Cold start misfire

Yes I did bg, and crc is it possible that the temperature sensor is giving a false signal to the computer or perhaps there is an update on the computer?

Roy, Thank you so much. I will hunt it down and give it a try, Charlie

Roy, brought it into the shop 5mm. Of carbon, they told me to bring it to Hyundai there ts an update 12-fl-007 which must be performed before repair. They told me the update may fix the issue if not, valves need to be cleaned removing the intake soaking the valves in solution. Does that sound correct, they also told me regular induction will only remove 1/2 to 1 mm of carbon. Thank you so much, Charlie PS: if I continue to use tier one gas, more frequent oil changes, and induction cleaning would that remedy the situation.

I originally meant removing the intake manifold not the heads to soak the valves in solution. Well, I went to Hyundai today they said there was no update on the computer but I had them do that GDI service which was expensive comparing it to me doing it myself through the throttle body. They went through the fuel rail, and they were quite thorough. They suggested as you said more frequent cleaning, I can do that myself was just wondering how often can I do that going through the throttle body. Did not want to cause harm doing it to frequent. Thanks again, Charlie

I shall. Thanks again.

Still trying to figure out the problem, had it walnut blasted for carbon no change. It has something to do with operating temperature with the ECM. I know the coolant sensor has multiple purpose, if that is the problem I will be kicking myself after spending $2,000.00 on it so far. A few other posts had the same problem and the remedy was the coolant sensor not setting off a code, really strange.

Roy, An update on the Genesis, the shop that did the walnut blasting said the good news is no carbon. The bad news the carbon did damage to number six valve seats recommend valve job $2,300.00. If that is the problem for what I paid for diagnostics, valve cleaning, walnut blasting I could have paid for a valve job. Roy, after all of this expense the car runs exactly the same. Aside from torching the car, what do you suggest? I have driven the car in this same condition for about a year no change at all.

They said compression was fine, something about leak down and recommended a valve job.

Interesting, it needs a valve job yet the compression is good in cylinder number six? They told me when the car warmed up because of the carbon build up the valve seated and ran smoother. Now with all the carbon gone if it does exactly the same thing they are not being truthful. They did a manual cleaning with chemicals taking off the intake, then when it ran the same they did it over again with a walnut blaster that they said they ordered in. I told them cannot afford a valve job, they said we will put it together and you can pick it up on Monday. I am curious to see what they are going to attempt to charge with the walnut blasting. I wish I can just find and honest repair shop. Thanks Roy, God bless you.

Will do, thanks.