Restoration of Corolla 1994 & 7afe Swap

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aziz.rehan (Rehan Aziz) 2020-09-16 23:24:40 +0500 #991

Check basic things like cleaning of throttle body,spark plugs,clean fuel injectors(they may be giving more fuel than required when they get clogged).How is condition of transmission oil and filter.And also do compression test on all cylinders to check engine health.Which oil and grade do u use??

mujtabaayan (mujtabaayan) 2020-09-16 23:52:58 +0500 #992

Throttle body cleaned, injectors changed, transmission oil is new, using zic 10-40, compression test is not done but there is absolutely no issue of oil burnig/decrease

aziz.rehan (Rehan Aziz) 2020-09-17 00:07:35 +0500 #993

Has the car previously been run on cng?

humayun.chughtai.7 (Humayun Azhar Chughtai) 2020-09-17 06:28:21 +0500 #994

Got these from gariparts.pk They are based in karachi.
https://www.gariparts.com

humayun.chughtai.7 (Humayun Azhar Chughtai) 2020-09-17 06:33:52 +0500 #995

Is the T-stat installed ? It is a must thing.

mujtabaayan (mujtabaayan) 2020-09-17 23:31:32 +0500 #996

Where it is located , i mean how to check it?

mujtabaayan (mujtabaayan) 2020-09-17 23:32:56 +0500 #997

You mean thermostat, then yes its installed and fan is automatic

humayun.chughtai.7 (Humayun Azhar Chughtai) 2020-09-18 06:46:01 +0500 #998

Then just try to live with it.

aziz.rehan (Rehan Aziz) 2020-09-18 22:20:54 +0500 #999

Maximum u will increase 1 km average in local drive.Ur current average is fine being Auto.Just drive sensibly and check brakes,they might me dragging.

mujtabaayan (mujtabaayan) 2020-09-19 08:17:23 +0500 #1000

Thanks. Means 8-9 km/ltr is normal consumption for these engines Brakes are fine and were serviced recently.

humayun.chughtai.7 (Humayun Azhar Chughtai) 2020-09-19 14:28:19 +0500 #1001

With auto transmission & urban driving, Yes its kinda normal.

hamadkhalil79 (Hamad khalil) 2020-09-20 01:57:18 +0500 #1002

Is there black soot in the exhaust tip / rotten egg smell from exhaust? Also , what is your idle rpm ? With and without AC .

mujtabaayan (mujtabaayan) 2020-09-20 13:44:49 +0500 #1003

No, its colour remains like orange. RPM remains at 800 at idle

humayun.chughtai.7 (Humayun Azhar Chughtai) 2020-09-22 06:37:47 +0500 #1005

Few days back, bought this DMM, just to get some authentic values from different sensors.

humayun.chughtai.7 (Humayun Azhar Chughtai) 2020-09-22 06:47:09 +0500 #1006

Next day took readings of different sensors by back-probing them & wrote the values down for future reference, if something goes wrong in future.

1- Took resistance readings of ECT 1st at cold start, 2ndly when rad fan came ON & 3rd when it went OFF.

Sensor back-probed with the help of needles, as I wasn't willing to damage/cut wires.

DMM attached.

humayun.chughtai.7 (Humayun Azhar Chughtai) 2020-09-22 06:50:38 +0500 #1007

TPS back-probed as well, if you zoom out the pic, you will see a needle probed into the signal wire.

humayun.chughtai.7 (Humayun Azhar Chughtai) 2020-09-22 06:52:42 +0500 #1008

Getting values by MAP sensor.

humayun.chughtai.7 (Humayun Azhar Chughtai) 2020-09-22 06:56:14 +0500 #1009

Tools used

Data collected.

humayun.chughtai.7 (Humayun Azhar Chughtai) 2020-09-22 07:14:38 +0500 #1010

Now lets come to the main issue. I am NOT getting any feedback by the oxygen sensor halankay its getting 12v for heater in 2 pins & GROUND by ECU in 3rd pin but it isn't throwing any feedback voltages to the ECU.

It should throw something betweem 0.1 ~ 0.9v but all I am getting is 0.01v when I back probe both the signal wires i.e. blue & white.

This white wire is GROUND, as I can hear the continuity buzzer when I attach one lead to it & other to the negative terminal of battery.

P.s. engine was at optimum operating temperature during all these tests.
And the resistance between the 2 pins of o2 heater circuit is 11 ohms, which seems to be in spec.

Now I have 2 things in mind ...
1- Either the OX pin on the Ecu Is not connected with this o2 sensor.
2- otherwise our o2 sensor is bad.

Took out part number of oxygen sensor through "Toyodiy", it came out to be 89465-22180 & upon further googling got to know that this is not a wideband o2 sensor.
As my engine is 7afe Leanburn, so it doesn't uses wideband o2 sensor.

I tried to put forward everything as much clear as possible, need your suggestions.
@SER_GTR @Xulfiqar & other respected members.

humayun.chughtai.7 (Humayun Azhar Chughtai) 2020-09-22 07:32:29 +0500 #1011

Again after some more googling, I confirmed that my 7afe is a leanburn version.
- It has flaps inside the intake manifold, which opens/closes through a diaphragm when a vsv valve gets signal from ECU.

- Injectors are directly ported into the head & not on the intake manifold.
- CPS sensor (Combustion Pressure Sensor)
- Different type of non-adjustable distributor
- Ignitor installed separately on the strut tower (not in the dizzy).
- 4 wire heated o2 sensor

And you guys would be surprised to know that this is the LEAST powerful version of 7afe & generates around 105~110 hp only but on the other hand, it's the most fuel efficient version of 7afe as well.

Btw this 7afe LB in my car came out of a 1995 Toyota Carine E (AT-191), mostly sold in Russia & Europe.

Another important piece of info, just in case