fluctuating idle

[KeithElisa]

I have some strange idle problems with 97 D90. My idle keeps dropping so low the engine cuts off. It comes and goes off and on. I have changed the fuel filter and the air filter and pulled out the air idle valve and cleaned it. Anyone had this problem or have any advice?

Thanks,
Keith

[Mike Hippert]

If you have not checked it out yet look here (http://www.d-90.com/faq/Engine/EngIgn.html). I had a similar problem, the plugs on the distributor cap were corroded. I also ran some injector cleaner threw the system and the problem went away.

[evilfij]

Replace the Crankcase breather hoses. They are plugged and contributing to the fault. Next check the vacuum lines. Also make sure you are not low on oil.

If this does not help you have an issue with a sensor out of spec so you will need to trouble shoot further.

Ron

[Mike Hippert]

Keith, I like the Avatar! who is the young driver.

[Mike Hippert]

doh! double post!:mad

[scot]

Another possibility is the stepper motor....it is part of the gizmo that sets the idle, and I have had one go bad before. I don't know if that is the same part you describe as the air idle valve, but it could be. My first truck behaved exactly as you describe your problem. They (stepper motors) can be removed cleaned and lubed if they are failing and sometimes they will work well for another year or so. But as I said...I ended up having to replace one...which sucked. I can't remember how much I paid but it was a few hundred dollars.

[KeithElisa]

Mike, That would be my son and future land rover driver, Colin. He's just turned one. My 3 year old daughter Leah loves rovers also.

[mikeslandrover]

Air flow meter is probably at fault

[KeithElisa]

Where would that be located?

Thanks,

[nmarkiw]

I assume from your profile this is a 97. GEMS. Is the check engine light on? Has the battery gone dead or been disconnected recently? If so, the adaptive variables may need to be reset. (Requires a Rovacom/Testbook/T4) The TPS could be out of adjustment or faulty. If the TPS is not below 13%, the GEMS won't control the idle. This can be tested with a volt meter.

A generic OBDII scanner can verify these.

Nick

[KeithElisa]

Yes, it's a 97 and the check engine light never came on. But I do have a battery disconnect on my ground terminal that I keep disconnected for up to a week at a time. The reason for the disconnect is I have a mystery battery drain that I could never find.
I don't have a test book or a scanner. I hate to go back to the dealer they never seem to find or fix anything but I think this problem might be out of my league. I do have a volt meter and a shop manual.

Thanks,

[Doug]

Post on the www.LRX.com forum, and Mike Green will give u some ideas I'm sure -- he is a genius IMHO.

DW

[kkaiserblu]

hello

I was wondering if you could show me or tell me where the steppor motor is exactly?

[redrover]

X marks the spot. JP

[Hoss]

My money is on the stepper motor. When it is faulty you will get a fluctuation that sounds like your issue. The part is not cheap, but it is an easy replacement.

Good luck with the fix.

[Heath]

I have had problems that were related to the speed transducer. The transducer did not throw a code for a long time... it threw a lambda sensor code (44 or 45 i think). I did switch the idle stepper motor, several hoses, and tested throttle position sensor, set base idle, rotor cap, distributor coil (with mallory unilite), and the o2 sensors.
All of these things can cause idle problems. Could it be related to speed. When you slow down? Randomly? And as for the stepper motor, you can get one from NAPA.