Moderator- let me know if this is better posted in another forum before I second post it, thanks.

I've asked here before and didn't get a fix so I'll try again. The problem is that any time the temperature is below 40F the idle on the 1st start of the day will go to 1600-1800 rpm area and take 5 minutes to get down to 1200 rpm where I'm comfortable putting it in drive. I've got quite a bit of experience in OBD and yes cars do idle higher than normal when cold, or 1st start of the day, and then slowly goes down, but 1600-1800 is too high and too slow to come down. Waiting 5 minutes every morning at above freezing temps is excessive and somethings wrong. Made several trips to the dealer including leaving overnight. They replaced the MAF last year as a guess as there were no codes, it fixed the problem and now this year its back. Dealer now says its normal and they all do that. The next closest dealer would make it a 4 hour ordeal. Anyone experience something similar or have any ideas?

Thanks

Hi im not sure if its the same problem as i have with my 07 tucson but see the thread " my car has been in the garage for two weeks". clueless bout cars, whats an MAF?

Our car problems I think are quite different. MAF is the mass airflow sensor and it along with other sensors tell the engine the appropriate amount of fuel it needs for current conditions. If it or a few other sensors provide bad info like telling the computet that it 20F when its really 40F the fuel flow would incorrect and cause a high idle. I've been doing OBD repair for friends for about 15 years and have taken several classes on OBD systems and have a moderately complex OBD scanner so I'm quite familiar with the systems, just can't fix my own car. I called another dealership and explained the problem and they said it was normal also, which I don't believe is true. My experience with Hyundai dealers has been very poor and thee "worlds best warranty" is a joke. Parts are never in stock, they've overfilled the oil by a quart one time and even looking at the dipstick themselves didn't want to fix it as they said it wouldn't hurt anything...WRONG! The car was a good value new with all the safety equipment standard and the base model was perfect for my needs, but god help you if you ever have a problem and need warranty service, its just not there.

Dear flyted and Clioc,

I did a search under the Tech Service Bulletins for your problems and nothing shown yet. You definitely have an unusually high idle, and something is wrong.

1) A bad MAF could cause this.
2) A bad IAT could cause this. Are either of you running a $20 performance chip...these override the the IAT with a resistor to give a false cold reading to the ECU.
3) You might consider clearing the memory of the ECU to reset the settings back to factory default. Disconnect your battery negative cable, turn your ignition to the ON position for 10 seconds, and reconnect your battery cable. The car should idle at a normal 1100 rpm cold and drop within 60 seconds to 800 rpm.
4) If this fails, ask the dealer to reprogram/reflash your ECU. Many times the dealer gets a software patch/ECU upgrade and you will never know about it unless you ask.

Byron

They replaced the MAF once and it fixed the problem for that winter, they refuse to replace it again w/o a code. No cheap chip and no code on the IAT and coolant sensor shows correct OAT. Did the reset for the ECM, no change and dealer did reflash with no change. Odd that both my dealer and another dealer 40 miles away says its normal to idle that high and to have to wait 5 minutes before you can drive off at 40F. 800# no help. Can't find another 2.0L Tucson that does that yet dealer says we won't replace anything w/o a code even if we see it. Period. Odds are very high that its a sensor, but unless I start replacing them myself, Hyundai is no help. Warranty work has been very poor. A call by my service mgr to the tech line, he said, verified All Hyundais idle like that below 40F. Another classic example of "worlds best Warranty" crap Hyundai markets.

Dear flyted,

Your Tucson cold start idle is still not right...but you already knew that.

Since the dealer will not perform another MAF sensor replacement without a Check Engine Light, we can try two more things:

1) Inspect the two cables running to the throttle body. Do both the throttle cable and cruise control cable have just a little tiny bit of slack in them? They are supposed to have this slack to allow the throttle plate to fully close. If not, you can adjust the slack in the cable by the two 10 mm nuts on the bracket. Just maybe, the cable is taut and holding the throttle plate excessively open
2) The MAF was the problem previously. Can you inspect the MAF to insure the connector is clean, not tarnished, no water in the socket, makes a solid electrical connection? We did have one forum member fix a problem from water in the connection socket male end on a Sonata. Can you inspect inside the MAF housing for any oil or grime? Just maybe cleaning the MAF with an approved MAF cleaner will restore your normal idle.

Byron

I'll try those options and let you know. Thanks.

Hello, Flyted I remember this form your first posting on this subject.I did and still have the high RPM start. Have done everything to try and sort out the problem but have had no luck in finding a fix,, however the following works for me, before starting, pump the brake pedal until it becomes hard and then start the car as normal.If I do this, mine never starts with the high RPM no matter how cold it is but if I forget to pump the brake pedal then I start with high RPM's again.
Now I Know it's no fix, but at least it stops the hard start on the engine, and perhaps this will enable someone to identify the real problem with a suitable fix.
??????? Good Luck

Its warm enough for the last several months that its not been an issue, but thanks for remembering and giving me the info and I will try it next time it gets cold. My plan was to wait for it to do it again, then use MAF cleaner on the sensor. Several mechanic friends said these sensors can act funny, yet not give a code. Another post I made is that Hyundai admits that on the 05 through 07 and maybe 08, on the 2.0L that they used the wrong engine oil dipstick and that the manual recommended refill will show an overfill on the stick by about 1/2 inch. Dealers have been advised to continue the manual recommended amount even if it shows overfilled, and advise the customer. Hyundai, from last time I called them had no intentions of putting the correct dipstick in the affected vehicles.