940 & 960 Buggered Oxygen Sensor? 1991 940GLE 16valve.
-new fuel filters and ‘newer’ intank pump
-AMM replaces with known to be working 2nd hand unit
-new air filter
-IAC cleaned and operational
-new spark plugs
-KS cleaned and retorqued
-dizzy cleaned; it’s not the best but it’ll be replaced soon with a wasted spark set up.
-good plug leads.
-probably other stuff I can’t remember.
-oh yeah, vacuum hoses done too.
I removed the O2 sensor when dropping the exhaust to fix leaky joins. Discovered, to my great delight, that someone has beaten me to gutting the cat. There’s no pipe in it so it has a really annoying resonance at certain revs
When I was putting the O2 sensor back in I noticed the cable was twisting about itself like a spastic snake.
It’s a weird mental image I know.
I got it all straightened out, took the car for a drive and all was peachy. Or so I thought. It was a short drive, less than two minutes.
Next day, warmed it up before going out and when I got in the car say the CEL on and noticed the engine sounded tougher than usual. Fumey too.
Turned it off, disconnected the battery for a bit then restarted it and same problem.
When driving it, the car was sluggish and phark mee!😳 she loved the fuel! 80km and used a bit over half a tank.
Checked codes, got 232–>running rich (no kidding) or too much fuel pressure.
I checked the signal lead lead from the O2 sensor using a DMM and saw that instead of sweeping from 0.1 - 0.9V it was bouncing around in the 0.1V range. I saw 13.5V supplied in one of the white dot heating so I guess that side of it ok.
i can’t rule out a faulty FPR. I don’t have a pressure gauge. The vacuum line has a mild odour de petrol but nothing more. Diaphragm could be stuffed.
Has as anyone else had an O2 sensor go from good to useless in these kind of circumstances?
Is it possible that during its interpretive dance if the spastic snake I’ve damaged the wiring inside the unit?
Any light shed on this will be much appreciated?
Thanks in advance.