OK so im having trouble with the idle on my car. Seems to be idling way to rich. I had to turn the Var-res all the way lean to get it to stop bucking. In the process of replacing a couple sensors i made the 2 led tester to check for codes. After hooking it up i kept getting an O2 error code. I replaced the o2 sensor with no change. even after unplugging it it ran the same, still really rich (i'm guessing rich because of me having to turn it all the way lean to get it to idle some what right.) After this i decided to check the ecu. I took out the ecu that was installed and noticed that someone had "chipped" the ecu. it had a lot of bad solder points. So after re soldering the ecu i reinstalled to try again. NO help. Still the same. I decided to get a new ecu incase the po had burnt a chip up on the board plus i had no idea what the specs were on the new chip. So i bought an Rtek 2.1 and installed it today. I still gave me the o2 error code. i tried running a wire through the firewall and just re wiring it to the ecu at pin 2D as per the FSM. still no change. Im out of ideas. Can anyone think of something i missed? TPS is working correctly. I reset the maps back to factory on my rtek before trying all this. I went through the initial set coupler setup and still had to turn the var-res all the way down to get it to idle right. PLEASE HELP!! If i missed some info to include please let me know ill supply whatever i can. Thanks in advance!

 

its an 87 s4 TII forgot that

 

What voltage are you getting at the sensor's ECU pin? This sensor should not affect idle as it is used for cruising purposes. And a cold engine will throw an Oyxgen Sensor error code.

 

My voltmeter is at work ill bring it home tonight and test that tomorrow. The pocket logger software for my rtek said the engine was it temp (170ish) when i checked the codes. The temp thing is another problem i was having. My car's stock water gauge wont come up much above the "C" on the guage even after idling for an hour or so. This was the other sersor i was changing. But if the pocket logger knows the car is it temp it wouldn't throw a code because the gauge is reading cold would it? I know im asking a lot of questions and i do appreciate ur help satch. But do you know why i would have to turn the var res all the way down to idle better?

 

If the engines combustion was not up to par then perhaps this could cause the engine to run rich such that a change in the Variable Resistor is required. When adjusting the resistor are you jumpering the Initial Set Coupler? The FSM suggests so but others will say it is not necessary. And are the injectors stock sizing? And can't you do any fuel change via the RTEK? And if the engine is warmed up I don't think it matters that the faulty temp sensor matters as the temp gauge does not run to the ECU but it is another temp sensor which is used to tell the ECU temp related info.

And you can use the twin LED lights to test the Oxygen Sensor by connecting them to the Green check connector w/four wires by the lead coil.

 

No I wasnt. I hadnt heard that. Well ill check my plugs and wires and go from there. Still unsure why im getting t. O2 error. Thanks so much man!

 

Post #10

https://www.rx7club.com/2nd-generati...ast-2k-856697/

 

Thanks going to definitely try that!!