Location is not far from the Portland OR area. I took the IACV off agin and found a gasket it on it. Didn't see it the first time.

When you reset do you have to wait for the computer to do all it's tests again before it can pass DEQ? I'm currently waiting for this to happen so I can pass DEQ. They said it may have happened because I recently had a dead battery, could that be the case?

 

I doubt you'll get it to start let alone idle with it disconnected but anything is possible, it's a Rover..... Try it, aint gonna kill it. Give these folks a call; Green Oval 2046 NE MARTIN LUTHER KING JR BLVD, PORTLAND, OR 97212 Tel: 503 232 0049

 

I disconnected it and I had the exact same problem. It would idle decent at low temps. And once it warms it it goes to high idle then does a series of step downs after a period of time.

So I don't think it's the idle control valve?

Could it be something with the mass air flow sensor and its riching the mixture? What would happen if I disconnect the MAF? Or someway to test it?

Other things I can test?

Or maybe this means the idle control valve is not working?

Thanks again for any help.

 

Do you have a Check Engine Light on? If so can you pull the code(s)? When there's a failed sensor it would absolutely set off the CEL.

 

No CEL on.

In fact the "Emissions Readiness" test of my ODB2 reader says that Catalyst, O2 Sensor, and O2 Heater are incomplete. And because of these I can't pass DEQ currently. I ready somewhere else that I have to drive around at different speeds for a while (there is a checklist of what is required, but I can't find that right now.) So I guess my computer is still trying to figure out if the sensors and system is functioning properly. Wish it would hurry up.

 

My high idle and stumbling issues were caused by a bad MAF. Unplug it while it's running and see if it changes the idle. Mine would idle like complete garbage with it plugged in, and then smooth out when I unplugged it. Installing a new MAF cleared it up completely.

Also, FWIW going on 3 months of driving and 2 months post emission pass, I still have an incomplete reading on my catalyst. I'm not sure it speaks a language my scanner can understand. Everything else shows ready. I think you just need drive time at varying speeds/RPMs to get them ready.

 

I tried with MAF unplugged. And at low temp it ran very rough when unplugged and then better when plugged in. At normal operating temp then engine just dies when the MAF is unplugged. It sounds like my MAF is working?

One thing I did note is the high idle issue starts at 140 degrees F. I wonder what other tests I can do?

 

Ecm reset with scanner is my guess, that fixed my 98

 

ECM reset didn't fix it Took it to local rover shop and cost $55. (The reset did seem to fix the SRS light)

So I'm back to square one. I have a high idle when the engine temperature goes above 140F. ECM replacement? I'm grabbing at straws. but along those lines I have a few questions.

do I want part # ERR7109 (GEMS 8) for my 96 land rover disco? Also does it make a difference if the ECM came out of a automatic if my vehicle is manual? I can get a used ECM for about $40.

btw: I also pulled my temp sensor and verified it's working. Since this high idle only happens above 140F I wanted to double check the coolant probe. In fact when I disconnect it I can see the temp shuts off on the ODB2 monitor.

 

On the plenum at the throttle body there is a hole with a metal tamper cap, has that cap been removed?

On my 98 instead of doing the reset I asked for the dealer drilled that cap and they bottomed out the screw and ruined my plenum, that's when I learned not to take my old 98 to the dealer, expensive lesson