Corolla 03 running rich!

[OwaisYunus1]

@hash4u What could cause an altered timing? Since the timing is not manually adjustable.

[OwaisYunus1]

Any response from the members would be appreciated...

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[waqar19]

Have you checked its MAF sensor visually ?

[SER_GTR]

The XLi/GLi Have This Issue That From No Where They Started Behaving Strange And Dumping A Lot Of Fuel.....!

Have You Test Check Your Coil packs????? Also Check Your Main Load Sensors....MAF/TPS....It Don't Have O2 Sensor I Guess But Have A Variable Resistor In Place.....!

Check All These Things.........All The Sensor Readings To ECU Should Be Normal.....!

I Don't Know About 2nZ-Fe Coolant Operating Temp But As I Know......97 Is On High Side......100 Is Boiling Point....! It Should Be Under 90's

[SER_GTR]

If This Thing Still Behave Same........Its Your ECU....Physically Check It....Or I Would Have Hook VAFC 2 With It And Wideband And Lean Adjust The AFR's To Desired Levels.....LOL

Easy Way Out....

[Xulfiqar]

check the injector duty cycle and check that the injectors are not leaking themselves.

[OwaisYunus1]

Thank you for the responses.
@waqar19. Yes I've checked the maf sensor visually and its intact.
@ser_gtr. How would I test the MAF and the TPS? About the temperature, that's what had me concerned too. I opened up the coolant temperature today and tried on two different ones from a local kabariya. With one of them, the car behaved the same way while the other one caused it to become even richer. So I cleaned off the residue on the original sensor and put it back in. And come to think of it, VAFCII is not a bad idea but I'd like to fix the car with the stock setup
@xulfiqar. I pressure tested the injectors individually for leaks by placing them in a pipe filled with carb cleaner and then pressurizing them with compressed air, in short, the injector cleaning method and they did not show any leakages. For the duty cycle, I tested each injector by connecting an led to the injector grips. Is that the right method?

[SER_GTR]

You need To Look For Their Readings To ECU....You Need To Follow Manual......! Look For Manual And Check For Their Appropriate Reading.....!

[SER_GTR]

Yes.....Have Patience And Check Every Sensor Hooked Up With ECU........You Will Find Something....If You Don't.....Its ECU I Say...!

[wasay_ahmed]

check it valves clearance? r plugs oily or dry?

[OwaisYunus1]

@ser_gtr I guess i'll have to find a way to get the scanner working and then will report back here.

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[OwaisYunus1]

@wasay_ahmed. I changed the plugs a couple of weeks back. The plugs were dry when i took them out.

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[SER_GTR]

Use A Proper Scanner...Don't Use Crappy Scanners Which Tells You Lame Results...

[OwaisYunus1]

@ser_gtr I've arranged for a guy whose working on the other car to attach his scanner which I think is a Tech 2. Lets see what shows up.

[SER_GTR]

B.t.w....How Many Miles It Does And Ever RUN On CNG Before????

Did You Compression Test The Motor?????

[Xulfiqar]

Thank you for the responses.
@waqar19. Yes I've checked the maf sensor visually and its intact.
@SER_GTR. How would I test the MAF and the TPS? About the temperature, that's what had me concerned too. I opened up the coolant temperature today and tried on two different ones from a local kabariya. With one of them, the car behaved the same way while the other one caused it to become even richer. So I cleaned off the residue on the original sensor and put it back in. And come to think of it, VAFCII is not a bad idea but I'd like to fix the car with the stock setup
@Xulfiqar. I pressure tested the injectors individually for leaks by placing them in a pipe filled with carb cleaner and then pressurizing them with compressed air, in short, the injector cleaning method and they did not show any leakages. For the duty cycle, I tested each injector by connecting an led to the injector grips. Is that the right method?

the noid light (LED) is for testing pulse output to the injector, duty cycle is tested from a live scanner in which you can see the output of the ECU to the injectors, if that goes messed up your engine may flood with fuel. btw I once came across such a problem in a Vitz, it was a piece of natural fibre stuck between the sense filaments of the MAF sensor. If you see it too, handle it extremely carefully, you dont want to break those filament wires.

[OwaisYunus1]

@ser_gtr It used to run about 7-8km/l and that too with a very light foot. Havent checked the compression, though the engine still performs the way it used to years back.

Thank you all for your kind responses. I've changed the MAF sensor and the car is not running rich any more. I'll drive it for about a week and report here how it's doing on fuel and if it stays well with the replaced MAF sensor

[OwaisYunus1]

@xulfiqar. I checked the MAF sensor physically. Though it did not have any issues with it physically but upon replacing it, it seems to have fixed the issue. It did not show a CEL related to the MAF sensor though with the old sensor.

[SER_GTR]

Main Load Sensors ..Mostly MAF's ...........Good To See Its Going Good...

Check With Fuel Avg And Report Back Here ......!

Chao

[adeelnasir143]

This very old thread but issue seems to be the issue of varaiable resistor nothing else because it doesn't have O2 senser snd this Trimport adjust AFR