I haven't used any gasket sealant due to fear of contamination. I have used NAPA silicone spray lube on the car at various times. I don't recall ever directly injecting it into the engine but over 7-9 months, who knows? I am using Mike Cohee's analog dwell meter. I will refer to the manual section you've called out. I was unable to perform any tests or repairs because we got hit with an unreal storm just as I pulled up in front of my house. Every tree in the median outside my development was torn down before my eyes blocking the road. Not saplings either. I then looked at the tree next to my car, and relocated the car to the middle of the parking area just in case. I think little silver cars are good luck or something. Rich #5335 -Md --- In dmcnews@xxxxxxxxxxxxxxx, "David Teitelbaum" <jtrealty@xxxx> wrote: > Usually an O2 sensor is not damaged from an overly rich mixture. When > you finally lean it out it will come back to life. You CAN damage it > by contamination. If you do not use "sensor safe" silicone gasket > sealer you will not only ruin the O2 sensor currently installed but > any replacements you install! There are tests of the Lambda system you > can do to make sure the rest of the system is functional. Refer to > D:04:15 # 5 A.-E. There have also been cases (not on Deloreans) of > using silicone cleaners on the motor and when the motor was running it > was ingested and contaminated the O2 sensor. If you are using a > digital dwell meter to check the Lambda don't trust it. Most can't > read it right. You really need an old analog type with a needle to get > the readings you want. Remember we are dealing with 80's technology so > you have to try to use the test instuments that the people had > available then. > David Teitelbaum > vin 10757 > > > --- In dmcnews@xxxxxxxxxxxxxxx, "cruznmd" <racuti1@xxxx> wrote: > > Can you ruin an O2 sensor with a super-over rich condition or with > > excessive heat, say from a glowing cat? > > > > The dwell meter on my car says the lambda computer and hence the freq > > valve are not operating properly. > > > > Since I've been told by multiple sources that the ECU almost - never- > > dies, the O2 sensor is the most logical next item. The problem is, > > mine's nearly new. I did have it installed way back when my fuel > > system was totally hosed. I got the cat converter to glow cherry red > > a few times. > > > > Thanks, > > > > Rich