Power loss '91 3-FE (1 Viewer)

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Jun 6, 2017
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I took it off the truck but I was told not to remove the lid. They said it was a bitch to get back on. Do you know anything about that?
So, I didn't have the time to open mine at the time but I still have it as I never returned it as a core. If you look at the thread I posted before there's a good picture of the top off. But basically it's a 90* barn door kind of gate that's actuated by the ECM to regulate free air to the engine based on throttle position to compensate and correct towards stoich.

Do you have any codes being thrown (or stored)? I was able to diagnose mine when it finally stored a code when it dropped out while I was driving one of the times. The code was a short/open for a circuit in the AFM on mine.

What specific symptoms are you having?
 
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Also. The 4.5 1FZ from 93-97 is a totally different engine than the 4.0 3FE out of the 91/92. So you might want to search around in that vein before chalking it up to the same scenario as a 3FE. Just my 0.02.
 
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basically it's a 90* barn door kind of gate that's actuated by the ECM to regulate free air to the engine based on throttle position to compensate and correct towards stoich.
Negative. The flap in the AFM is moved by airflow through the intake. The ECU reads the position of the flap to determine the amount of air ingested. There is also an air intake temperature sensor that the ECU uses for fuel trim along with a switch that fires the secondary fuel pump logic when the flap in the AFM opens.
 
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Negative. The flap in the AFM is moved by airflow through the intake. The ECU reads the position of the flap to determine the amount of air ingested. There is also an air intake temperature sensor that the ECU uses for fuel trim along with a switch that fires the secondary fuel pump logic when the flap in the AFM opens.
Ah. Good to know. My mistake. Does that help the 4.5 guys? Is it the same?
 

Eicca

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Glad to hear you fixed it, and thanks for the info on the 93 Camry V6 AFM.

Our family 3FE had a stumbly issue last year—would randomly cut out under load but idle totally fine and drive fine 95% of the time. A replacement throttle position sensor seems to have fixed that one.

Lack of parts will kill these engines before they die of natural causes.
 
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Ah. Good to know. My mistake. Does that help the 4.5 guys? Is it the same?
There are 2 different versions of the 1FZ-FE. The OBD1 (93-early 95) has an AFM similar in operation to the AFM in the 3FE, but different part numbers and not swappable between the 2, although I have not personally researched this.
The OBD2 version (95-97) has a MAF sensor as opposed to an AFM. Different animal altogether.
An AFM has a mechanical flap that moves the armature of a variable resistor.
A MAF sensor has a small sensor mounted inside the unit that measures air volume. It also contains an air intake temp sensor.
 
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