How does the 4age AFM system work?

[heshan]

I'll check about the air supply leaks after the AFM..

No fault codes on the ECU.

I have the O2 sensor from my old 4age put onto my GZE. I'll try clearning or replacing that first then.

Thanks buddy

[oldeskewltoy]

Although the cat may be old... and maybe tired... you have the right idea with checking the tune-up parts.

Replacing cap, rotor, wires, plugs, filters(air, fuel and oil) . I would also remove the grond connection on the battery while you do the tune up. this will make any "accidents" less likely to cause a problem, AND by disconnecting the batt you clear all codes.

Take it out after you get everything re-assembled, and the batt reconnected and drive it hard(3k+ rpm) for more than 15min and then take it to check emissions.

IF after the tune up the emissions are still high... then look @ replacing the cat.

[heshan]

Thanks buddy.

I'm also going to check for vacuum leaks..

[heshan]

Guys, just wanted to give an update and also post a new question..

We cleaned up the throttle body, injectors and rechecked timing and my emissions issue reduced considerably.

BUT.... my test still fails at idle.. I'm idling around 1000-1100 rpms and my CO levels are over the allowed limit.. Do you think if I reduce my rpm to around 700 would my CO levels drop?

What can cause idle CO to be over and high rpm levels to be less than half the legal limit?

[heshan]

Guys, anyone with some idea why the idle CO levels r high?

Any tips on what I should do to get this sorted?

[Ivan141]

Burning some oil perhaps? My old engine couldn't pass CO anymore either, it left clouds of smoke whenever I drove off with haste.

[heshan]

Well the high RPM test passed.. Its the IDLE test that failed.. The high RPM test was having 50% of the legal CO levels and IDLE was on the legal limit so they failed me

If its oil that's burning then does that mean I need to rebuild the engine?

[heshan]

Guys, anyone with some ideas about this problem? Help!!

[Bean]

some 4A-GE setups came with a idle air/fuel correction screw, not sure if yours has it (basically a screw potentiometer with an L and R, beware only turns 260° and is sensitive to over turning).
First I would adjust you idle to normal levels though as it should be somewhere around 800 not 1000

[heshan]

Thanks Bandit..

Do you have a diagram to point out the idle air/fuel correction screw? Mine is an AFM model 4AGZE off a 89 MR2.

I'll reduce the idle to 800 and do the test and check..