the same issue, pls share how this can be fixed. My engine is sluggish and and bogs below 3k rpm, at standstill if i rev full it might even bog and hang at 3k rpm for sometime before shooting higher, if i rev slowly though, then no problem. Fuel consumption high due to this problem =( It also tends to come and go, sometimes its fine and seems perfect then suddenly it's back to being this way. Please if anyone has pointers and advice, or have faced similar issues, I'm all ears. Thanks =)

 

[nicholas1007]

mine one also same, sluggish below 3k rpm. mine one is Auto. my case, if high rev a few times then becomes better. i've clean the TB, change plugs, fuel filter before. recently change exhaust system, Walbro fuel pump & AFR & my fuel consumption is shooting high. now planning to change bak to DENSO fuel pump.
Future Planning:
Will try to put in CAI & performance drop in filter or mayb the way suggested by 1 of the forummer (tonyops) - APEXI Dual Funnel Air Intake.
Will try put in a Unichip Piggyback.

 

[meg_omen]

try to diagnose it... any check light...
too sluggish below 3K rpm... check the following...
- O2 sensor
- knock sensor
- ecu

good luck!

 

[nappx]

Meet right mech..contact HAZ Garage..it might can solve ur prob..

 

[JustinMV85]

Thanks guys for the replies,
apparently this problem is quite widespread, ive been reading many forums and doing research on this issue and many other 20vBT transplant owners face it too. Here is what i found on one forum. I will copy paste it here.

"there is a big long thread on this issue in the toyspeed faq. this only applies if it hesitates only when cold and using the factory 20v BT ecu. these other guys reckon it happens at 3000rpm

there are a few common causes.
one is a dead 02 sensor. some say these can be fixed by pulling out and heating it up to burn off the carbon... (butane torch etc) which is usually caused by the burning off of oil from the cam breathers. (blow by oil from the rings or valve seals). easily fixed by installing an oil catch can to the cam breather including the pcv valve. personally its an excuse to do a huge skid to get the exhaust glowing heh heh, that'll cook any carbon off.
check 02 sensor by measuring the output voltage when car is running and 02 sensor is hot. stoichometric (sp) is approx 0.5v but should range between 0v and 1v if you're getting 0v out of it.. its dead. (dont measure the power wires either)

some say they fixed it by cleaning the throttles. whether its gunky around where the throttle shuts off or if the vacuum ports to the map sensor are blocked i don't know.

then there's the map sensor.. check there's no damage to the vacuum hose to the map sensor. check the plug is good and the wiring is not damaged."

---------- Post added at 10:56 AM ---------- 6 hour anti-bump limit - Previous post was at 10:51 AM ----------

1) Nicholoas : yup, i tried a few similar things too, spark plugs, TB cleaning, exhaust systems, but apparently its just a matter of the sensors getting a wrong reading. =(

2) meg_omen : Thanks! appreciate it! Ill check those 3 things =) btw, no check light.

3) nappx : Thanks buddy, any contact? where is HAZ garage located?

 

[chinozie]

Yup it's true...it's the most common problem with 20V...

Years back a few of the seniors member in ZTH Toyota had the same problem...
I've also been searching for answers Globally...turn on the same answer like you...

I've even trouble shoot it and narrow it down myself , and help from my colleague , GT20V (Pendekar Zul) ...everything was done...

in the end...it narrows down to a better setting of FPR and O2 sensor...and yes need to clean your throttle body...because right after I've fully overhauled the engine the problem seems to be disappeared...yet still using the old used O2 sensor from chopped shop...

 

[nicholas1007]

i try to look for the O2 sensor. where is it located? coz last time my mech check, there is no O2 sensor!!

 

[JustinMV85]

Thanks chinozie, appreciate the advice, ill check and update soon! *fingers crossed* =)

 

[nicholas1007]

here is my ecu photo taken, is there any problem?

BTW, can anyone tell me where is the location of the O2 sensor. i cant find it in my engine bay.
thx

 

[meg_omen]

it's below the steering rack area, attached closed to the end of your extractor...

 

[lkeong88]

Before you go through all the troubles, why don't you check your ignition timing at the distributor? 1 degree difference make alot of difference in acceleration, when mine was set to 10, it accelerated very easily and the car feels lively but there is audible knocking

 

[alex_khoo]

Meet right mech..contact HAZ Garage..it might can solve ur prob..

bro nappx...where HAZ garage in and contack num? mind to share here?

 

[levin818]

mine one also same, sluggish below 3k rpm. mine one is Auto. my case, if high rev a few times then becomes better. i've clean the TB, change plugs, fuel filter before. recently change exhaust system, Walbro fuel pump & AFR & my fuel consumption is shooting high. now planning to change bak to DENSO fuel pump.
Future Planning:
Will try to put in CAI & performance drop in filter or mayb the way suggested by 1 of the forummer (tonyops) - APEXI Dual Funnel Air Intake.
Will try put in a Unichip Piggyback.

Keep your car at standard then it will not have problem
You may want to check the following:
- O2 condition
- TPS position
- Ignition timing
- fuel pressure

If you plug in CAI, drop in filter and Unichip and intend to resolve the problem, this it is defenately not cost effective.

 

[nicholas1007]

Keep your car at standard then it will not have problem
You may want to check the following:
- O2 condition
- TPS position
- Ignition timing
- fuel pressure

If you plug in CAI, drop in filter and Unichip and intend to resolve the problem, this it is defenately not cost effective.

May i know how to check TPS position. I open the engine oil cover, i c sludge inside the engine. Do this affect the performance also?
I will try to take a few picture.

 

[levin818]

See the attach pic. You can get it from BT sevice manual pg. FI-45.

P/S: you need to apply a vacuum to disable the throttle opener before you can insert the filler gauge between the throttle stop screw and throttle lever.