O2 Relay - Surging Fix???
 

My car pulls like a train from startup until.......it gets around 185 deg. Once is gets hot, it starts to surge at idle, then finally dies.

The a/f is 2.7 so this is not the culprit.

In searching the archives, I started to mess around with the O2 relay. Now, I am a little bit confused as John Walker said that if you unplug it, the car should run rougher. However, in my case, when I have the surging issue and I unplug the relay, the car stops surging and never dies. In other words, the car runs like a dream without it.

What gives? I have a relay ordered but I am just wondering.

Thanks.

:rolleyes: :rolleyes: :rolleyes: :rolleyes:

you mean the CO is 2.7%? the CO is measured with the O2 sensor unplugged, before the cat if possible. unplugging the O2 relay would lean the mixture, so maybe it's way too rich initially, which is the usual cause of idle surging. set the CO to 3% and leave the O2 sensor unplugged. set idle speed to 1000 and see what that does.

John,

As always, you are a gentleman when it comes to knowledge transfer.

However, I just fixed my computer (it died for a week), so sorry for the late response. As an update, it turned out that the fuse (although still connected to the fuse box connectors), was not sitting IN THE hole. My suspicion is that as soon as electrical load and heat built up, the pointed ends of the fuse was not sufficient for the load requirements....resulting to intermittent power to the sensor.

In other words, I removed the fuse, reinstalled it correctly so that the bottom was actually centered into the hole, and VOILA problem fixed. I have sinced sanded ALL connectors with some application of dielectric stuff.

Oh, and my CO is now back at 3.0! Now if I can just have the time to try your ultimate 3.5 CO at 6K setup!!!!???????

the fuse powers the relay, which powers the o2 computer, which operates the frequency valve, which makes the engine run properly. it does not actually power the o2 sensor. the o2 sensor just gives signals to the computer so it can adjust the speed of the of the frequency valve. unplugging the o2 sensor when everything else is working properly takes away the surge when cruising, and gives a better, smoother idle, especially when set to around 3% CO. it's kind of an add-on system that you can live without, except for the emission test.

Yeah, sorry. I meant 'power to the relay'.