If your name is "FordGuy" and you just sent me a PM, I cannnot respond. You are so new, you are in a probationary period. Here is what I was going to send back to you:
FordGuy said:
Hi, I have been lurking here for awhile reading everything I can about my misfire and with 118k on the car I just bought a few weeks ago, changed out the plugs, coils, oil, did the seafoam, and cleaned the MAF, I still get the #1 cylinder misfire on cold starts, and at high RPM (Usually passing in 3rd). I am aware the high RPM issue could be a bad injector, but the bottom line is, it won't hurt to clean the gunk out.
So, can I ask, what part of Austin you are in, and if you are still offering the $300 cleaning?
Sorry, I stopped doing the cleanings some time ago in order to focus more time on work.
The majority of valve build up comes from the PCV gases being piped into the intake tract to be ran through the engine and burnt up, except much of it sticks to the valves. Best thing to do is install a modified PCV system to prevent further valve build up ...either a recirculating catch can setup, or an exhaust-routed PCV, which is the ideal option. There will be very minimal valve build up on the valves no matter what you do, because of oil dripping from valve guides, but a modified PCV will stop the vast majority of it.
Most of what you can do is focus on keeping injectors as clean as possible. I use a bottle of injector cleaner every third tank. The best on the market is Techron. Not the regular Chevron injector cleaner; it must be the Techron which is propriety from Chevron and is patented. I also switched to using Chevron/Texaco gas since both add Techron to their premuim gas.
Use of these fuel products and an the exhaust-routed PCV has kept my car running smoothly more than 70,000 miles since my last cleaning. Car just passed 150,000 miles and is running well.
If you have a 2006-2008.5 engine, make sure to change your cam follower every 40,000 miles (if stock engine) and use a high-quality European full synthetic oil. These oils meet more strict requirements than what the US says can be a "full" synthetic. Motul, Liqui Moly, Total, Eneos, Pentosin, etc. are all good. Ester oils are even better, such as Motul 300v and all Redline oils. These higher quality oils will aid in making the cam follower last longer, as well as making less oil in PCV gases due to their lower volatility properties.
So those are the big four things you can do and your engine should be good for 300k miles or more. Keep your injectors clean, modify your PCV, change cam follower every 40k miles, and run good oils. Good luck.