Okay, sorry it's been a while. I checked all 4 O2 sensors, they are good. As far as I can tell everything tested out good. However, this morning, for the first time ever, the Disco acted normal...it also happens to be the first morning I have driven it when the outside temp was below freezing. So I looked in the Rave again, realized after all this time I had the shop manual not the complete RAVE. Downloaded the entire RAVE, went through it and can find no values for the ECT, Fuel Temp, IAT sensors when cold. I want to chewck the values in the morning(cause it's supposed to be cold again) to see what they are reading then, and check the values again when the engine is warm. I found values for the MAF, but not for the temp sensors. Anyone have those valuse lying around or know where in the RAVE they are? Thanks for all the info in the past and for the upcoming info.
Wish I could give you more info regarding driving the Disco, but I only drive it on the weekends because it is the wife's car...(someday I'll get my own)

 

So I tested the MAF. When I blow lightly through the MAF, I get a reading of 1.4V. It drops off to >.5V when I stop blowing. I did not check with the vehicle running. Can do later. I checked the IAT, ECT(both) and Fuel Temp sensors. All I could see to do was check that they have voltage at the harness and ground. They do. I checked resistance across the sensor pins. I got O.L(out of limits) for the IAT, ECT(two pin) and Fuel Temp sensors. The other ECT(the one for the gauge) read 300 Ohms(IIRC). But the temp gauge works, so I'm not concerned about that sensor. Any suggestions?
I haven't had the motivation to crawl under the vehicle to check the O2 sensors yet. Been too cold for my blood(yeah, I'm a wimp).

 

I would not say it was o2 sensors. Without rereading the whole thread all I can say is my tps was bad and ecu was in limp mode. Reset ecu and it went back to limp mode eventually. Changed tps and reset ecu and all is fine

 

I somehow missed this info. When I checked my ECT(cold) it read OL(out of limits/infinite). But so did the Fuel and Air temp sensors....maybe I should not rely on that Crapsman DVOM and take my Fluke home to use...

 

I managed to test the ECT, MAF, IAT, TPS, FuelTemp, IACV, O2s. Everything tests fine with a meter, but when I read live data with the scanner, I noticed my scanner will not read the MAF, but the MAF is reading correctly when I test with a DVOM whil the engine is running. I also noticed that when the engine is idleing correctly, the O2 sensors read correctly, but when the idle is high, the O2 sensors sit at 1.25V, and do not jump around from lean to rich to lean again as they should. I am looking into replacing the IACV(I can get a new one from NAPA for $56) and seeing if that makes a difference. I also noticed I do not have the gasket between the IACV and the TB...will that throw off the IACV reading? I am also wondering if I should pull the ECM and see if there is any corrosion in it...if that is giving me problems. Any thoughts?

 

I think the absence of the gasket between the TB and the IAC can throw off your idle. You might want to start with a 0.50$ gasket rather than the 56$ IAC. The ECU is in a very bad place, it catches corrosion very easily. When mine went bad, it caused relay to click frantically under the dash and the truck to run like crap. But after 30 second everything would go back to normal.

 

I went ahead and ordered an IACV and Gasket. As soon as they get here, I'll change them out and see what happens.

 

I know a few of the Rover suppliers do have the correct brass plug to replace that plastic one,I was going to get one eventually as well as a new overflow tank.

 

Isn't that indicative of the a high resistance condition, like possibly a degraded connection? It's not open circuit, but staying at one value like that is puzzling.

 

My buddy with a heated shop just got back from vacation. We are planning on looking at the grounds weekend after next. Been too cold and wet, leaving no desire to crawl around on the ground in my driveway.