First off no codes.... on cold start up RPMS jump to around 2k for about 1-2 sec then back to normal. It worrys me because I really dont like a cold engine running that high b4 the oil is circulated. Here are my symptoms...

RPMs jump to 2k intermittently on cold start up for 1-2 sec then back to norm
Occasionally when a/c is off idle drops and is very rough

Other possible related symptoms...
Tranny shifts hard from 1st to 2nd
Misfire on 1 and 6 codes twice when raining (new wires on order)

My research so far is leading me to check idle solenoid, IAC, MAF or possible vacume leak. Is there a step by step for checking/cleaning these items?

Any other advice would greatly be appreciated

 

No codes is an indicator that the ECU believes what it is doing is correct, based on the conditions sent to it by the sensors. So you can't always eliminate a sensor by no codes. If you have a scanner that can read raw data, soemtimes you can see values for things that don't make sense, like -40 F for coolant temp, etc.

You would probably want to clean the IACV and the throttle body first with cleaner made for the purpose, and the bore that the IACV fits into. Please resist temptation to turn or adjust the business end of the IACV. If these don't produce improvement, then move on to the MAF, cleaning it when stone cold and for good measure the can of cleaner stowed with the truck, so thermal shock is minimal. There are parts inside the MAF that heat to over 400F, so squirting them with cold spray cleaner can do bad things. Wires seem like a good idea. If you are where it is 20 degrees or less, might want to consider 5W40 Rotella oil, or similar.

 

Clean out your t/body and Idle solenoid as already mentioned, get your plugs and wires installed and if still have any issues, get back to us.

 

TB, MAF and IACV Cleaned. Wires replaced with 8mm Kingbourne.

First cold startup jumps to 2k for a seconds then back to normal cold idle. It does idle much smoother and with the a/c off as smooth as butter.

I researched Idle solenoid but have yet to find out where it is located...

It does not jump to 2k every time you start it. I have also been noticing my SAI has a high pitch whistle occasionally on start up. COuld this be causing the RPM's to jump to 2k on cold start?

Any ideas?

 

Not sure you have an idle solenoid - see attached pages on engine management system. SAI pump will start making a whine , hair dryer noise, etc, when pump is on the way out. There is a disposable air filter on the pump.

 

First, there is no IAC on a D2, only an idle solenoid which is located on the by-pass hose between the air intake hose and the manifold.

 

Not sure if this has been resolved but I've got a similiar problem. 2003 Disco that starts quick and easy, but the idle will immediately shoot up to 2100rpm for about 2 seconds and then dip down to 1400 and then repeats this 7 times before sitting at 1000rpm for about a minute and then down to 750 or so.... Up and down.. Up and down. New plugs, wires, just replaced the MAF, new air filter.. Replaced the Idle air control valve with a used one and nothing changes. Other than cold starting, it runs fine. A little hiccup at idel in traffic at times but no stalling or any other changes. Considering a new IACV but would apprecite some input before buying another one.

 

Does the ses light flicker when this happens?

 

The green Manual mode light and the Sport Mode light came on and remained on twice but once warmed up, i turned the engine off and once restarted, they both remained off. No other lights flickering or illuminated. Both manual mode and sport mode work appropriately and so do the lights when engaged. Thanks!!

 

probably vacuum leak.
At startup I bet your engine is about to stall
so the ECU cranks open the IAV for air to get the rpms up.

Then overcompensates and cranks the IAV closed.

That's why you get the up down up down.

Check all connections to the MAF are good - the air connections to the rubber
to the MAF are all tight.