Author Topic: 1985 22re in Open Loop  (Read 3097 times)

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BDM

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1985 22re in Open Loop
« on: Mar 28, 2014, 04:48:26 PM »
Hey all.  I have been around these forums for years using the search function and have learned a lot from everyone but I am now stuck and could use some help. 

I have a 1985 SR5 4runner 22re 5 speed that I have been at war with trying to get a smog cert.
The truck runs great, has no performance issues, and sounds great. 

Engine specs:
Pretty much stock 22re
LCE Header
LCE intake with K&N filter

I first did the basics:
Timing to factory spec (also tried timng retarded 3 degrees)
New cap and rotor
New plugs/ plug wires
Adjusted valves to factory spec
Ran 91 oct with RXP gas kicker
I cleaned out the EGR and tested it bc I failed off NO the first time.
EGR works correctly
I put on a new magnaflow universal catalytic converter

O2 Sensors stuff I have tried:
-Universal bosch 1 wire
-Bosch heated 4 wire
-Denso factory replacement 1 wire

-I put the header on 2 years ago after smog last time (it passed).  I cracked my stock exhaust manifold and needed a new one.  The header came with a special deal on the intake at the time so i got it.  The LCE header moves the o2 sensor down stream about 3 feet so i went ahead and welded in a new bung approx 10" from the head on cylinder 3 header tube.  Ever since I put that header on I get the common check engine light while cruising at approx 2500-3000rpm.  Code 5 (o2 sensor). 

-When i test the o2 sensor (doesnt matter which brand or position it is in) I get roughly -.30 DCV with it plugged in.  When I unplug the o2 sensor and test the o2 sensor end of the plug I get around .6 to .8 DCV which sounds to be good.  With it unplugged when i test the end that is going to the ECU I get roughly -.30 DCV.  I believe it is in open loop and the ECU is blocking the input from the o2 sensor.

I then tested and replaced the ECT (engine coolant temp) sensor.  The old one tested correctly but looked extreamly old so I replaced it anyway bc i thought that this was the main reaseon the truck is in Open Loop (if that is what its in.?.?)
The ECT now works correctly.
I also put in a hotter thermostat 192 degree bc i thought the engine wasnt getting hot enough. 

These changes made no difference with my o2 sensor readings.

I then swapped in my friends ECU from his 4runner and everything worked the same as my ECU.  No change in readings. 

Smog test with best results so far:
15mph @ 1646rpm
CO2  11.5
O2  3.9
HC 168  (fail)
CO  .80  (close to fail)
NO  930  (close to fail)

25mph @ 2580rpm
CO2  14.4
O2  .9
HC  95  (close to fail)
CO  .49
NO  855

I am now going to try to get the truck to pass in Open Loop and it is apparently running lean.  Everything that I have heard is that they should run rich in open loop.  My plugs are new but they still look good.  I have adjusted the wheel in the AFM that changes the air fuel ratio.  I moved the wheel counter clockwise three teeth in an attempt to lighten the spring tension that closes the door.  Hopefully this will make it a little more rich even though it is in open loop. 

My question is

Is there a way to tell if the truck is in Open loop?  Does anyone know what the o2 sensor should read in open loop?
Is there a way to make the truck go into closed loop manually? 
Is there anything that I have missed or need to check? 

Thank you for any feedback.  Glad to be finally posting something to these boards.  Sorry for the long post with probably a ton of spelling errors haha.

SNOW WALKER

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Re: 1985 22re in Open Loop
« Reply #1 on: Apr 10, 2014, 08:24:09 PM »
The only time the ecu is in open loop is at idle and part throttle. Once you are at wide open throttle it goes into closed loop mode. With all of the 02 censors you have tried and changing the ecu I think everything is fine. I bet it will pass with the air meter adjustment that you made  as long as you turned the clock spring in the right direction.
1986 4Runner turbo sas high pinion,E-locked 4:88's,taco rear Detroit locker,22ret forged everything,
duels mc07-r10 cut 42's.

emsvitil

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Re: 1985 22re in Open Loop
« Reply #2 on: Apr 10, 2014, 08:53:11 PM »
Retrofit a heated O2 sensor (3 wire is fine, 4 wire if you don't  trust it being grounded with the header).

I tapped off the Ignition circuit to run the heater.    This will help if the O2 sensor cools off too much because of it's downstream location.

There is a test connector in the engine compartment that you can connect a voltmeter too.     You should see the voltage bounce back and forth (old analog meter works good).   It should center at about .5 volts.


The EGR system needs backpressure to work.   

I have a cat-back system and at a restriction after the cat for smog testing.


http://board.marlincrawler.com/index.php?topic=35329.msg412022#msg412022

http://board.marlincrawler.com/index.php?topic=95620.msg1066400#msg1066400
Ed
SoCal
86 SR5 XtraCab
22RE  W56B
31x10.50R15

 
 
 
 
 

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