[LANDY96]

Ok, to start off I have a 96 Disco 5-speed. I decided I needed to clean out the pcv valve on the valve cover. It was totally clogged. I got that all clean, I have replaced all the pcv hoses as well. I replaced the stepper motor, as I broke the old one when I was cleaning it. After all this she ran perfect for about a week. Then as I was driving it one day, while I was shifting between gears the rpms would rise up to 3000 and hang there. If I came to a complete stop, the rpms would drop down to normal in just a few seconds. The next day, at a cold start the rpm would rise up to 2000 start to fall, then rise back up to 2000+ until the engine is warm. The hanging idle between shifting still persists. I unpluged the speed transducer, the hanging between the shifts went away, but the cold high idle startup remained. I have changed the front O2 sensors before, about 30k ago. PLEASE HELP!!!!!!!!!! I don't know what else it could be!!!
THANKS AHEAD OF TIME!!!!!!!!!

 

[dent]

next time that happens when you first start up and if the idle is high.. give it a quick bit of gas and it should drop down...
take care
sam

 

[LANDY96]

Thanks, but it is way past that. I believe now, that the adaptive computer needs to be purged. After a part has been changed that affected air/fuel mixture, the computer cannot re-adjust to prior settings, because now it has 2 or 3 different settings, and it cannot destiguish between them. It is now confused. This is what I have been told by 2 different Rover shopes. I am not going to dealer, as they can not get their head out of their A$$. I hope this helps some-one out there.

 

[barefoot]

this is scary but...that actually sounds right! i had a similar problem that did not go away until purged. apparently, as you were told, the comp. made too many adjustments to return to baseline. let us know if purging does the trick...

 

[LANDY96]

Yes it did. That was my whole problem. Purged the adaptive memory, and she fired right up. Everything is working perfectly, and the check-engine light is off!!! WHOOOO HOOOOOOO! A little advice, if you don't know what you are doing seek professional advice!

 

[kevine]

Purging the adaptive memory??? please explain. :dunno:

Thanks

 

[LANDY96]

Well, your Rover, if something is not working correctly, (from what I have read so far),will resort to changing air/fuel/o2 sensors mixture, and other things to making the car run, automaticly. Like I had a plugged pcv valve for atleast 30,000 miles, perhaps more. So this changes the air/fuel ratio. The computer will then adjust/compensate automaticly for this. The problem is, if the situation is fixed it cannot go back to its original setting. The "adjustment/compenation" is "burned" into the memory. The memory has to be wiped and reset. Like a CD-RW A program has to be run to erase the memory, an Re-Write the original settings. The on-board ECU has the ability to, once wiped of adaptive memory, to re-ajust the fuel/air/o2 settings. I am not totally sure, but this may be part of what is called "limp home mode" Do more research on web for this. As will I. I hope this helps/explains. I am still learning, I have owned my Rover for 2.5 years, there is still much to learn!