I have 2000 ranger 4x4 3.0 L V6 Flex Fuel truck. Recently I did some major tune ups on it (new plugs, air filter, PCV valve, O2 sensor). I changed those and truck ran good, but check engine light came on. Took it to Autozone and their computer said my Bank 1 O2 sensor was bad (this truck has 3 O2 sensors on it) so I got it changed and they reset my computer. Truck ran fine. Then I changed the fuel filter still ran fine. Now when I first run the truck after it has been sitting for 2 hours or more it will start to miss alot when I accerlate. Then it seems when the engine warms up it goes away if I shut the engine off for a few minutes (like to go in a store) it still runs fine. I've never seen something do this just when it is cold. The wierd thing is it idles just fine. Any suggestions I am open do them I am about ready to take it to my local dealership to have them look at it. Also check engine light does not come on so I don't know what is wrong with it. Also it is about 90 degrees here lately and still does it until engine is warm. Just possible if my other O2 sensor went out I changed the bank 1 before the catalytic converter and the one after.

 

next time it does it, go to autozone and get the codes pulled, whether the CEL is on or not. the CEL doesn't need to be on for codes to be present.

 

You didn't mention plug wires in the list of parts you changed. So, I would start with plug wires. Also, what brand of plugs did you use? I had a "mis"
problem with my 1999 3.0L FFV, due to the prvious owner installing Bosch plugs. Going to Motorcraft double platinums fixed the "mis" problem.

 

Thanks for the info Bob. As a matter of fact I did put Bosch Platinum plugs in my truck. The ones I took out were Motorcraft Platinum. I also did not change the wires. I think I will try changing these and see what happens. Where is the best place to get Motorcraft plugs? I don't think AutoZone sells them do they?

 

I bought Bosch Double Platinums for my truck and a set of motorcraft wires and it runs like a champ all the time. Make sure you gapped the plugs right and consistently. Also you might have cracked the porcelin on one of the plugs. Poke around and see what you find.