Carburated 1.6L Feedback Fuel Control System question - Toyota Nation Forum : Toyota Car and Truck Forums

ChrisW01 · 06-30-2011, 02:01 PM

Good day and hello to the forum.
My name is Chris & I'm helping a friend with his 89 Corrolla. Having read several posts there's several knowledgeable folks here so I thought I ask this question.

Like the subject line says could someone provide me with an explanation of the Feedback Fuel Control System "for the Corolla model" (or scan from Toyota service manual). It's my understanding the system requires 4 inputs: RPM, Throttle switch, coolant switch (BVSV), and vacuum switch before the O2 sensor comes into play, is this correct? Also how is the fuel/air ratio controlled in the higher RPM ranges of 1600-4000? Is it by venting air into the air cleaner or is the Fuel Cut Solenoid actuated in this range? The Haynes manual only has basic info & there's nothing online specific to the Corrolla.

Sorry for being long winded. Any clarification or explanation is appreciated.

Thanks in advance for your patience
Respectfully
Chris........

ChrisW01 · 07-01-2011, 12:09 PM

Well I guess my question was a bit loaded, no worries. Just to add to the discussion, after a little more research (interestingly some of it found in this forum) the carb on this model (2 barrel) has a primary & secondary venturie each with it's own solenoid which is how I assume the ECU maintains the fuel/air ratio once it's off the throttle switch and in the higher rpm ranges. Maybe Carburetor 101 for some but a good review for myself. If anyone has some thoughts or corrections to add to this and my earlier question it would be appreciated.

Thanks in advance for your patience.
Chris........

90 GP · 07-01-2011, 06:15 PM

Here's a writeup explaining feedback system on on A Tercel 1.5. Assume the 1.6 would operate i the same manner.

http://repairnet.aircare.ca/document...yotatercel.pdf

ChrisW01 · 07-01-2011, 07:52 PM

Thanks 90 GP

I've read that write up, it's what I based my original question on. Like you said I'm sure the Tercel & Corolla Feedback system follow similar lines. The Corolla from what I've seen does not have the same style, use or location of EBCV. Was hoping to learn something from the Corrolla FSM regarding when the primary & secondary solenoids are active from idle to the higher rpm ranges. I think I've got a good sense from that write up where they kick in.

Much appreciated your reply!