OK so here is whats going on,

first off lets get all this info taken care of

the car is a 86 gxl all emissions intact execpt precats removed for a RB header

still has main cat, split air pipe, aip pump, acv ect....

it has a atkins rotary rebuild with 2k miles on it (stock port)


So I took my car to my local smog shop in seaside, Ca for a smog check, after the smog tech runs the car he says he thinks that its running rich , so instantly im thinking my water temp sensor that screws into the bottom of the radiator , which is hanging down on my undertray behind the rad. Only because my radiator does not have a bung to screw the sensor into. i try to do a quick fix and just took the senor off and jumpered the two wires,because i know the sensor is just a variable resistor , so basically i was thinking the sensor being out of the rad it was not conducting heat from the coolant and either raising the resistance or lowering the resistance of the sensor and therefore giving a false reading to the ecu. so after i jumpered the wires for the sensor and had the tech test it again same results
it did not make a difference the car was still running rich and the tech told me
and it makes sense that the ecu is stuck in open loop and running rich for warm up

so guys i need help some anything input is appreciated

 

In the 2nd Gen FAQ there's a procedure to use just before taking the car to the smog shop. Read it and see if this helps your problem.

 

because the temp sensor is on the water pump housing. right near where the thermostat is.

 

The sensor on the bottom of the radiator on early RX has little to do with emissions once the engine gets up to working temperatures. The water thermos sensor on the back of the water pump housing has quite a bit to do with the fuel delivered and you might check that one. But even if that one was disconnected or thrown in the backyard, the ECU would default to 180* which is normal operating temperatures.

You need to check to see if your car is going into closed loop. Closed loop only happens over approx 15mph give or take and not at a lower speed. You need to backprobe your 02 sensor wire at the ECU to make sure the ECU is seeing a signal from the 02 sensor. Normal reading at idle with ACV and airpump will show it outputting a real low figure like .02 vdc as a general figure but if you idle and see the low figure at idle and THEN go pull the blue colored plug off the Relief solenoid, the figure will come up to something like 0.8 vdc. What you did when pulling the blue plug off is cause the ACV to NOT send air to the exhaust ports thereby making the 02 sensor see only air coming from the exhaust ports and not mixed exhaust air mixed with fresh air from the ACV.

That seems a easy check to see if the ACV/relief solenoid is working.

You really need to post the figures from the test done at the test site. The figures for the 15mph test and the 25mph test. A lot can be determined by seeing if the results got better during the 25mph test or not. A considerable better result in the 25mph test means to me that the ECU is going into closed loop. If it goes into closed loop and your numbers are still real bad, then the converter might be toast.

A car going into closed loop with a good converter should show acceptable results.

The only fuel trim on a early RX is thru the varialbe resistor and that only applys to idle speed, not driving at all.. Helps to have the timing spot on. So post the results of the test.

 

1: Does the car have the Original cat?..if so Replace it.
2: did you do a tune up on the car before Emissions?.Plugs,wires,Fuel and oil filters etc?
3: post the results of the test so the Guys here can give you advice.If they can see the results they can help!

 

still dont have the results of my test i will try to go smog again after putting my stock precats on.

i was thinking i have a bad cat because it is the original.

Another thing I know is the rb header is blocking off the port that injects air at the exhaust ports would this cause me to fail emissions?

 

To work well, the cat needs air pumped into it. So if it's blocked off, that could indeed be part of your problem.

Replacing the cat is always a good step. But I wouldn't throw away your old cat or molest it in any way for the new cat. The aftermarket cats burn out relatively quickly compared to the stocker. So as soon as you pass the smog, remove the replacement cat and re-install your stock one to preserve your investment and be prepared for your next smog check.

 

we need to see the results from the test...

it will make this easier.

screw emission testing. im so glad IL went to 1996 and newer obd2 testing only.

 

Still no test results hopefully tomorrow I will be going back to the smog shop for another go.

I have also replace my RB header with the stock manifold and a new magnaflow maincat and precat.

So ill let you guys know whats going on tomorrow and have numbers for ya If I dont pass
thanks for all of the input guys.



Just so you guys know down here in monterey county they do not require the testing with the engine under load so no 15 or 25 mph tests.

 

passed smog with flying colors with the new cats and stock exhaust manifold on thanks for all of input guys.

Now time to put the headers back on hahaha